1. Unit 7: Data Management, Analysis and Interpretation #3-7-1

2. Warm Up Questions: Instructions  Take five minutes now to try the Unit 7 warm up questions in your manual.  Please do not compare answers with other participants.  Your answers will not be collected or graded.  We will review your answers at the end of the unit. #3-7-2

3. What You Will Learn  By the end of this unit you should be able to: © describe the process for sero-survey data entry © list the variables for analysing sentinel surveillance data #3-7-3

4. Data Entry and Management  Following demographic data collection and laboratory testing for HIV, results are brought to a site for data entry.  This site can be at the clinic, regional or national level.  If available, computers would be used to merge these results. #3-7-4

5. Databases  Data entry is the process of entering paper records into a computer database.  Databases store the variables for each patient in the survey sample.  Data can be stored either as numbers or text. Most variables will be converted into numbers. #3-7-5

6. Databases, Cont.  Databases and data entry screens are set up centrally by information technology staff at the national level.  Data entry screens are the forms on the computer screen into which a data entry clerk enters the data. #3-7-6

7. Figure 7.1. Sample Data Entry Screen #3-7-7

8. Data Dictionaries  electronic files that describe the basic organization of a project or database  contain all of the rules that guide data entry  should also be developed centrally #3-7-8

9. Steps for Data Entry  Enter data either as numbers or text, depending on the variable, for each patient.  Save, and go on to the next patient.  Data entry should be a continuous process, to avoid backlogs and the consequent errors.  Re-enter the data. Ideally, all data are double-entered. #3-7-9

10. Table 7.1. Checking Data for Errors #3-7-10 MethodDescription Automaticchecking uses a computer programme with a built-in check function, such as Epi Info™ Manualchecking involves looking over data to see if there are patterns that suggest problems with the data

11. Analysis and Interpretation  Data from sentinel surveillance should be analysed and interpreted in conjunction with other data.  These other data may include: © STI prevalence © behavioural data © AIDS case surveillance #3-7-11

12. Analysis and Interpretation, Cont.  Analysing and interpreting sentinel surveillance data is guided by the following questions: © Is the prevalence of HIV increasing, decreasing or remaining essentially stable? © What is the trend in HIV prevalence among 15- to 19-year-olds? © Which sentinel sites have the highest HIV prevalence? #3-7-12

13. Analysis and Interpretation, Cont. © Which groups have the highest HIV prevalence? © In which groups is HIV prevalence rising? Falling? © What are the differences between sites where the prevalence of HIV infection is low and those where it is relatively high? © What are the differences between sites where the prevalence of HIV infection is increasing, and those where there is a decrease or no change? #3-7-13

14. Examining Trends  Analysis of HIV sentinel surveillance data should focus on the prevalence of HIV by person, place and time.  Changes in prevalence by time are most important.  Changes over time may reflect real changes in prevalence if surveillance methods are consistent. #3-7-14

15. Examining Trends, Cont.  A focus on the trend, rather than absolute prevalence, is a principle of second- generation HIV surveillance.  Trends in HIV prevalence among 15- to 19- year-olds are most likely to reflect trends in HIV incidence. #3-7-15

16. Analysis by Variable  Sentinel surveillance data should be analysed by each of the variables collected: © year of survey © sentinel site, district, province and region © age group © female and male (if other than ANC) © residence (for example, rural versus urban) © marital status © other demographic variables if collected © risk behaviour if collected © presence of STIs #3-7-16

17. Analysis by Variable, Cont.  Analyse results separately for each site.  Report data for HIV-1 and HIV-2 separately, if relevant.  Results should be summarised for the entire survey sample at each site, and for each sub- group. #3-7-17

18. Analysis by Variable, Cont.  Do not summarise sentinel surveillance data by calculating a single prevalence figure for the whole survey (that is, all the sites).  Remember, results cannot be generalised to the rest of the population.  Summary information can, at best, be presented as the median and range for each type of sentinel site, on a regional and national basis. #3-7-18

19. Warm Up Review  Take a few minutes now to look back at your answers to the warm up questions at the beginning of the unit.  Make any changes you want to.  We will discuss the questions and answers in a few minutes. #3-7-19

20. Answers to Warm Up Questions 1.Data Entry is the process of entering paper records into a computerized database. #3-7-20

21. Answers to Warm Up Questions, Cont. 2.True or false? The best way to summarise sentinel surveillance data is by calculating a single prevalence figure for the whole survey. False #3-7-21

22. Answers to Warm Up Questions, Cont. 3.True or false? Data dictionaries, that is, electronic files that describe the basic organisation of a project or database, should be developed at the local clinic level. False #3-7-22

23. Small Group Discussion: Instructions  Get into small groups to discuss these questions.  Choose a speaker for your group who will report back to the class.  Take 15 minutes for this exercise. #3-7-23

24. Small Group Reports  Select one member from your group to present your answers.  Discuss with the rest of the class. #3-7-24

25. Case Study: Instructions  Try this case study individually.  We’ll discuss the answers in class. #3-7-25

26. Case Study Review  Follow along as we go over the case study in class.  Discuss your answers with the rest of the class. #3-7-26

27. Questions, Process Check  Do you have any questions on the information we just covered?  Are you happy with how we worked on Unit 7?  Do you want to try something different that will help the group? #3-7-27