3.2.1 Data
This study is based on a secondary analysis of the data from the (EDHS 2005). The survey was conducted from April 27 to August 30, 2005. The survey sample was designed to provide national, urban/rural, and regional estimates of key Health and demographic indictors. In the first stage, 540 clusters were selected from the list of Enumeration Areas (EA) in the 1994 population and housing census. Fieldwork was successfully completed in 535 of the 540 clusters. In the second stage, 24 to 32 households were selected systematically from each cluster for the survey sample.
The survey administered the women’s questionnaire to all eligible women in age 15-49
in the sampled households. The men’s questionnaire was administered to all eligible men aged 15-59 in every household. In order to test for HIV the survey collected blood specimens from all eligible women and men in the household selected for the male interview. The response rates for HIV testing were 83% among women and 76%
among men . The analysis used data from 14070 women and 6033 men age who had completed interview, who reported ever having had sexual intercourse, and who had a valid HIV test results. Because of the way the sample was designed, the number of cases in some regions appears small since they are weighted to make the regional distribution nationally representative.
In order to carry out the test of HIV, in a random sample of 50% of the households selected from the survey, all eligible women and men were asked to provide their consent for a blood draw and subsequent testing for HIV; in case of young in age 15-17 the consent was obtained from their parent. Everyone for whom consent was obtained provided three to four drops of blood from a finger prick collected on a filter paper with a special bar code label. The blood samples were transported to Addis Ababa to be tested for HIV at the Ethiopia Health and Nutrition Research Institute (EHNRI), a national laboratory. HIV testing was conducted using standard laboratory and quality control procedures. The blood collection and HIV testing protocol allowed anonymous linking of the HIV test result to an individual’s socio-demographic and behavioural characteristics obtained from the individual questionnaires. Bar codes were used to make this link, after household and cluster identification codes were scrambled to ensure that all potential identifiers had been destroyed.
3.2.2 Covariates
The independent variables included sociodemographic characteristics (age, region, place of residence, education, religion, marital status), Socio-cultural factors (decision making ability, wealth index, stigma, circumcision), sexual behaviour characteristics (number of sexual partners in the last 12 months, history of STI in the last 5 years, age at first sex).
Principle Component Analysis (PCA) [48] was used to generate the stigma, media exposure and the ability of decision making. Stigma is defined as an attribute or label that sets a person apart from others and links the labeled person to undesir- able characteristics [36]. Stigma related to AIDS has been defined as ”the prejudice, discounting, discrediting, and discrimination that are directed at people perceived to
have AIDS” [64]. A stigma index was created based on responses to the questions
”willing to care for relative with AIDS”, ”person with AIDS allowed to continue” and
”would buy vegetables from vendor with AIDS ”. Based on factor scores, respondents were classified as having low, medium or high HIV-related stigma. A media exposure index was also computed using PCA based on responses to questions posed on the frequency of watching television, the frequency of listening to radio, and the frequency of reading newspapers. The respondents were then classified as having low, medium or high media exposure. The decision making index was computed based on the respon- dents answer to the questions: Final say on own health care, final say on making large household purchases, final say on making household purchases for daily need, final say on visits to family or relatives, final say on food to be cooked each day, and final say on deciding what to do with money husband earns. The decision making index was a trichotomous variable with levels defined as independent, consults and subservient.
3.2.3 Analysis plan
Separate analysis were carried out for the male and female data because the biological and social circumstances associated with transmission of HIV differ by sex. The HIV serostatus was the primary response variable in this analysis. Several other variables identified from the literature were cross-classified with this variable. SAS 9.2 (SAS Institute, Cary, NC) was used to carry out statistical analyses. Univariate analysis was done to assess the distribution of the sample and to compute overall prevalence of HIV. Both point estimates and robust 95% confidence intervals (based on robust standard errors after adjusting for strata and clustering at Primary Sampling Unit (PSU) level are presented. Bivariate and multivariate survey logistic regression models were used to assess the unadjusted and adjusted association, respectively, of different socioeconomic, demographic characteristics with HIV. Both bivariate and multivariate regression models were fitted after applying sampling weights and adjusting for multi- stage clustered sampling designs effects using PROC SURVEYLOGISTIC in SAS 9.2 (SAS Institute, Cary, NC)