Ministry of Health of the Republic of Uzbekistan 
Tashkent Medical Academy 

                                                                                                                                        "Approved"
   Pro-Rector
prof. Sh.A.Boymurodov 

                                                                                                «-------»--------- 2017. 

Department: "Public health organizations and health management"
Subject: Social Care and Health Organization.
"Biostatistics"
Subject:
"Standardization and its application in statistical analysis"

Educational - methodical development
(For teachers and students of 3 rd year medical - pedagogical, medical faculty)

Tashkent 2017

Compiled by:

Rustamov H.E. - MD Professor: "Public health organizations and health management"
Hvan A.A. - Assistent: "Public health organizations and health management"

Reviewers:

Head. Department of "Public health organizations and health care management" Tash.PMI, prof. Iskandarov Sh.T.
Professor, Department of General and Radiation Hygiene "TMA
Tajibayeva NS

The main issue in this topic: 
Method of standardization and conditions of use. 
Standardization methods 
Terms of use and the stages of the direct method of standardization. 
Analysis of standardized indicators. 

Questions for controlling the initial level of knowledge of students: 
What is standardization? 
What are my standards? 
Conditions for applying the direct method of standardization. 
Stages of the direct method of standardization. 
Why expect special intense performance in the comparative groups? 
The choice of standard and its calculation. 
The content of Phase III standardization? 
As evidenced by standardized indicators and their calculation? 

Theme sessions "Standardization and its application in statistical analysis" 
1st place for lessons, equipment: 
Department 
Handout 
Typical tasks 
Calculators 
2. 1. The duration of the study subjects: 2 hours
 3. Session Purpose:: Students must learn standardized methods of calculation and to seize their practical application 

4. Po graduation a student must 
A) to know: 
 Method of standardization and conditions of use. 
Standardization methods 
Terms of use and the stages of the direct method of standardization. 
Analysis of standardized indicators. 

B) be able to: 
Construct a table for the calculation of standardized indicators. 
Calculate and analyze the intense performance. 
Choose a standard. 
Calculate and analyze standardized indicators. 
Make a conclusion. 

5. Motivation: 
 The widespread introduction of computers and modern technology in modern medical practice and science led to the inevitable necessity of knowledge of biostatistics in the daily work of a physician and a follower and an understanding of basic statistical terms. The student must learn not only to calculate basic statistical quantities, but to be able to assess the credibility of the results and formulate sound conclusions. 
5.Mezhpredmetnye and vnutripredmetnye connection: It is envisaged continuity in teaching the following disciplines: biological physics and statistics, philosophy and economics, normal and pathological physiology, clinical disciplines of medicine, surgery, obstetrics, gynecology, pediatrics, dentistry, hygiene and epidemiology. 

6.  CONTENTS THEMES 

6.1 Theoretical part 

In practice doctors often have to compare the statistics calculated in a qualitatively heterogeneous composition of groups (gender, age, severity of patient in hospital). Must be aware that the intense performance, namely, they are often subject to over express the frequency of events in producing their environment. Hence the common indicators (mortality, fertility, mortality, morbidity, etc.) may influence heterogeneous composition of the compared populations. For example, to compare the overall levels of mortality (deaths per 100 patients) at two hospitals and conclude that the reasons for the differences of these indicators, one must first examine whether the uniform of nosological forms of the patients treated in these hospitals. Certainly, the overall mortality rate is higher in the hospital, where in the hospitalized patients were more people with serious chronic diseases. Fertility, for example, will be higher where more than the entire population of people of young age. Overall mortality is higher in the region where the population structure more young children and the elderly. On morbidity, injuries, and many others affected by the inhomogeneity of the composition by sex, age, seniority, occupation and. etc. Eliminate the influence of heterogeneity of composition may be, applying the method of standardization. 
Standardization - the method of calculating the conditional (standardized) indicators, replacing the general intensity (or average) value in cases where their comparison is difficult because of the incompatibility of the comparison groups. The essence of standardization is to calculate and analyze the conditional standardized indicators that show what would be the size and performance ratio, if the composition of the compared populations were similar. 
Standardized values ​​are conditional and are used for comparison purposes and not used to measure the actual level of a phenomenon and is the comparison does not apply. 
There are currently three methods of calculating standardized: 
Direct, applies in the case when you know the composition of the medium and the composition of the phenomenon. 
Indirect, applies in the case when you know the composition of the medium, but do not know the structure of the phenomenon or phenomena under study by the grounds expressed by small numbers. 
Inverse (indirect) used when make-up of events but did not know the structure of the medium. 
As can be seen the choice of method depends on the standardization of existing data, but the direct method of standardization is the most common. Thus, the application of the direct method of standardization allows for calculating the total intensity and indicators for groups. 
A direct method of standardization consists of 4 stages: 
Stage I - the calculation of general and specific intensive indicators for the two compared populations. 
Phase II - selection and calculation of the standard. In applying the direct method was adopted as a standard part of the environment, the choice of an arbitrary standard. From the selected standard ratio of standardized indicators will not change. 
Stage III - calculation of expected numbers. 
Stage IV - the calculation of standardized indicators, compare them with intensive, formulation of conclusions. 
The method of calculation of standardized indicators for example. So, we know the distribution of patients and deaths in hospitals, offices A and B (data conditional). Necessary to calculate standardized rates and compare with the general intensive fatality rates and make a conclusion: Does the structure of the patients according to the divisions on the overall mortality rate intensive or not? 
                                                                                                         Table № 1 

The number of past and patients who died in hospital departments A and B 

Branch 
	Hospital A	Hospital B	
	Number 
patients 
	Of them died 
	Mortality 
          % 
	Number 
patients 
	Of them died 
	Mortality 
          % 
	
Therapeutic 
	      1500	       180	180*100/1500
     = 12%	       500	         80	80*100/500
       =16%	
Surgical 
	      500	         30	30*100/500
      = 6%	        500	         40	40*100/500
      = 8%	
Infectious 
	      500	         20	20*100/500
         =4%	       1500	         90	90*100/1500
       = 6%	
Total 
	      2500	        230	230*100/2500
      =9,2%	       2500	        210	210*100/2500
       =8,4%	

         Stage I - the computation intensive fatality rates, according to the divisions and in general hospitals A and B. 
         When comparing the fatality rates in the 2 hospitals for each office can be seen that the mortality in the departments of the hospital B than in A, and the overall mortality rate for the entire hospital A than in B, respectively 9,2% against 8,4%. What explains this difference? Maybe it depends on the heterogeneity of past patients and their officers. In hospital B were more infectious patients in whom the mortality rate is the lowest. Therefore it is necessary to show what would be the case fatality rate in hospitals, if the number of past patients and their officers would be the same. 
        Phase II - selection and calculation of the standard. 
For the standard amount, or we can take half the amount of comparable populations, one of the compared populations, or any abstract collection. In our example, we take the floor for the standard amount of past patients of the hospital on A and B 
. 
Table № 2 

A standard calculation of expected numbers and standardized 

    Branch 
	    Standard 
	Expected number of deaths 
	Standardized	
		Hospital A	Hospital B	Hospital A	Hospital B 	
Therapeutic 
	1500+500/2
= 1000	12*1000/100
     = 120	16*1000/100
     = 160	

190*100/2500
          =7,6%	

260*100/2500
          =10,4%	
Surgical 
	500+500/2
= 500	6*500/100
     = 30	8*500/100
     = 40			
Infectious 
	500+1500/2
=1000	4*1000/100
     = 40	6*1000/100
     = 60			
Total 
	2500	120+40+30=190	160+40+60=260			

     Stage III - calculation of expected numbers. Expected number - are abstract numbers that say about what would be the size and the ratio of the studied groups, if the composition, comparable populations was the same. Ie in this case, the number of deaths in hospital departments A and B for the same number of patients in the past in these offices. The calculation is based on the argument that the mortality rate, for example, 12%, this means that out of 100 patients died, 12 while for the standard in 1000 patients with the number of deaths will be 120 people, examples of calculation are presented in table number 2 Expected number - this is the absolute magnitude therefore, to determine the total number simply add up the numbers obtained in the groups. 
     Stage IV - calculation of standardized indicators, compare them with intensive, formulation of conclusions. 
In this case, the resulting total expected number is expressed in% to the bottom line standards. 
     Conclusion: Comparison of standardized mortality rates in hospitals A and B, leads to the conclusion that for the same part of the last patients in offices mortality would be higher in hospital B than in A (10,4% and 7,6%) than general intensive fatality results were opposite (in A> B, sotvetstvenno9, 2% and 8,4%) due to the fact that the general intensive indicators influenced the different composition of past patients and their officers. Higher mortality rate in hospital and explains the predominance of her medical patients having the highest fatality rate and a lower mortality rate in hospital B is due to the predominance in it of infectious patients with the lowest mortality rate. 
     Thus, the main value of standardized indicators is that they provide the ability to compare performance across the composition of collections and allow to answer the question about where higher or lower than the value of the phenomenon under study with the deletion of the impact that heterogeneity of the composition. That is determined by the role of other factors influencing this phenomenon. 

6.2. Practical part 
  At the end of the topic, students receive a folder with handouts. Conducted a business game "Brainstorming" her graduation, students independently solve situational problems. Rated on a 100-point scale (100 - 86 - excellent, 85 - 71 well, 71 - 55 satisfying, less than 54 is not satisfactory). Score for engaging in forms for each student by an average of estimates for the theoretical part, a business game and to work independently and set to log in as an overall assessment of the occupation 

6.3 Analytical part students should undertake a comparative analysis of the results of work on the types of jobs with the information obtained in the lectures and self-training to engage on this topic, as well as the contents of the handout. 

6.4 used in the lesson, the new educational technology 
Business game " Brainstorm".

This technique teaches us to argue and defend their own point of view, to find the optimal solution in every situation, to build communication, to persuade opponents of loyalty to the position advocated. 
No comments and criticisms that prevented formirovke ideas; 
Greeting soaring thoughts, given that the unusual idea, the better; 
receiving the greatest number of proposals; 
combination of ideas and their development; 
brief statement, without argument deployed; 
division of those who generate ideas and those who handle them. 

Progress: The team is divided into 2 subgroups. Each group is invited to choose to formulate and discuss a problem or situation in order to select the greatest number of correct answers. Each correct answer is written as a score. Group received the highest number of points, put an excellent rating. 
Possible options for the proposed questions: 
Why can not compare directly the overall mortality rate in England and Uzbekistan? 
What method of standardization is preferable and why? 
If as a result of standardization obtained opposite (identical) results, what this means. 

7. Forms of knowledge and skills. 
Oral interview 
Parsing making common tasks 

8. Criteria for assessment of the current level of control
Levels	Rating count	Points Criteria evaluations
	
Excellent
86 - 100%	96 - 100	Answers originality, rationale, meet all program requirements, use additional information from the Internet, magazines, etc. He takes an active part in discussion topics, solving situational problems with the analysis and explanation.	
	91 -95	correct answers with interesting examples. Takes an active part in discussion topics, addressing situational tasks, with analysis and explanation.	
	86 -90	correct answers with interesting examples within the lecture and practical courses. Takes an active part in discussion topics, addressing situational tasks, with elements of analysis.
	
Well 
71 - 85.9%	81 - 85.9	correct answers in accordance with the scope of the program, not more. Decision situational tasks with an explanation, there may be minor errors.	
	76 - 80	answers within the textbook or lecture notes, perhaps glitches in the wording. Less active in the discussion of topics addressing the situational problems may be small errors.	
	71 - 75.9	responses within the textbook, perhaps minor inaccuracies, errors or difficulties in the wording. Passive, when discussing the topic, to solve situational problems of possible errors and errors of up to 20%.	
Satisfactory
55 - 70,9%	65 -70.9	Replies average from inaccuracies or errors. Passive, when discussing the topic, to solve situational problems of possible errors and errors of up to 30%. But does accurately notes in notebooks.	
	55 - 64.9	Weak knowledge of the theoretical question, the answers are not complete, with bugs. Passive, when discussing the topic, to solve situational problems and possible responses to errors and errors of up to 40%. Is not accurately notes in notebooks.	
Does not satisfy
Satisfactory
40 - 55%	50 -54.9	answers are not right, listens attentively to explanations of the teacher and student responses. Problem solved mene than 50%, no laptop leads neatly.	
	40 - 49.9	is not responding, not attentive, did not participate in the discussion of issues and solving situational problems.	

9. Chronological map of classes

№	Stages classes	Form of	Time	
1	Roll call and introduction of a teacher (study subjects)		5 minutes	
2	Discussion topics initial assessment of students' knowledge 	Poll	15 minutes	
3	Carrying out online game "Work in small groups" 	Business Game	5min	
4	independent work of students on the assignments obtained 
	Independent Work	35 minutes	
5	Report on the results of independent work 	Checking
Results	20 minutes	
6	Reciprocal analysis of the results of independent work by students under the guidance of teacher evaluation on 100 point system method of calculating the average of the oral response, a business game, independent work. 	Information teacher	10minut	

10. Test questions 
What is standardization? 
What are my standards? 
Conditions for applying the direct method of standardization. 
Stages of the direct method of standardization. 
Why expect special intense performance in the comparative groups? 
The choice of standard and its calculation. 
The content of Phase III standardization? 
As evidenced by standardized indicators and their calculation? 

11. Exercises for independent work 

Problem number 1 
Calculate standardized rates, mortality rates for the year in 2 hospitals and compared them with mortality rates, calculated in the usual way, draw the appropriate conclusions. For the standard to the composition of patients in hospital A. 
Distribution of patients and deaths by nosological forms in hospitals 
A and B (in absolute numbers). 

Disease name 
	Hospital A 
	Hospital	
	number. patients 
	number. dead 
	number. patients 
	number. dead 
	
Hypertonic disease 
	360	9	400	8	
Stomach cancer 
	200	70	480	144	
Myocardial infarction 
	270	18	320	20	
Total: 
	830	97	1200	172	

Problem number 2 
Calculate standardized rates, hypertension, and compared them with those calculated in the usual way, draw the appropriate conclusions. For the standard to the composition of the surveyed residents on the floor (the floor amount for the two regions). 
The distribution of hypertensive patients on the floor in areas A and B 

(In absolute terms). 
Paul 
	Area A 
	Area B	
	number of subjects 
	number of patients 
	number of subjects 
	number of patients 
	
Men	500	8	1000	17	
Wemen	900	55	400	30	
Total: 	1400	63	1400	47	

task № 3 
Calculate the standardized indicators of injury to two plants and comparing them with those calculated in the usual way, draw the appropriate conclusions. Number of employees and number of injuries in industry (in absolute terms). 
    
Paul 
	Area A	Area B	
	District office's 
	number. injuries 
	number. slave
	number. injuries
	
Men	200	32	700	98	
wemen	400	28	200	12	
Total: 	600	60	900	110	

12. Razdatochny material 
№ 1 Determination of the correlation coefficient by the method of ranks. 
№ 2 Determination of the correlation coefficient by the method of squares. 
№ 3Opredelenie regression coefficient. 
№ 4Opredelenie coefficient of linear regression. 
№ 5Otsenochnaya table 
№ 6 Objectives 

13. Recommended Reading: 
 Main: 
1. Serenko AF, Ermakov VV Social Care and Health Organization, "Moscow. 1984. 
2. Lisitsyn YP Hooves NY Guidelines for practical training in social hygiene ", Moscow. 1984. 
3. The texts of lectures on "Social Hygiene and Public Health Organization" in the library TMA. 
More: 

1. Lisitsyn YP et al. "Social Hygiene and Public Health Organization" in 2 volumes, Volume 2, Moscow. 1989. 
2.Lisitsin Yu.P. Polunin H. MV <Public Health and Health Care>> Moscow. 2002.