Figure 1.

National adult HIV prevalence estimates with 95% CI derived from three modelling approaches for men and women from 12 Demographic and Health Surveys conducted in sub-Saharan Africa, 2001–2009. Women aged 15–49 years were eligible to be tested for HIV. The age range for men was 15–59 years, with the exceptions of Cote d'Ivoire, Liberia and Swaziland (15–49 years) and Malawi and Zimbabwe (15–54 years). HIV infection was defined as infection with either HIV-1 or HIV-2. Apart from the selection variables described in the text, all other covariates were shared by the two model components of the selection models and the conventional imputation probit regressions. For ‘consent’ regressions, these variables were: age, educational attainment, household wealth quintile as constructed from an index of household assets, urban setting, region, interview language, ethnicity, religion, marital status, high-risk sexual behaviour in the past year, condom use at last sex, sexually transmitted disease in the past year, tobacco and alcohol use, knowing someone with AIDS, willingness to care for a family member with AIDS, and having had a previous HIV test. For ‘contact’ regressions, these variables were: sex, age, education, wealth quintile, urban setting and region (see details in online technical appendix). ‘Extreme bounds’ assume that all those missing a valid HIV test are uniformly HIV-positive or HIV-negative.