title: Creating and validating an algorithm to measure AIDS mortality in the adult population using verbal autopsy.
abstract: BACKGROUND
  Vital registration and cause of death reporting is incomplete in the countries in which the HIV epidemic is most severe. A reliable tool that is independent of HIV status is needed for measuring the frequency of AIDS deaths and ultimately the impact of antiretroviral therapy on mortality.
  
  
  RESULTS
  A verbal autopsy questionnaire was administered to caregivers of 381 adults of known HIV status who died between 1998 and 2003 in Manicaland, eastern Zimbabwe. Individuals who were HIV positive and did not die in an accident or during childbirth (74%; n = 282) were considered to have died of AIDS in the gold standard. Verbal autopsies were randomly allocated to a training dataset (n = 279) to generate classification criteria or a test dataset (n = 102) to verify criteria. A rule-based algorithm created to minimise false positives had a specificity of 66% and a sensitivity of 76%. Eight predictors (weight loss, wasting, jaundice, herpes zoster, presence of abscesses or sores, oral candidiasis, acute respiratory tract infections, and vaginal tumours) were included in the algorithm. In the test dataset of verbal autopsies, 69% of deaths were correctly classified as AIDS/non-AIDS, and it was not necessary to invoke a differential diagnosis of tuberculosis. Presence of any one of these criteria gave a post-test probability of AIDS death of 0.84.
  
  
  CONCLUSIONS
  Analysis of verbal autopsy data in this rural Zimbabwean population revealed a distinct pattern of signs and symptoms associated with AIDS mortality. Using these signs and symptoms, demographic surveillance data on AIDS deaths may allow for the estimation of AIDS mortality and even HIV prevalence.
authors.affiliation: Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom. b.lopman@imperial.ac.uk
authors.forename: Ben A
authors.initials: BA
authors.lastname: Lopman
authors.forename: Ruanne V
authors.initials: RV
authors.lastname: Barnabas
authors.forename: J Ties
authors.initials: JT
authors.lastname: Boerma
authors.forename: Godwin
authors.initials: G
authors.lastname: Chawira
authors.forename: Kezia
authors.initials: K
authors.lastname: Gaitskell
authors.forename: Tara
authors.initials: T
authors.lastname: Harrop
authors.forename: Peter
authors.initials: P
authors.lastname: Mason
authors.forename: Christl A
authors.initials: CA
authors.lastname: Donnelly
authors.forename: Geoff P
authors.initials: GP
authors.lastname: Garnett
authors.forename: Constance
authors.initials: C
authors.lastname: Nyamukapa
authors.forename: Simon
authors.initials: S
authors.lastname: Gregson
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D017028:Caregivers; D002423:Cause of Death; D005260:Female; D015658:HIV Infections / Q000175:diagnosis / Q000401:mortality*; D006801:Humans; D007407:Interviews as Topic / Q000379:methods*; D008297:Male; D016036:Seroepidemiologic Studies; D011795:Surveys and Questionnaires; D015030:Zimbabwe / Q000453:epidemiology