Validation of AIDS-related mortality in Botswana

Mortality data are used to conduct disease surveillance, describe health status and inform planning processes for health service provision and resource allocation. In many countries, HIV- and AIDS-related deaths are believed to be under-reported in government statistics.

To estimate the extent of under-reporting of HIV- and AIDS-related deaths in Botswana, we conducted a retrospective study of a sample of deaths reported in the government vital registration database from eight hospitals, where more than 40% of deaths in the country in 2005 occurred. We used the consensus of three physicians conducting independent reviews of medical records as the gold standard comparison. We examined the sensitivity, specificity and other validity statistics.

Of the 5276 deaths registered in the eight hospitals, 29% were HIV- and AIDS-related. The percentage of HIV- and AIDS-related deaths confirmed by physician consensus (positive predictive value) was 95.4%; however, the percentage of non-HIV- and non-AIDS-related deaths confirmed (negative predictive value) was only 69.1%. The sensitivity and specificity of the vital registration system was 55.7% and 97.3%, respectively. After correcting for misclassification, the percentage of HIV- and AIDS--related deaths was estimated to be in the range of 48.8% to 54.4%, depending on the definition.

Improvements in hospitals and within government offices are necessary to strengthen the vital registration system. These should include such strategies as training physicians and coders in accurate reporting and recording of death statistics, implementing continuous quality assurance methods, and working with the government to underscore the importance of using mortality statistics in future evidence-based planning.