MMedical edical statisticsstatistics

The medical statistics is a science The medical statistics is a science which studies health of the which studies health of the

population depending on social, population depending on social, economic, cultural, sanitary-hygienic, economic, cultural, sanitary-hygienic, medical and biologic factors and has medical and biologic factors and has a goal of establishing tendencies of a goal of establishing tendencies of these dependences in conditions of these dependences in conditions of

activity of system medical care.activity of system medical care.

The medical statistics studies:The medical statistics studies:

1.0 Health of the population:1.0 Health of the population:

1.1 Demographic processes;1.1 Demographic processes;

1.2 Morbidity;1.2 Morbidity;

1.3 Invalidity ;1.3 Invalidity ;

1.4 Somatometry and determining of 1.4 Somatometry and determining of biochemical constants; biochemical constants;

1.5 Mental health and psychometry.1.5 Mental health and psychometry.

2.0 Conditions of an environment and people’s life 2.0 Conditions of an environment and people’s life styles:styles:2.1 Air;2.1 Air;2.2 Water;2.2 Water;2.3 Radiation;2.3 Radiation;2.4 Nutrition;2.4 Nutrition;2.5 Material welfare;2.5 Material welfare;2.6 Work and training;2.6 Work and training;2.7 Rest;2.7 Rest;2.8 Behavior.2.8 Behavior.

3.0 Medical base:3.0 Medical base:

3.1 Medical establishments ;3.1 Medical establishments ;

3.2 Health manpower ;3.2 Health manpower ;

3.3 The budget of public health services.3.3 The budget of public health services.

4.0 Activity of system of public health 4.0 Activity of system of public health services:services:

4.1 Ambulatory and polyclinics;4.1 Ambulatory and polyclinics;

4.2 Hospitals;4.2 Hospitals;

4.3 Drugstores;4.3 Drugstores;

4.4 Social - medical activity.4.4 Social - medical activity.

The ways of formation of The ways of formation of statistical integrity :statistical integrity :

1.0 By volume1.0 By volume

2.0 By time2.0 By time

3.0 By type3.0 By type

The plan and program of medico-The plan and program of medico-statistical research includesstatistical research includes::

1.0 Data collection:1.0 Data collection:

1.1 A concentration and preservation of the 1.1 A concentration and preservation of the data;data;

1.2 Data transmission.1.2 Data transmission.

2.0 Data processing:2.0 Data processing:2.1 Normalization (standardization) of the 2.1 Normalization (standardization) of the

data;data; 2.2 Coding and grouping of the data;2.2 Coding and grouping of the data; 2.3 Registration;2.3 Registration;

2.4 Calculation of average values, dispersions, 2.4 Calculation of average values, dispersions, errors;errors; 2.5 Comparison, definition of a difference;2.5 Comparison, definition of a difference; 2.6 Correlation, regress, complex estimations.2.6 Correlation, regress, complex estimations.

3.0 The analysis of the data:3.0 The analysis of the data:3.1 Survey, interpretation analysis;3.1 Survey, interpretation analysis;3.2 The mathematical analysis: disperse, 3.2 The mathematical analysis: disperse,

multifactor, initial, logistic, system, etc.multifactor, initial, logistic, system, etc.

Registration and accounting medical Registration and accounting medical documents can serve as programs of documents can serve as programs of medic-statistical research .medic-statistical research .

Medical-statistical research can be complete Medical-statistical research can be complete or selective.or selective.

Complete Complete or continuous research covers all or continuous research covers all observation units.observation units.

SelectiveSelective research covers a representative research covers a representative part of the supervision units, which enables part of the supervision units, which enables to evaluate phenomenon in whole.to evaluate phenomenon in whole.

Research is of great importance. The Research is of great importance. The territory strongly influences the results of territory strongly influences the results of research.research.

The next question isThe next question is time time and and term term of the of the research. Research can lastresearch. Research can last constantly constantly,, that that is to be current, to be carried outis to be current, to be carried out periodicallyperiodically, during certain time or to be, during certain time or to be one- one-stage.stage.

Constant researches are: studying of natural Constant researches are: studying of natural movement of the population, periodic — movement of the population, periodic — studying of prevalence of chronic diseases, studying of prevalence of chronic diseases, one-stage — population census, fixing of a one-stage — population census, fixing of a condition of medical servicecondition of medical service

After gathering the statistical data is beingAfter gathering the statistical data is being processedprocessed. This process includes . This process includes quantitative and qualitative check, coding quantitative and qualitative check, coding and grouping of these data. Quantitative and grouping of these data. Quantitative check means check of correctness of check means check of correctness of statistical record of documents, qualitative statistical record of documents, qualitative — logic comparison of the data, for — logic comparison of the data, for example, age and the diagnosis, age and example, age and the diagnosis, age and employment, growth and weight of a body, employment, growth and weight of a body, etc. Later there is coding. To each etc. Later there is coding. To each quantitative or qualitative characteristic of quantitative or qualitative characteristic of the phenomenon certain code is given.the phenomenon certain code is given.

Grouping may be a distribution of the data Grouping may be a distribution of the data according to quantitative or qualitative according to quantitative or qualitative characteristics with the purpose of their analysischaracteristics with the purpose of their analysis

Variable — is a quantitative or qualitative values of Variable — is a quantitative or qualitative values of the concrete characteristic of the phenomenon, for the concrete characteristic of the phenomenon, for example, newborn can have length of a body 47, example, newborn can have length of a body 47, 48, 49, 50, etc48, 49, 50, etc

An absolute value — the number which An absolute value — the number which characterizes the phenomenon in its absolute characterizes the phenomenon in its absolute (arithmetic) value.(arithmetic) value.

A relative value — a number which characterizes A relative value — a number which characterizes the relation of one value to another and can mean the relation of one value to another and can mean a part, frequency or a ratio of one number to a part, frequency or a ratio of one number to another. An absolute value — the number which another. An absolute value — the number which characterizes the phenomenon in its absolute characterizes the phenomenon in its absolute (arithmetic) value.(arithmetic) value.

Table 2.1 A variation line

Weight of newborns, gr.Number of

newborns, n

2900 1

3000 2

3100 3

3200 3

3300 2

3400 1

The range is the difference between The range is the difference between the highest and lowest values in a the highest and lowest values in a

series.series.

1.The range is used to measure data 1.The range is used to measure data spread.spread.

2.The range provides no information 2.The range provides no information concerning the scatter within the series.concerning the scatter within the series.

Statistical totality will consist of elements, which Statistical totality will consist of elements, which have identical characteristics and represent an have identical characteristics and represent an object of the statistical analysis. For example, in object of the statistical analysis. For example, in research of demographic problems of the country research of demographic problems of the country by statistical set there will be all of its population; by statistical set there will be all of its population; in research of the stationary aid — hospitalized in research of the stationary aid — hospitalized patients.patients.

General statistical totality includes all elements of General statistical totality includes all elements of research.research.

Selective statistical totality contains a part of Selective statistical totality contains a part of general totality, which represents all of its general totality, which represents all of its elements. It should to be selected from general elements. It should to be selected from general statistical set to give the same chance to get in statistical set to give the same chance to get in sample to each statistical unit.sample to each statistical unit.

Statistical unit (unit supervision) submitted by an Statistical unit (unit supervision) submitted by an element of which there is a statistical set (for element of which there is a statistical set (for example, a person, a family, a newborn, a example, a person, a family, a newborn, a pregnant woman, a patient withpregnant woman, a patient with ischemic heart ischemic heart disease , etc.disease , etc.

Statistical attribute is a general property for all Statistical attribute is a general property for all units, which is studied during statistical research, units, which is studied during statistical research, for example, studying of weight, growth, disease for example, studying of weight, growth, disease in newborn etc.in newborn etc.

Statistical index is the statistical value which Statistical index is the statistical value which makes it possible to characterize the makes it possible to characterize the phenomenon.phenomenon.

Processing the statistical data and the formation of Processing the statistical data and the formation of statistical tables allows understanding the statistical tables allows understanding the researched phenomena better.researched phenomena better.

Statistical tables are breadboard models, Statistical tables are breadboard models, which will consist of columns and lines on which will consist of columns and lines on which crossing statistics data are placed.which crossing statistics data are placed.

There are simple, group and combined There are simple, group and combined tables.tables.

Table 2.2Table 2.2Number of medical establishments in the Number of medical establishments in the

area (the simple table)area (the simple table)

Medical establishmentsNumber of

establishments

District hospitals 75

Areal hospitals 1

Regional hospitals 20

Total 96

Table 2.3 Table 2.3 Territorial distribution of medical Territorial distribution of medical establishments in the area (the group table)establishments in the area (the group table)

Medical establishments

North Center South Total

District hospitals

20 40 15 75

Regional hospitals

5 12 3 20

Areal hospitals

- 1 - 1

Total 25 53 18 96

The average value characterizes the phenomenon The average value characterizes the phenomenon in one way. It is much more frequently applied in in one way. It is much more frequently applied in the statistical analysis — an average term of stay the statistical analysis — an average term of stay of the patient in bed, average spaciousness of of the patient in bed, average spaciousness of hospitals, etc.hospitals, etc.

The dispersion from average value shows The dispersion from average value shows variability (fluctuation) of an individual cases in variability (fluctuation) of an individual cases in relation to average value.relation to average value.

The average error displays the relation of the The average error displays the relation of the statistics received at selective research, to a statistics received at selective research, to a parameter of continuous or complete research.parameter of continuous or complete research.

Parameters of correlation and regress are used for Parameters of correlation and regress are used for definition of functional, causal relationships definition of functional, causal relationships between two or more characteristics.between two or more characteristics.

Extensive parameters characterize the Extensive parameters characterize the structure of statistical totality .structure of statistical totality .

Intensive parameters display frequency of Intensive parameters display frequency of the phenomenon in the environment, the phenomenon in the environment, indicate its level.indicate its level.

Relative and average values and Relative and average values and their reliabilitytheir reliability

In medical statistics themselves the following In medical statistics themselves the following kinds of relative parameters are used:kinds of relative parameters are used:

Extensive;Extensive; Intensive;Intensive; Relative intensity;Relative intensity; Visualization ;Visualization ; CorrelationCorrelation

The extensive parameterThe extensive parameter or a parameter of or a parameter of distribution characterizes a parts of the distribution characterizes a parts of the phenomena (structure), that is it shows, what part phenomena (structure), that is it shows, what part from the general number of all diseases (died) is from the general number of all diseases (died) is made with this or that disease which enters into made with this or that disease which enters into total.total.

The general formula of its subtraction is the The general formula of its subtraction is the following: following:

part × 100part × 100common numbercommon number

The intensive parameterThe intensive parameter characterizes characterizes frequency or distribution. It shows, how frequency or distribution. It shows, how frequently the given phenomenon occurs in frequently the given phenomenon occurs in the given environment.the given environment.

General formula of the calculation is the General formula of the calculation is the following:following:

phenomenon ×100(1000;10 000;100 000)phenomenon ×100(1000;10 000;100 000) environment environment

ParametersParameters of relative intensity of relative intensity represent a represent a numerical ratio of two or several structures numerical ratio of two or several structures of the same elements of a set, which is of the same elements of a set, which is studied.studied.

The parameter of visualization The parameter of visualization characterizes characterizes the relation of any of comparable values to the relation of any of comparable values to the initial level accepted for 100.the initial level accepted for 100.

The parameter of correlation The parameter of correlation characterizes characterizes the relation between diverse values. the relation between diverse values.

General formula of the calculation is the General formula of the calculation is the following:following:

phenomenon ×100(1000;10 000;100 000)phenomenon ×100(1000;10 000;100 000) environment environment (which doesn’t produces this (which doesn’t produces this

phenomenon)phenomenon)

Dynamic linesDynamic lines

are the lines, which one consists are the lines, which one consists from homogeneous of values, from homogeneous of values, which one characterize change which one characterize change any one appearances for a any one appearances for a definite span.definite span.

Dynamic analysisDynamic analysis

Pure gainPure gain - a difference between - a difference between following and previous numbers of following and previous numbers of dynamic lines.dynamic lines.

Rate of gainRate of gain - the relation of the pure - the relation of the pure gain to previous numbergain to previous number increased on increased on 100 %.100 %.

Rate of growthRate of growth - the relation of - the relation of following and previous numbers of following and previous numbers of dynamic linesdynamic lines increased on 100 %.increased on 100 %.

Average valuesAverage values are parameters of the basic are parameters of the basic quality of the phenomena which are studied, quality of the phenomena which are studied, or a unit of measurements of the central or a unit of measurements of the central tendency of distribution a variant.tendency of distribution a variant.

In all researches which concern a state of In all researches which concern a state of health, the great value has comparison of health, the great value has comparison of the phenomenon with the standard as which the phenomenon with the standard as which the average value acts.the average value acts.

Average simple arithmeticAverage simple arithmetic is is determined according to the determined according to the

model:model:

NXMa

Average mixed arithmeticAverage mixed arithmetic is is determined according to the model:determined according to the model:

n

nXзM

ModeMode or dominant – is a variant, which or dominant – is a variant, which occurs in a variation line with the greatest occurs in a variation line with the greatest frequency.frequency.

MedianMedian - is a variant ,which occupies - is a variant ,which occupies median position. In a case if number of the median position. In a case if number of the variant is pair, the median represents variant is pair, the median represents average value of two variant ,which occupy average value of two variant ,which occupy median position.median position.

Average valuesAverage values

1. Arithmetical mean 1. Arithmetical mean (M)(M)

--

is generalized value, which is generalized value, which gives characteristics by one gives characteristics by one of the number for of the number for occurrence, that may have occurrence, that may have many an individual many an individual manifestationsmanifestations

2. Moda (Module) 2. Moda (Module) (Mo)(Mo) --

is a value of the feature, is a value of the feature, which is founded in totality which is founded in totality most frequentlymost frequently

3. Median 3. Median

(Me)(Me)--

is a value of the feature, is a value of the feature, which occupies medium which occupies medium position in variation line and position in variation line and divides it in two symmetrical divides it in two symmetrical partsparts

The methods of determination of The methods of determination of arithmetical meanarithmetical mean

1. Simple arithmetical 1. Simple arithmetical

meanmean is calculated when variants are is calculated when variants are met with equal frequency and met with equal frequency and quantity of observations (n) is ≤ quantity of observations (n) is ≤ 3030

2. Weight arithmetical 2. Weight arithmetical

meanmean is calculated when variants are is calculated when variants are met with different frequency and n met with different frequency and n

is >30is >30

3. Method of moments 3. Method of moments is calculated when variants are is calculated when variants are expressed by great numbers and expressed by great numbers and quantity of observations is quantity of observations is expressed by hundreds and expressed by hundreds and thousands of incidentsthousands of incidents

n

VM

n

VPM

in

dpAM *

Properties of arithmetical meanProperties of arithmetical mean

1. It occupies an average position in 1. It occupies an average position in variation linevariation line

2. It has abstract character2. It has abstract character

3. Sum of deflection of all variants from 3. Sum of deflection of all variants from medium value is equal to 0medium value is equal to 0

Thank you!