Research report 1Department of Infectious Disease Epidemiology, Imperial College, London, UK 2National Institute for Medical Research, Mwanza, Tanzania 3Biomedical Research and Training Institute, Harare, Zimbabwe 4Health Protection Agency, London, UK 5Centre for Population Studies, London School of Hygiene and Tropical Medicine, London, UK 6World Health Organization, Geneva, Switzerland Correspondence to Ben Lopman, Imperial College, London, UK; blopman@gmail.com Accepted 27 May 2009 Published Online First 23 October 2009 This paper is freely available online under the BMJ Journals unlocked scheme, see http:// jech.bmj.com/site/about/ unlocked.xhtml. 330 Verbal autopsy can consistently measure AIDS mortality: a validation study in Tanzania and Zimbabwe B Lopman,1 A Cook,2 J Smith,1 G Chawira,3 M Urassa,2 Y Kumogola,2 R Isingo,2 C Ihekweazu,4 J Ruwende,4 M Ndege,2 S Gregson,1,3 B Zaba,2,5 T Boerma6 ABSTRACT Background Verbal autopsy is currently the only option for obtaining cause of death information in most populations with a widespread HIV/AIDS epidemic. Methods With the use of a data-driven algorithm, a set of criteria for classifying AIDS mortality was trained. Data from two longitudinal community studies in Tanzania and Zimbabwe were used, both of which have collected information on the HIV status of the population over a prolonged period and maintained a demographic surveillance system that collects information on cause of death through verbal autopsy. The algorithm was then tested in different times (two phases of the Zimbabwe study) and different places (Tanzania and Zimbabwe). Results The trained algorithm, including nine signs and symptoms, performed consistently based on sensitivity and speciﬁcity on verbal autopsy data for deaths in 15e44-year-olds from Zimbabwe phase I (sensitivity 79%; speciﬁcity 79%), phase II (sensitivity 83%; speciﬁcity 75%) and Tanzania (sensitivity 75%; speciﬁcity 74%) studies. The sensitivity dropped markedly for classifying deaths in 45e59-year-olds. Conclusions Verbal autopsy can consistently measure AIDS mortality with a set of nine criteria. Surveillance should focus on deaths that occur in the 15e44-year age group for which the method performs reliably. Addition of a handful of questions related to opportunistic infections would enable other widely used verbal autopsy tools to apply this validated method in areas for which HIV testing and hospital records are unavailable or incomplete. Verbal autopsy, in which care givers to the deceased report information on signs, symptoms and circumstances preceding death,1e3 is currently the best option for obtaining cause of death information in populations without comprehensive civil regis- tration systems. WHO, through the Health Metrics Network, is co-ordinating an effort to develop a common tool for verbal autopsy, since there is an urgent need to validate currently used questions for different populations, settings and causes of mortality.4 There is particular need to develop methods to measure AIDS mortality, which is the leading cause of death among young adults in virtually all coun- tries with generalised HIV epidemics. Improving measurement of AIDS mortality is crucial since the ultimate goal of interventionsdincluding the scale up of antiretroviral treatmentdis to reduce AIDS mortality.5 Monitoring the success of such programmes therefore relies on accurate measure- ment of AIDS deaths in the community.6 7 Hospital records and vital registration of deaths are especially inadequate for estimating the level of AIDS as a cause of mortality because of bias, underreporting and stigma associated with the disease.8 Two longitudinal community studies in Tanzania and Zimbabwe provide a unique opportunity to investigate the most sensitive and speciﬁc set of questions to ascertain HIV/AIDS-associated mortality. Both studies have collected information on the HIV status of the population over a prolonged period and maintained a demographic surveillance system (DSS) that collects information on cause of death through verbal autopsy. At the time of the verbal autopsy studies, HIV prevalence was approximately 20% in the Zimbabwe cohort and 7% in the Tanzania cohort.9 10 With data from the Zimbabwe study, we developed a computer algorithm to classify AIDS deaths from verbal autopsy data11 12 validated using serological data from deaths that occurred from 1998 to 2003. Before the algorithm can be widely used, it must be demonstrated that it performs similarly and predictably in different settings of high HIV-asso- ciated mortality (validation in place) and can perform well at different phases of the epidemic when levels of AIDS mortality differ (validation in time). METHODS All participants of both cohorts were followed as part of demographic surveillance and were tested for HIV at each sero-survey. If an individual died between follow-ups, an attempt was made to perform verbal autopsy. An individual’s HIV status at death was assumed to be the same as at his/her most recent test, which was a maximum of 3 years prior. The Manicaland Project includes a population- based open cohort study in the rural province of Manicaland in eastern Zimbabwe.9 The study population were residents in two forested small towns, four tea and coffee estates and six rural areas (including four subsistence farming and two road- side trading centres). A baseline survey took place from 1998 to 2000, with two follow-ups occurring 3 and 5 years later (the intersurvey periods are referred to here as phase I and phase II). Of the households, 8376 and 7102 identiﬁed in the survey areas at phase I and phase II, respectively, were enumerated. Male and female participation rates in the individual cohort study survey were 78% (4320/ J Epidemiol Community Health 2010;64:330e334. doi:10.1136/jech.2008.081554