To get an idea about a particular phenomenon, to draw conclusions, it is necessary to conduct a statistical study. The subject of statistical research in health care and medicine can be the health of the population, the organization of medical care, various sections of the activities of medical institutions, environmental factors that affect the state of health.
The methodical sequence of performing a statistical study consists of certain stages.
Stage 1. Drawing up a plan and program of research.
Stage 2. Collection of material (statistical observation).
Stage 3. Material development, statistical grouping and summary
Stage 4. Statistical analysis of the phenomenon under study, formulation of conclusions.
Stage 5 Literary processing and presentation of the results.
Upon completion of the statistical study, recommendations and management decisions are developed, the results of the study are put into practice, and efficiency is evaluated.
In conducting a statistical study, the most important element is the observance of a strict sequence in the implementation of these stages.
First stage statistical research - drawing up a plan and program - is preparatory, at which the purpose and objectives of the study are determined, a plan and research program are drawn up, a program for summarizing statistical material is developed and organizational issues are resolved.
When starting a statistical study, it is necessary to accurately and clearly formulate the purpose and objectives of the study, to study the literature on this topic.
The goal determines the main direction of research and is, as a rule, not only theoretical, but also practical. The goal is formulated clearly, clearly, unambiguously.
To disclose the goal, the research tasks are defined.
An important aspect of the preparatory phase is the development of an organizational plan. The organizational plan of the study provides for the definition of the place (administrative-territorial boundaries of the observation), time (specific terms for the implementation of the observation, development and analysis of the material) and the subject of the study (organizers, performers, methodological and organizational leadership, research funding sources).
Pl a n research d ov a nia includes:
Definition of the object of study (statistical population);
The scope of the study (continuous, non-continuous);
Types (current, one-time);
Ways to collect statistical information. Research program includes:
Definition of the unit of observation;
List of questions (accounting signs) to be registered in relation to each unit of observation*
Development of an individual accounting (registration) form with a list of questions and features to be recorded;
Development of table layouts, in which the results of the study are then entered.
For each unit of observation, a separate form is filled out, it contains a passport part, clearly formulated questions of the program, put in a certain sequence, and the date of filling out the document.
As accounting forms, accounting medical forms used in the practice of medical institutions can be used.
Other medical documents (case histories, and individual cards of an outpatient, the history of the development of the child, the history of childbirth), reporting forms of medical institutions, etc. can serve as sources of information.
To enable the statistical development of data from these documents, the information is copied onto specially designed accounting forms, the content of which is determined in each individual case in accordance with the objectives of the study.
At present, in connection with the machine processing of the results of observation using a computer, program questions can be formalized , when questions in the accounting document are put in the form of alternatives (yes, no) , or ready-made answers are offered, from which a specific answer should be selected.
At the first stage of the statistical study, along with the observation program, a program * of the summary of the data obtained is compiled, which includes the establishment of the principles of grouping, the selection of grouping characteristics , determination of combinations of these signs, drawing up layouts of statistical tables.
Second phase- collection of statistical material (statistical observation) - consists in the registration of individual cases of the phenomenon under study and the accounting signs characterizing them in registration forms. Before and during the performance of this work, instruction (oral or written) of the observers is carried out, and they are provided with registration forms.
In terms of time, statistical observation can be current and one-time.
At current observation Yu denia the phenomenon is studied for some separate period of time (week, quarter , year, etc.) by daily recording of the phenomenon as each case occurs. An example of a current observation is accounting for the number of births , dead, sick , discharged from the hospital, etc. This takes into account rapidly changing phenomena.
At one-time observation Yu denia statistical data are collected at a certain (critical) point in time. One-time observations are: a population census, a study of the physical development of children, accounting for hospital beds for horses of the year, certification of medical institutions, etc. Preventive examinations of the population also belong to this type. One-time registration reflects the state of the phenomenon at the time of study. This type of observation is used to study slowly changing phenomena.
The choice of the type of observation over time is determined by the purpose and objectives of the study. For example, the characteristics of hospitalized patients can be obtained as a result of the current registration of those who left the hospital (current observation) or by a one-day census of patients in the hospital (one-time observation).
Depending on the completeness of the coverage of the phenomenon under study, a continuous and non-continuous study is distinguished.
At continuous The study studies all the units of observation included in the population, i.e. the general population. A continuous study is carried out in order to establish the absolute size of the phenomenon, for example, the total population, the total number of births or deaths, the total number of cases of a particular disease, etc. The continuous method is also used in cases where information is necessary for operational work (accounting for infectious diseases , workload of doctors, etc.)
At discontinuous The study examines only part of the general population. It is divided into several types: questionnaire, monographic, main array, selective. The most common method in medical research is the sampling method.
Monographic method- gives a detailed description of individual units of the population, characteristic in any respect, and a deep, comprehensive description of objects.
Main Array Method- involves the study of those objects in which the vast majority of units of observation are concentrated. The disadvantage of this method is that a part of the population remains uncovered by the study, although small in size, but which can differ significantly from the main array.
Questionnaire method- this is the collection of statistical data using specially designed questionnaires addressed to a certain circle of people. This study is based on the principle of voluntariness, so the return of questionnaires is often incomplete. Often the answers to the questions posed bear the imprint of subjectivity and chance. This method is used to obtain an approximate description of the phenomenon under study.
Sampling method- is reduced to the study of some specially selected part of the units of observation to characterize the entire general population. This method has the advantage of obtaining results with a high degree of reliability as well as a significantly lower cost. The study employs a smaller number of performers , moreover, it requires less time.
In medical statistics, the role and place of the sampling method is especially great, since medical workers usually deal with only a part of the phenomenon under study: they study a group of patients with a particular disease, analyze the work of individual departments and medical institutions , evaluate the quality of certain events, etc.
According to the method of obtaining information in the course of statistical observation and the nature of its implementation, several types are distinguished:
1) direct observation(clinical examination of patients , conducting laboratory , instrumental research , anthropometric measurements, etc.)
2) sociological methods: interview method (face-to-face survey), questioning (correspondence survey - anonymous or non-anonymous), etc .;
3) documentary research a nie(copy of information from accounting and reporting medical documents, information from official statistics of institutions and organizations.)
Third stage- grouping and summary of material - begins with checking and clarifying the number of observations , completeness and correctness of the information received , identifying and eliminating errors, duplicate records, etc.
For the correct development of the material, encryption of primary accounting documents is used. , those. designation of each feature and its group with a sign - alphabetic or numeric. Encryption is a technique , facilitating and accelerating material development , improving the quality, accuracy of development. Ciphers - symbols - are developed arbitrarily. When coding diagnoses, it is recommended to use the international nomenclature and classification of diseases; when coding professions - a dictionary of professions.
The advantage of encryption is that, if necessary, after the end of the main development, you can return to the material for development in order to clarify new relationships and dependencies. Encrypted accounting material makes it easier and faster , than unencrypted. After checking, the features are grouped.
grouping- division of the totality of the studied data into homogeneous , typical groups according to the most significant features. Grouping can be carried out on qualitative and quantitative grounds. The choice of a grouping feature depends on the nature of the studied population and the objectives of the study.
Typological grouping is carried out according to qualitative (descriptive, attributive) features, for example, by gender , profession, disease groups, severity of the course of the disease, postoperative complications, etc.
Grouping by quantitative (variation) features is carried out on the basis of the numerical size of the feature , for example , by age , the duration of the disease, the duration of treatment, etc. Quantitative grouping requires a solution to the question of the size of the grouping interval: the interval can be equal, and in some cases - unequal, even include the so-called open groups.
For example , when grouping by age, open groups can be determined: up to 1 year . 50 years and older.
When determining the number of groups proceed from the purpose and objectives of the study. It is necessary that groupings could reveal the patterns of the phenomenon under study. A large number of groups can lead to excessive crushing of the material, unnecessary detailing. A small number of groups leads to obscuring of characteristic features.
Having finished grouping the material, proceed to the summary.
FROM vodka- generalization of isolated cases , obtained as a result of a statistical study, into certain groups, their calculation and inclusion in the table layouts.
A summary of the statistical material is carried out using statistical tables. Table , not filled with numbers , called a layout.
Statistical tables are list , chronological, territorial.
The table has a subject and a predicate. The statistical subject is usually placed on horizontal lines on the left side of the table and reflects the main, main feature. The statistical predicate is placed from left to right along the vertical columns and reflects additional accounting features.
Statistical tables are divided into simple , group and combination.
AT simple tables the numerical distribution of the material according to one attribute is presented , its constituent parts (Table 1). A simple table usually contains a simple list or summary of the totality of the phenomenon under study.
Table 1
Distribution of the dead in the N. hospital by age
AT group tables presents a combination of two signs in connection with each other (Table 2).
table 2
Distribution of the dead in N. hospital by sex and age
AT combin a qi about these tables the distribution of the material according to three or more interrelated features is given (Table 3).
Table 3
Distribution of deaths in N. hospital with different diseases by age and sex
| Diagnosis of the underlying disease | Age | ||||||||||||
| 0-14 | 15-19 | 20-39 | 40-59 | 60 and > | Total | ||||||||
| m | and | m | and | m | and | m | and | m | and | m | and | m+f | |
| Diseases of the circulatory system. | - | - | - | - | |||||||||
| Injury and poisoning | - | - | - | ||||||||||
| malignancy. neoplasms. | - | - | - | - | - | - | |||||||
| Other zab. | - | - | - | - | |||||||||
| Everyone got sick. | - | - |
When compiling tables, certain requirements must be met:
Each table should have a heading that reflects its content;
Within the table, all columns should also have clear, concise titles;
When filling out the table, all cells of the table must contain the corresponding numerical data. The cells of the table remaining blank due to the absence of this combination are crossed out ("-"), and in the absence of information in the cell, "n.s." or "...";
After filling the table in the bottom horizontal row and in the last vertical column on the right, the results of vertical columns and horizontal lines are summed up.
Tables must have a single sequential numbering.
In studies with a small number of observations, summarization is done manually. All accounting documents are decomposed into groups in accordance with the sign code. Next, the data is calculated and recorded in the corresponding cell of the table.
Currently, computers are widely used in sorting and summarizing material. . which allow not only to sort the material according to the studied characteristics , but do the calculations.
Fourth stage- statistical analysis - is a crucial stage of the study. At this stage, the calculation of statistical indicators (frequency , structures , the average size of the phenomenon under study), their graphic representation is given , dynamics , trends, connections between phenomena are established . forecasts are given, etc. The analysis involves the interpretation of the data obtained, the assessment of the reliability of the results of the study. In conclusion, conclusions are drawn.
Fifth stage- Literary processing is final. It involves the finalization of the results of a statistical study. The results can be presented in the form of an article, report, report , dissertations, etc. There are certain requirements for each type of design , which must be observed in the literary processing of the results of a statistical study.
The results of medical and statistical research are being introduced into healthcare practice. Various options for using the results of the study are possible: familiarization with the results of a wide audience of medical and scientific workers; preparation of instructive and methodological documents; formulation of a rationalization proposal and others.
To get an idea about a particular phenomenon, to draw conclusions, it is necessary to conduct a statistical study. The subject of statistical research in health care and medicine can be the health of the population, the organization of medical care, various sections of the activities of medical institutions, environmental factors that affect the state of health.
The methodical sequence of performing a statistical study consists of certain stages.
Stage 1. Drawing up a plan and program of research.
Stage 2. Collection of material (statistical observation).
Stage 3. Material development, statistical grouping and summary
Stage 4. Statistical analysis of the phenomenon under study, formulation of conclusions.
Stage 5 Literary processing and presentation of the results.
Upon completion of the statistical study, recommendations and management decisions are developed, the results of the study are put into practice, and efficiency is evaluated.
In conducting a statistical study, the most important element is the observance of a strict sequence in the implementation of these stages.
First stage statistical research - drawing up a plan and program - is preparatory, at which the purpose and objectives of the study are determined, a plan and research program are drawn up, a program for summarizing statistical material is developed and organizational issues are resolved.
When starting a statistical study, it is necessary to accurately and clearly formulate the purpose and objectives of the study, to study the literature on this topic.
The goal determines the main direction of research and is, as a rule, not only theoretical, but also practical. The goal is formulated clearly, clearly, unambiguously.
To disclose the goal, the research tasks are defined.
An important aspect of the preparatory phase is the development of an organizational plan. The organizational plan of the study provides for the definition of the place (administrative-territorial boundaries of the observation), time (specific terms for the implementation of the observation, development and analysis of the material) and the subject of the study (organizers, performers, methodological and organizational leadership, research funding sources).
Pl a n research d ov a nia includes:
Definition of the object of study (statistical population);
The scope of the study (continuous, non-continuous);
Types (current, one-time);
Ways to collect statistical information. Research program includes:
Definition of the unit of observation;
List of questions (accounting signs) to be registered in relation to each unit of observation*
Development of an individual accounting (registration) form with a list of questions and features to be recorded;
Development of table layouts, in which the results of the study are then entered.
For each unit of observation, a separate form is filled out, it contains a passport part, clearly formulated questions of the program, put in a certain sequence, and the date of filling out the document.
As accounting forms, accounting medical forms used in the practice of medical institutions can be used.
Other medical documents (case histories, and individual cards of an outpatient, the history of the development of the child, the history of childbirth), reporting forms of medical institutions, etc. can serve as sources of information.
To enable the statistical development of data from these documents, the information is copied onto specially designed accounting forms, the content of which is determined in each individual case in accordance with the objectives of the study.
At present, in connection with the machine processing of the results of observation using a computer, program questions can be formalized , when questions in the accounting document are put in the form of alternatives (yes, no) , or ready-made answers are offered, from which a specific answer should be selected.
At the first stage of the statistical study, along with the observation program, a program * of the summary of the data obtained is compiled, which includes the establishment of the principles of grouping, the selection of grouping characteristics , determination of combinations of these signs, drawing up layouts of statistical tables.
Second phase- collection of statistical material (statistical observation) - consists in the registration of individual cases of the phenomenon under study and the accounting signs characterizing them in registration forms. Before and during the performance of this work, instruction (oral or written) of the observers is carried out, and they are provided with registration forms.
In terms of time, statistical observation can be current and one-time.
At current observation Yu denia the phenomenon is studied for some separate period of time (week, quarter , year, etc.) by daily recording of the phenomenon as each case occurs. An example of a current observation is accounting for the number of births , dead, sick , discharged from the hospital, etc. This takes into account rapidly changing phenomena.
At one-time observation Yu denia statistical data are collected at a certain (critical) point in time. One-time observations are: a population census, a study of the physical development of children, accounting for hospital beds for horses of the year, certification of medical institutions, etc. Preventive examinations of the population also belong to this type. One-time registration reflects the state of the phenomenon at the time of study. This type of observation is used to study slowly changing phenomena.
The choice of the type of observation over time is determined by the purpose and objectives of the study. For example, the characteristics of hospitalized patients can be obtained as a result of the current registration of those who left the hospital (current observation) or by a one-day census of patients in the hospital (one-time observation).
Depending on the completeness of the coverage of the phenomenon under study, a continuous and non-continuous study is distinguished.
At continuous The study studies all the units of observation included in the population, i.e. the general population. A continuous study is carried out in order to establish the absolute size of the phenomenon, for example, the total population, the total number of births or deaths, the total number of cases of a particular disease, etc. The continuous method is also used in cases where information is necessary for operational work (accounting for infectious diseases , workload of doctors, etc.)
At discontinuous The study examines only part of the general population. It is divided into several types: questionnaire, monographic, main array, selective. The most common method in medical research is the sampling method.
Monographic method- gives a detailed description of individual units of the population, characteristic in any respect, and a deep, comprehensive description of objects.
Main Array Method- involves the study of those objects in which the vast majority of units of observation are concentrated. The disadvantage of this method is that a part of the population remains uncovered by the study, although small in size, but which can differ significantly from the main array.
Questionnaire method- this is the collection of statistical data using specially designed questionnaires addressed to a certain circle of people. This study is based on the principle of voluntariness, so the return of questionnaires is often incomplete. Often the answers to the questions posed bear the imprint of subjectivity and chance. This method is used to obtain an approximate description of the phenomenon under study.
Sampling method- is reduced to the study of some specially selected part of the units of observation to characterize the entire general population. This method has the advantage of obtaining results with a high degree of reliability as well as a significantly lower cost. The study employs a smaller number of performers , moreover, it requires less time.
In medical statistics, the role and place of the sampling method is especially great, since medical workers usually deal with only a part of the phenomenon under study: they study a group of patients with a particular disease, analyze the work of individual departments and medical institutions , evaluate the quality of certain events, etc.
According to the method of obtaining information in the course of statistical observation and the nature of its implementation, several types are distinguished:
1) direct observation(clinical examination of patients , conducting laboratory , instrumental research , anthropometric measurements, etc.)
2) sociological methods: interview method (face-to-face survey), questioning (correspondence survey - anonymous or non-anonymous), etc .;
3) documentary research a nie(copy of information from accounting and reporting medical documents, information from official statistics of institutions and organizations.)
Third stage- grouping and summary of material - begins with checking and clarifying the number of observations , completeness and correctness of the information received , identifying and eliminating errors, duplicate records, etc.
For the correct development of the material, encryption of primary accounting documents is used. , those. designation of each feature and its group with a sign - alphabetic or numeric. Encryption is a technique , facilitating and accelerating material development , improving the quality, accuracy of development. Ciphers - symbols - are developed arbitrarily. When coding diagnoses, it is recommended to use the international nomenclature and classification of diseases; when coding professions - a dictionary of professions.
The advantage of encryption is that, if necessary, after the end of the main development, you can return to the material for development in order to clarify new relationships and dependencies. Encrypted accounting material makes it easier and faster , than unencrypted. After checking, the features are grouped.
grouping- division of the totality of the studied data into homogeneous , typical groups according to the most significant features. Grouping can be carried out on qualitative and quantitative grounds. The choice of a grouping feature depends on the nature of the studied population and the objectives of the study.
Typological grouping is carried out according to qualitative (descriptive, attributive) features, for example, by gender , profession, disease groups, severity of the course of the disease, postoperative complications, etc.
Grouping by quantitative (variation) features is carried out on the basis of the numerical size of the feature , for example , by age , the duration of the disease, the duration of treatment, etc. Quantitative grouping requires a solution to the question of the size of the grouping interval: the interval can be equal, and in some cases - unequal, even include the so-called open groups.
For example , when grouping by age, open groups can be determined: up to 1 year . 50 years and older.
When determining the number of groups proceed from the purpose and objectives of the study. It is necessary that groupings could reveal the patterns of the phenomenon under study. A large number of groups can lead to excessive crushing of the material, unnecessary detailing. A small number of groups leads to obscuring of characteristic features.
Having finished grouping the material, proceed to the summary.
FROM vodka- generalization of isolated cases , obtained as a result of a statistical study, into certain groups, their calculation and inclusion in the table layouts.
A summary of the statistical material is carried out using statistical tables. Table , not filled with numbers , called a layout.
Statistical tables are list , chronological, territorial.
The table has a subject and a predicate. The statistical subject is usually placed on horizontal lines on the left side of the table and reflects the main, main feature. The statistical predicate is placed from left to right along the vertical columns and reflects additional accounting features.
Statistical tables are divided into simple , group and combination.
AT simple tables the numerical distribution of the material according to one attribute is presented , its constituent parts (Table 1). A simple table usually contains a simple list or summary of the totality of the phenomenon under study.
Table 1
Distribution of the dead in the N. hospital by age
AT group tables presents a combination of two signs in connection with each other (Table 2).
table 2
Distribution of the dead in N. hospital by sex and age
AT combin a qi about these tables the distribution of the material according to three or more interrelated features is given (Table 3).
Table 3
Distribution of deaths in N. hospital with different diseases by age and sex
| Diagnosis of the underlying disease | Age | ||||||||||||
| 0-14 | 15-19 | 20-39 | 40-59 | 60 and > | Total | ||||||||
| m | and | m | and | m | and | m | and | m | and | m | and | m+f | |
| Diseases of the circulatory system. | - | - | - | - | |||||||||
| Injury and poisoning | - | - | - | ||||||||||
| malignancy. neoplasms. | - | - | - | - | - | - | |||||||
| Other zab. | - | - | - | - | |||||||||
| Everyone got sick. | - | - |
When compiling tables, certain requirements must be met:
Each table should have a heading that reflects its content;
Within the table, all columns should also have clear, concise titles;
When filling out the table, all cells of the table must contain the corresponding numerical data. The cells of the table remaining blank due to the absence of this combination are crossed out ("-"), and in the absence of information in the cell, "n.s." or "...";
After filling the table in the bottom horizontal row and in the last vertical column on the right, the results of vertical columns and horizontal lines are summed up.
Tables must have a single sequential numbering.
In studies with a small number of observations, summarization is done manually. All accounting documents are decomposed into groups in accordance with the sign code. Next, the data is calculated and recorded in the corresponding cell of the table.
Currently, computers are widely used in sorting and summarizing material. . which allow not only to sort the material according to the studied characteristics , but do the calculations.
Fourth stage- statistical analysis - is a crucial stage of the study. At this stage, the calculation of statistical indicators (frequency , structures , the average size of the phenomenon under study), their graphic representation is given , dynamics , trends, connections between phenomena are established . forecasts are given, etc. The analysis involves the interpretation of the data obtained, the assessment of the reliability of the results of the study. In conclusion, conclusions are drawn.
Fifth stage- Literary processing is final. It involves the finalization of the results of a statistical study. The results can be presented in the form of an article, report, report , dissertations, etc. There are certain requirements for each type of design , which must be observed in the literary processing of the results of a statistical study.
The results of medical and statistical research are being introduced into healthcare practice. Various options for using the results of the study are possible: familiarization with the results of a wide audience of medical and scientific workers; preparation of instructive and methodological documents; formulation of a rationalization proposal and others.
STATISTICAL VALUES
For a comparative analysis of statistical data, statistical values are used: absolute , relative , medium.
Absolute values
The absolute values obtained in the summary tables during the statistical study reflect the absolute size of the phenomenon (number of health care facilities, number of hospital beds, population , the number of deaths, births, illnesses, etc.). A number of statistical studies ends with obtaining absolute values. In some cases, they can be used to analyze the phenomenon under study. , for example , when studying rare phenomena , if necessary, know the exact absolute size of the phenomenon , if necessary, pay attention to individual cases of the phenomenon under study, etc. With a small number of observations , in the case when it is not required to determine the regularity , absolute numbers can also be used.
In a significant proportion of cases, absolute values cannot be used for comparison with data from other studies. For this, relative and average values are used.
Relative values
Relative values (indicators , coefficients) are obtained as a result of the ratio of one absolute value to another. The most commonly used indicators are: , extensive, ratios , visibility.
Intensive- frequency indicators , intensity, prevalence of the phenomenon in the environment , producing this phenomenon. In health care, morbidity is being studied , mortality , disability, birth rate and other indicators of population health. Wednesday , in which the processes take place is the population as a whole or its individual groups (age, gender, social , professional, etc.). In medical-statistical studies, a phenomenon is, as it were, a product of the environment. For example , population (environment) and sick (phenomenon); sick (environment) and dead (phenomenon), etc.
The value of the base is selected in accordance with the value of the indicator - by 100, 1000, 10000, 100000, depending on this, the indicator is expressed as a percentage , ppm , prodecimille, prosantimille.
The intensive indicator is calculated as follows: for example, in Iran in 1995. 67283 thousand inhabitants lived, 380200 people died during the year.
Intensive indicators can be general and special.
General intensive indicators characterize the phenomenon as a whole . for example , total fertility rates , mortality, morbidity, calculated for the entire population of the administrative territory.
Special intensive indicators (by group) are used to characterize the frequency of the phenomenon in different groups (morbidity by sex, age , mortality among children under 1 year of age , lethality for individual nosological Forms, etc.).
Intensive indicators are used: to determine the level . frequencies , prevalence of the phenomenon; to compare the frequency of the phenomenon in two different populations; for learning changes in the frequency of the phenomenon in dynamics.
extensive- indicators of specific gravity, structure, characterize the distribution of the phenomenon into its constituent parts, its internal structure. Extensive indicators are calculated by the ratio of the part of the phenomenon to the whole and are expressed in percentages or fractions of a unit.
The extensive indicator is calculated as follows: for example, in Greece in 1997 there were 719 hospitals, including 214 general hospitals.
Extensive indicators are used to determine the structure of the phenomenon and a comparative assessment of the ratio of its constituent parts. Extensive indicators are always interconnected, since their sum is always equal to 100 percent: for example, when studying the structure of morbidity, the proportion of an individual disease may increase with its true growth; at the same level, if the number of other diseases has decreased; with a decrease in the number of this disease , if the decrease in the number of other diseases occurs at a faster rate.
Ratios- represent the ratio of two independent, independent of each other , qualitatively different values. Correlation indicators include indicators of the provision of the population with doctors, paramedical workers, hospital beds, etc.
The ratio is calculated as follows: for example, in Lebanon, with a population of 3,789 thousand inhabitants, 3,941 doctors worked in medical institutions in 1996.
visibility- are used for the purpose of a more visual and accessible comparison of statistical values. Visualization metrics provide a convenient way to convert absolute, relative, or average values into an easy-to-compare Form. When calculating these indicators, one of the compared values is equated to 100 (or 1), and the remaining values are recalculated accordingly to this number.
The visibility indicators are calculated as follows: for example, the population of Jordan was: in 1994. - 4275 thousand people, in 1995 - 4440 thousand people , in 1996 - 5439 thousand people.
Visibility indicator: 1994-100%;
| 1995 | = | 4460 *100 | = | 103.9%; |
| 1996 | = | 5439*100 | = | 127.2% |
The visibility indicators indicate by how many percent or how many times there was an increase or decrease in the compared values. Visual indicators are most often used to compare data over time , to present the patterns of the phenomenon under study in a more visual form.
When using relative values, some errors can be made. Here are the most common ones:
1. Sometimes a change in the frequency of a phenomenon is judged on the basis of extensive indicators that characterize the structure of the phenomenon, and not its intensity.
3. When calculating special indicators, you should choose the right denominator for calculating the indicator: for example , the postoperative mortality rate should be calculated in relation to the operated , not all patients.
4. When analyzing indicators, the Time factor should be taken into account:
it is impossible to compare indicators calculated for different periods of time: for example, the incidence rate for a year and for half a year , which can lead to erroneous judgments. 5. It is impossible to compare with each other the general intensive indicators calculated from sets that are heterogeneous in composition, since the heterogeneity of the composition of the medium can affect the value of the indicator.
Average values
Average values give a generalizing characteristic of the statistical population according to a certain changing quantitative attribute.
The average value characterizes the entire series of observations with one number, expressing the general measure of the trait under study. It levels out random deviations of individual observations and gives a typical characteristic of a quantitative trait.
One of the requirements when working with averages is the qualitative homogeneity of the population for which the average is calculated. Only then will it objectively reflect the characteristic features of the phenomenon under study. The second requirement is that the average value only expresses the typical sizes of a trait when it is based on a mass generalization of the studied trait, i.e. calculated on a sufficient number of observations.
Average values are obtained from distribution series (variation series).
Variation series- a number of homogeneous statistical values characterizing the same quantitative accounting attribute, differing from each other in their value and arranged in a certain order (decreasing or increasing).
The elements of the variation series are:
Option- v - numerical value of the studied changing quantitative trait.
Frequency- p (pars) or f (frequency) - the frequency of a variant in a variation series, showing how often one or another variant occurs in this series.
Total number of observations- n (numerus) - sum of all frequencies: n=ΣΡ. If the total number of observations is more than 30, the statistical sample is considered large; if n is less than or equal to 30, it is considered small.
Variational series are discontinuous (discrete), consisting of integers, and continuous, when the values of the variant are expressed as a fractional number. In discontinuous rows, adjacent options differ from each other by an integer, for example: the number of pulse beats, the number of breaths per minute, the number of days of treatment, etc. In continuous series, options can differ by any fractional value of one. Variation series are of three types. Simple- a series in which each option occurs once, i.e. frequencies are equal to one.
O bovine A series in which variants occur more than once.
grouped a ny- row. in which the options are combined into groups according to their size within a certain interval, indicating the frequency of occurrence of all options included in the group.
A grouped variational series is used with a large number of observations and a sick range of extreme values of the variant.
The processing of the variational series consists in obtaining the parameters of the variational series (mean value, standard deviation and average error of the mean value).
Types of averages.
In medical practice, the following averages are most often used: mode, median, arithmetic mean. Less commonly used are other averages: geometric mean (when processing the results of titration of antibodies, toxins, vaccines); root mean square (when determining the average diameter of a section of cells, the results of skin immunological tests); average cubic (to determine the average volume of tumors) and others.
Fashion(Mo) - the value of the trait, most often found in the aggregate. The mode is taken as the variant that corresponds to the largest number of frequencies in the variation series.
Median(Me) - the value of the trait, which occupies the median value in the variation series. It divides the variation series into two equal parts.
The magnitude of the mode and median is not affected by the numerical values of the extreme options available in the variation series. They cannot always accurately characterize the range of variations and are relatively rarely used in medical statistics. The arithmetic mean value characterizes the variation series more accurately.
FROM arithmetic mean(M, or) - is calculated on the basis of all numerical values of the studied trait.
In a simple variational series, where options occur only once, the simple arithmetic mean is calculated using the formula:
Where V - numerical values option,
n - number of observations,
Σ - sum sign
In the usual variational series, the arithmetic weighted average is calculated by the formula:
Where V is the numeric values of the option.
Ρ - frequency of occurrence of the variant.
n is the number of observations.
S - sum sign
An example of calculating the arithmetic weighted average is shown in Table 4.
Table 4
Determination of the average duration of treatment of patients in a specialized department of the hospital
In the example above, the mode is 20 days, since it is repeated more often than others - 29 times. Mo = 20. The serial number of the median is determined by the formula: 
The place of the median falls on the 48th option, the numerical value of which is 20. The arithmetic mean, calculated by the formula, is also 20.
Mean values are important generalizing characteristics of the population. However, individual values of the attribute are hidden behind them. Average values do not show variability, fluctuation of the trait.
If the variation series is more compact, less scattered, and all individual values are located around the average, then the average value gives a more accurate description of this population. If the variation series is stretched, the individual values deviate significantly from the average, i.e. there is a large variability of a quantitative trait, then the average is less typical, worse reflects the entire series as a whole.
Averages of the same magnitude can be obtained from series with different degrees of scattering. So, for example, the average duration of treatment of patients in a specialized department of a hospital will also be 20 if all 95 patients were in hospital for 20 days. Both calculated averages are equal to each other, but obtained from series with varying degrees of variation.
Therefore, to characterize the variation series, in addition to the average value, another characteristic is needed , allowing to estimate the degree of its fluctuation.
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Any statistical study of mass social phenomena includes 3 main stages:
Statistical observation - primary statistical data are formed, or initial statistical information, which is the basis of statistical research. If an error was made in the collection of primary statistical data or the material turned out to be of poor quality, this will affect the correctness and reliability of both theoretical and practical conclusions;
Summarizing and grouping data - at this stage, the population is divided according to the signs of difference and combined according to the signs of similarity, the total indicators for the groups and in general are calculated. Using the grouping method, the studied phenomena are divided into types, groups and subgroups depending on the essential features. The grouping method makes it possible to limit qualitatively essentially homogeneous aggregates, which serves as a prerequisite for the definition and application of generalizing indicators;
Processing and analysis of the obtained data, identification of patterns. At this stage, with the help of generalizing indicators, relative and average values are calculated, a summary assessment of the variation of signs is given, the dynamics of phenomena is characterized, indices and balance constructions are applied, indicators are calculated that characterize the closeness of relationships in changing signs. For the purpose of the most rational and visual presentation of digital material, it is presented in the form of tables and graphs.
Lecture number 2. Statistical observation
1. The concept and forms of statistical observation
Statistical observation is the first stage of any statistical research.
Statistical observation is a scientifically organized work on the collection of massive primary data on the phenomena and processes of social life.
However, not every collection of information is a statistical observation. One can talk about statistical observation only when statistical regularities are studied, i.e. those that appear only in a mass process, in a large number of units of some aggregate.
Therefore, the statistical observation should be:
systematic - to be prepared and carried out according to the developed plan, which includes issues of methodology, organization, technology for collecting information, monitoring the quality of the collected material, its reliability, and the presentation of the final results;
mass - to cover a large number of cases of manifestation of this process, sufficient to obtain truthful statistical data characterizing not only individual units, but the entire population as a whole;
systematic - the study of trends and patterns of socio-economic processes, characterized by quantitative and qualitative changes, is possible only on the basis of systematicity.
The following basic requirements are imposed on statistical observation:
completeness of statistical data (completeness of coverage of units of the studied population, aspects of a particular phenomenon, as well as completeness of coverage over time);
reliability and accuracy of data;
uniformity and comparability of data.
In statistical practice, two organizational forms of observation are used:
1) reporting is such an organizational form in which observation units provide information about their activities in the form of forms of a regulated sample. The peculiarity of reporting is that it is mandatory, documented and legally confirmed by the signature of the head;
2) a special statistical survey, an example of which is the conduct of population censuses, sociological studies, censuses of material remnants, and other observations that are carried out if tasks arise for which there is not enough information to solve. They provide additional material to the reported data or with their help verify the reported data.
The concept of studying the quantitative aspects of objects and phenomena was formed long ago, from the moment a person developed elementary skills in working with information. However, the term "statistics", which has come down to our time, was borrowed much later from the Latin language and comes from the word "status", which means "a certain state of things." “Status” was also used in the meaning of “political state” and was fixed in almost all European languages in this semantic meaning: English “state”, German “Staat”, Italian “stato” and its derivative “statista” - a connoisseur of the state.
The word “statistics” was widely used in the 18th century and was used in the meaning of “state science”. Statistics is a branch of practical activity aimed at collecting, processing, analyzing and providing public use of data on the phenomena and processes of social life.
Analysis is a method of scientific research of an object by considering its individual aspects and components.
Economic-statistical analysis is the development of a methodology based on the widespread use of traditional statistical and mathematical-statistical methods in order to control the adequate reflection of the phenomena and processes under study.
Stages of statistical research. Statistical research takes place in three stages:
- 1) statistical observation;
- 2) summary of received data;
- 3) statistical analysis.
At the first stage, using the method of mass observations, primary statistical data are collected.
At the second stage of the statistical study, the collected data are subjected to primary processing, summary and grouping. The grouping method allows you to select homogeneous populations, divide them into groups and subgroups. Summary - this is the receipt of totals for the population as a whole and its individual groups and subgroups.
The results of grouping and summary are presented in the form of statistical tables. The main content of this stage is the transition from the characteristics of each unit of observation to the summary characteristics of the population as a whole or its groups.
At the third stage, the obtained summary data are analyzed by the method of generalizing indicators (absolute, relative and average values, variation indicators, index systems, methods of mathematical statistics, tabular method, graphical method, etc.).
Fundamentals of statistical analysis:
- 1) assertion of facts and establishment of their assessment;
- 2) identification of characteristic features and causes of the phenomenon;
- 3) comparison of the phenomenon with normative, planned and other phenomena, which are taken as the basis for comparison;
- 4) formulation of conclusions, forecasts, assumptions and hypotheses;
- 5) statistical verification of the proposed assumptions (hypotheses).
Analysis and generalization of statistical data is the final stage of statistical research, the ultimate goal of which is to obtain theoretical conclusions and practical conclusions about the trends and patterns of the studied socio-economic phenomena and processes. The tasks of statistical analysis are: determination and evaluation of the specifics and features of the phenomena and processes under study, the study of their structure, interrelations and patterns of their development.
Statistical analysis of data is carried out in close connection with the theoretical, qualitative analysis of the essence of the phenomena under study and the corresponding quantitative tools, the study of their structure, relationships and dynamics.
Statistical analysis is a study of the characteristic features of the structure, connection of phenomena, trends, patterns of development of socio-economic phenomena, for which specific economic-statistical and mathematical-statistical methods are used. Statistical analysis is completed by the interpretation of the obtained results.
In statistical analysis, signs are divided according to the nature of their influence on each other:
- 1. Sign-result - the sign analyzed in this study. The individual dimensions of such a feature in individual elements of the population are influenced by one or more other features. In other words, the attribute-result is considered as a consequence of the interaction of other factors;
- 2. Sign-factor - a sign that influences the studied sign (feature-result). Moreover, the relationship between the sign-factor and the sign-result can be quantitatively determined. Synonyms of this term in statistics are "factor sign", "factor". It is necessary to distinguish between the concepts of a sign-factor and a sign-weight. A sign-weight is a sign that must be taken into account in the calculations. But, the sign-weight does not affect the studied sign. A feature-factor can be considered as a feature-weight, i.e., taken into account in the calculations, but not every feature-weight is a feature-factor. For example, when studying in a group of students the relationship between the time of preparing for an exam and the number of points obtained in the exam, the third attribute should also be taken into account: "The number of people certified for a certain score." The last feature is not influencing the result, however, will be included in the analytical calculations. It is this trait that is called the weight trait, and not the factor trait.
Before proceeding with the analysis, it is necessary to check whether the conditions that ensure its reliability and correctness are met:
- - Reliability of primary digital data;
- - Completeness of coverage of the studied population;
- - Comparability of indicators (accounting units, territory, calculation method).
The main concepts of statistical analysis are:
- 1. Hypothesis;
- 2. Decisive function and decisive rule;
- 3. Sample from the general population;
- 4. Assessment of the characteristics of the general population;
- 5. Confidence interval;
- 6. trend;
- 7. Statistical relationship.
Analysis is the final stage of statistical research, the essence of which is the identification of relationships and patterns of the phenomenon under study, the formulation of conclusions and proposals.
Statistical research requires special training to conduct it at a high scientific level.
Statistical study- this is a scientific and organizational process in which a single program is monitored for certain phenomena and processes, the collection, registration of primary data, their processing and analysis.
Any research begins with taking into account the facts and collecting primary material, which, depending on the purpose and task of the work, can be versatile in meaning and methods of obtaining. For example, population censuses are needed to study the size and composition of the population. To study the spread of diseases, it is necessary to record and register individual diseases in medical institutions. It is possible to obtain systematic information about the activities of medical institutions only if they organize the proper type of relevant data. Therefore, the task of statistical research is to collect objective, reliable and complete basic information.
The process of statistical research can be divided into stages:
Drawing up a plan for statistical research, developing its program;
Registration and collection of statistical material;
Development and summary of data;
Statistical analysis;
Implementation of research results into practice.
Plan and program of statistical research
Statistical research is always carried out according to a specific plan, which includes both programs and organizational issues, and is determined by the task of statistical observation, which should provide a complete and versatile description of the phenomenon under study. Thus, the preparation of a research plan involves the solution of a number of organizational issues that lie in the formation of the goal, objectives of the study, the choice of the object and unit of observation, the place and time of the study, the source of information, the form of practical implementation, as well as methods of statistical research.
Target statistical research answers the question "why study?".
It foresees the determination of the patterns inherent in the phenomenon and the connections of this phenomenon with others, the development of measures to reduce the impact of negative factors on health, the implementation of the results of work in the practice of health protection and measures aimed at improving the quality of medical care.
A task answers the question "what to do?".
So, for example, the task of a statistical study may be to study the level and structure of the phenomenon (morbidity, mortality) in certain population groups, the frequency of the phenomenon in groups that are influenced by various factors (environment, biological and social), the volume and quality of medical care for certain groups population.
When preparing an observation, in addition to the goal, it is necessary to determine what exactly is to be examined - to establish it an object, namely, a statistical set of persons or phenomena, which consists of units, facts that are to be studied. So, for example, it can be a set of individuals (sick, dead), functional units (beds in a hospital, hospital), contingents that are characterized by certain phenomena (incapacitated workers), etc.
The object of statistical observation must have the boundaries of the population designated for study. For example, before conducting a statistical study, the activities of medical institutions must be determined, the activities of which institutions will be studied. They are regulated by the objectives of the study.
When studying the spread of diseases and mortality of the population, it is also necessary to outline the boundaries of this population, among which groups of the population this phenomenon should be studied. If the object and boundaries of the study are not precisely defined, then the data obtained will not give a complete understanding of the level and composition of the phenomenon.
When conducting a population census, the object of observation will be the totality of persons who permanently reside in a certain territory. At the same time, it is important to know who to enumerate: the population that actually lives in a given territory at the time of the census, or who lives permanently. Thus, it is important to know data on the size of the actual population for the organization of various types of services, including medical services, and the population that lives permanently - to determine the composition of different contingents (for example, children of preschool or school age to determine the availability of their schools and childcare facilities) . Thus, the choice and purpose of the object depends on the purpose and objectives of the statistical study.
Simultaneously with the definition of the object, it is necessary to assign a unit of observation. An observation unit (accounting unit) is an integral part of the statistical population (an individual, an individual phenomenon), an integral element of an object that has characteristics that are subject to registration and study (gender, age, birth weight, length of service, result of treatment, time spent in hospital). hospital, etc.). It must be clearly defined: so in the study of diseases, the unit of observation can be like a sick person. So is a certain disease, depending on the tasks and objectives of the study.
When studying diseases according to the data of applications to outpatient clinics, only the initial visit is taken as the unit of observation. When determining the number of newborns, only living ones are taken into account.
However, sometimes there are special instructions for choosing units of observation. So, for example, the concept of dead birth is determined by special rules that define the terms "born alive and dead", or "born dead". The quality of the obtained materials and the possibility of their use for analysis depend on the correct choice of the research unit.
When creating plans for statistical research, not only the forms of accounting documents and the rules for filling them out are worked out, but also the questions of who will fill them out, control the correctness and completeness of the collected data, as well as other organizational and methodological issues related to the collection of statistical materials. Thus, at the first stage, executors are appointed, and the budget is approved.
Research methods (types).
Depending on the nature of the observation in time, there are current, periodic and one-time observations.
If the collection of material is carried out systematically, with constant registration of facts as they appear, then this will current observation.
If it is done regularly, but not constantly, then it will periodical observation.
Current statistical study- this is the identification of phenomena that change rapidly over time and are a continuous process that requires ongoing registration. This method determines the incidence of individual groups, the birth rate, the death rate of the population, etc.
One-time observations reflect the state of the phenomenon at a certain point in time, which is called the critical moment of observation. An example would be a population census or a census of people who went to a polyclinic at a certain point in time, a census of places, health care institutions, the timing of the work of doctors or paramedical workers, etc. Such observations show the statics of phenomena, the change of which over time is relatively free, If necessary, a combination of both forms of statistical research is used. Thus, data on the number and structure of health care institutions are collected using a one-time method, and on their activities - through current accounting.
From the point of view of the sufficiency (completeness) of taking into account the facts of observation, statistical studies are divided into: continuous (solid) and discontinuous (not continuous) (partial).
Continuous (continuous) research cover all units of observation that are part of the population under study (the main population). This is necessary if it is necessary to establish the absolute dimensions of phenomena (population, number of places with AIDS, etc.). Conducting such a study is a very cumbersome, economically unprofitable method that requires significant costs. The development of the material, of course, will require a lot of time, although, at first glance, the method is the most likely,
If a continuous observation is impossible or incomplete, then it is necessary to carry out discontinuous. It will not require a full account of all units of the population, but will be content with a certain part. When studying this part, it is also possible for the material to obtain generalizing conclusions, which with sufficient probability can be extended to the entire set.
Discontinuous research can be monographic, main array, selective.
monographic the description is used for a detailed, in-depth characterization of typical units of the population, for studying the development of an institution, the reasons that contribute to its success or cause shortcomings. A detailed description of the work of some typical or advanced medical institutions is important for the socialization and formation of elements of excellence and its dissemination.
Method usage main array allows you to study objects that concentrate more units of observation. For example, if it is known that the bulk of tuberculosis patients (80-90%) are treated at two specialized clinics in the city, then studies of the organization of medical care for these contingents are carried out in these hospitals. The shortcomings of the method are that some of the patients remain unexplored, and the results may differ from those obtained from the main array.
Selective called a study in which the characteristics of the entire set of facts are given according to some part of it, which is selected randomly or by certain criteria.
Sampling method, as one of the types discontinuous research is possible provided that the sample is representative of the main one in quantitative and qualitative terms, i.e., that the sufficiency of the number of cases to be taken into account is determined, and all the versatility of the phenomenon under study is created in the sample. In such a case, the results can be extended to the main population.
Representativeness sample group is achieved by the correct selection of units of observation. It is important that each unit of the entire population had the same opportunity to get into the sample population. In addition, its qualitative characteristics are important, which can be ensured typological choice method. Its essence lies in the fact that the entire population is divided into several groups of the same type, from which units of observation are selected. So, for example, when studying diseases of the urban population, it is necessary to single out territorial units (districts). In typologically displayed groups, the choice of units of observation can be made proportionally or disproportionately, according to the size of each group.
The choice of units of observation can be carried out by methods:
Random selection- draw, lottery, random selection, etc.;
Mechanical selection- according to a certain size of the population by a reliable principle (every fifth, tenth, etc.);
nesting- nests (groups) are formed from all sets, the most typical objects that are studied by a continuous or selective method;
Directed Choice, which consists in the fact that persons with the same experience, age or gender are selected, etc.
Often in sample statistical studies, complex methods of selection are used that provide a high probability of results.
Selective studies require less time, personnel, funds, they can have an in-depth program, which is an advantage over continuous research. The sample set will always differ from the main (general, exhaustive). However, there are methods that allow you to establish the degree of discrepancy between their quantitative characteristics and the boundaries of possible fluctuations in indicators for a given number of observations.
Sample size, i.e. the probability of the number of observation units for different selection methods is calculated differently. The main formulas are shown in Table 1.
Table 1.
Required sample size for some array generation methods
Legend:
n - required sample size;
σ - standard deviation (feature variability);
N- the size of the general population;
T - reliability criterion;
W- evaluation of the part;
∆ - marginal error.
The number of observations in this case plays an important role, the larger the number of observations, the more accurately the main population is displayed and the smaller the size of the probabilistic error. The methods presented allow us to select the necessary volume of observations for study with a sufficient degree of probability.
The repeated or non-repeated choice is determined by the possibility of multiple or single participation in the formation of sample groups of each of the observation units.
Thus, the selective method, with its proper organization and conduct, is the most perfect form intermittent observation.
Methods for recording and collecting medical and statistical information
In a statistical study, various methods can be used:
questioning;
Direct registration;
documentary accounting;
copying;
At direct accounting facts, the necessary statistical data are obtained by special accounting - inspection, measurement, weighing and recording on an individual observation card.
Documentary accounting as primary is based on the systematic registration of facts, for example, in medical institutions. Such data from various official documents are copied into the map for study.
copying data in the developed statistical document can be used, for example, to obtain information on the composition of persons seeking medical care, on the medical institutions themselves, their activities, personnel and other issues, respectively, of development programs.
The use of technical methods of accounting for medical information, its centralization optimizes the mechanism for its further processing and analysis.
The collection of medical and statistical information through a survey is carried out by expeditionary or correspondent methods, self-registration.
At forwarding method the researcher interrogates the patient and, from his words, independently fills out the research card, which ensures control over the correctness of the answers.
At self-registration the examined patient independently fills out the card.
At correspondent method the researcher sends out cards for examination with appropriate instructions for filling them out. Having completed cards (with answers to questions), the respondent sends them to the address of the researcher.
Questionnaire method used when it is impossible to directly observe the phenomenon under study. Questionnaires are sent to specific individuals, but their answers are incomplete and inaccurate. The disadvantage of this method is that the correctness of filling out the questionnaires depends on the understanding of the formulated questions.
That's why questionnaire method used as an auxiliary or in the absence of more reliable methods of obtaining data. Often it is useful in sociological research.
The choice of survey methods is determined by the tasks and the monitoring program. The most reliable is the forwarding one, but it requires the most expenses. The self-registration method is less expensive, therefore it is used when it is possible to fill out the cards by the examined persons. This method is often used in censuses. The correspondent method requires the least cost, but the data obtained with its help is not always reliable. It can be used as an auxiliary, taking into account its subjectivity, inaccuracy.
Simultaneously with the development of methods for collecting material, preparations are being made for grouping and combining data,
Grouping in statistics is the division of population units into homogeneous parts with their inherent characteristics. Its tasks are to separate the studied facts into separate qualitative homogeneous parts, which is a necessary condition for determining generalizing indicators.
The plan of statistical research should provide for the groups into which the phenomenon should be divided. The significance of such a division of the population into qualitatively homogeneous groups lies in the need to show their peculiarity, connection with others, and mutual dependence. So, when studying the incidence of nosological forms, patients in these groups are qualitatively heterogeneous: children, youth, elderly people, therefore, each group of diseases must be divided into even more homogeneous ones - by sex, age, etc.
The principle of grouping statistical material should be determined by a doctor who is well aware of its methodological basis. The features of the population units that underlie the grouping are called grouped. They are variable (quantitative) and are quantified. Variable grouping is carried out according to the numerical values of the signs (grouping of patients by age, time of illness, stay in bed, children by body weight, height, etc.).
Qualitatively defined features are called attributive: division of patients by disease groups, population by sex, professions, etc.
When grouping by attributive features that do not have a quantitative expression, the number of groups is determined by the feature itself (gender, profession, disease).
When conducting statistical grouping, it is possible to divide a qualitatively homogeneous group (men) into age groups (according to variable characteristics) - this will be a combined grouping.
The choice of group features is based on three basic rules:
the grouping should be based on the most significant features that meet the objectives of the study;
when choosing group characteristics, it is necessary to take into account the specific conditions in which this phenomenon is realized;
when studying a phenomenon that is influenced by several different factors, grouping must be carried out not according to one, but several signs (combined).
Grouping is the basis for combining statistical material and, given the understanding of all the rules, allows you to draw the right conclusions and identify reliable patterns that are inherent in the population under study.
Grouping must be distinguished from classification, which is based on the division of phenomena and objects into certain groups, classes based on their typicality and difference. A qualitative sign is the basis of classification. Classifications are standard and unchanged over a long period of time, are determined and adjusted by state and international statistics authorities. Classifications are the same for any study and often form the basis of groupings.
At the first stage, programs for statistical observation, development and integration of statistical material, data analysis are developed.
The observation program is a list of signs recorded in the accounting document that characterize each unit of observation. It must meet the following requirements: it must contain a list of only essential features that reflect the phenomenon under study, its type, features and property; wording accuracy and logical order.
Questions about the studied characteristics are resolved after the appointment of the unit, taking into account the objectives of the study. So, in the study of diseases, program features can be gender, age, bad habits, date of seeking medical help, work experience, place of work, etc.
Of great importance is the formulation of program issues, their clarity and unambiguous interpretation. They can be presented in the form of closed questions - alternative (yes, no), or with a choice of three or more answers. To an open question (“Tell me your comments about the work of the department?”), the respondent can give any answer.
To ensure unambiguous data that is recorded for each observation unit, the observation program is documented in the form of a record document. When conducting a statistical study, the sources of information may be official accounting or specially developed accounting documents.
If the research program does not go beyond the boundaries of existing official reporting and accounting documents (statistical coupon for registering the final diagnosis, medical death certificate, outpatient coupon, etc.), then after being developed for writing a report of a medical institution, they can be used for applied statistical research.
If the research program requires the receipt of materials that are not in official records, a special record is developed. It may take the form of a form, questionnaire, card, or be recorded in a computer database. Signs are entered on a map or in a computer database, which are recorded for each unit of observation: data of one newborn or deceased, one patient, etc. The list documents (journal, statement, account book) contain data from two or more units of observation, which are located in separate his ranks. Individual account documents may have more questions than list documents. Therefore, with card or computer forms of accumulation of material, its integration is facilitated, and the development is carried out with a more in-depth program.
Development program (associations) - addition of table layouts.
The association can be centralized - all primary materials are sent for processing to one analytical center, decentralized - processing is carried out locally.
The aggregation is carried out in the form of statistical tables, which are filled with the data of the combined statistical materials. The received statistical data should be checked beforehand.
Statistical tables is a form of systematic, rational and visual presentation of digital material that characterizes the studied phenomena and processes.
The table has a common title at the top. It briefly indicates its essence, time and place of obtaining data. The statistical table should also have data on the numerical measurement of the phenomenon under study (%, abs. numbers, etc.) and the calculated totals of the studied features.
The statistical table has a subject and a predicate. The object of study is called the subject. This might be unit of the statistical population, or their groups (diagnoses, types of diseases of the population by age groups, etc.). The predicate of the statistical table can be a list of quantitative indicators that characterize the object of study, that is, the subject of the table. The names of units or groups (subject) are made on the left of the table, and the name of the predicate in the headings is a graph. In the upper part, above the table heading, their numbering is given (table 1,2,3...).
The statistical subject is divided by horizontal lines into glades, the statistical predicate - by vertical lines into graphs. The intersections of horizontal and vertical lines form cells in which digital data is recorded. Horizontal rows and vertical columns of numbers, and their result must have the same number in the cell in the rows of predicates. In the names of tables, rows and columns indicate the unit of measurement.
Table layouts can be developed, when data are given separately for each feature. Then, based on them, they are formed analytical tables, which generally presents data on group characteristics.
There are the following types of statistical tables: simple, group, combined.
simple table- numerical distribution of data on one attribute,
There are no groupings in such a table; it does not characterize the relationship between features. A simple table provides little information, although it is clear and fast for analysis. An example of a simple table can be Table 2.
