Creating and Validating an Algorithm to Measure AIDS Mortality in the Adult Population using Verbal Autopsy

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. METHODS AND FINDINGS: 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

Voluntary counselling and testing: uptake, impact on sexual behaviour, and HIV incidence in a rural Zimbabwean cohort.

OBJECTIVES: To examine the determinants of uptake of voluntary counselling and testing (VCT) services, to assess changes in sexual risk behaviour following VCT, and to compare HIV incidence amongst testers and non-testers. METHODS: Prospective population-based cohort study of adult men and women in the Manicaland province of eastern Zimbabwe. Demographic, socioeconomic, sexual behaviour and VCT utilization data were collected at baseline (1998-2000) and follow-up (3 years later). HIV status was determined by HIV-1 antibody detection. In addition to services provided by the government and non-governmental organizations, a mobile VCT clinic was available at study sites. RESULTS: Lifetime uptake of VCT increased from under 6% to 11% at follow-up. Age, increasing education and knowledge of HIV were associated with VCT uptake. Women who took a test were more likely to be HIV positive and to have greater HIV knowledge and fewer total lifetime partners. After controlling for demographic characteristics, sexual behaviour was not independently associated with VCT uptake. Women who tested positive reported increased consistent condom use in their regular partnerships. However, individuals who tested negative were more likely to adopt more risky behaviours in terms of numbers of partnerships in the last month, the last year and in concurrent partnerships. HIV incidence during follow-up did not differ between testers and non-testers. CONCLUSION: Motivation for VCT uptake was driven by knowledge and education rather than sexual risk. Increased sexual risk following receipt of a negative result may be a serious unintended consequence of VCT. It should be minimized with appropriate pre- and post-test counselling

Comparison of observed HIV prevalence by age in Manicaland, with 95% confidence intervals, to the Zimbabwe national HIV estimates from UNAIDS and the Zimbabwe Ministry of Health and Child Welfare.

<p>Comparison of observed HIV prevalence by age in Manicaland, with 95% confidence intervals, to the Zimbabwe national HIV estimates from UNAIDS and the Zimbabwe Ministry of Health and Child Welfare.</p

Association between demographic characteristics and HIV infection in children.

†<p>Unadjusted odds ratio.</p>‡<p>Fisher's exact test for difference of proportions.</p>a<p>Total respondents (N = 2206) is lower than other categories due to maternal orphans (n = 348), unlinked records (n = 722) and question non-response (n = 113).</p><p>Association between demographic characteristics and HIV infection in children.</p

Association between HIV status and potential horizontal risk factors for HIV.

†<p>Adjusted odds ratio; adjusted for age, gender, SES, and site type.</p>‡<p>Fisher's exact test for difference of proportions.</p><p>NB: Different Ns are due to different question non-response rates.</p><p>Association between HIV status and potential horizontal risk factors for HIV.</p

Effects of HIV status on physical and mental health outcomes in children and adolescents.

†<p>Adjusted odds ratio; adjusted for age, gender, SES, and community type.</p>‡<p>Children 2–5 only.</p>a<p>Mean and change in score between HIV− and HIV+; ages 6–14 only.</p><p>Effects of HIV status on physical and mental health outcomes in children and adolescents.</p

Measuring and correcting biased child mortality statistics in countries with generalized epidemics of HIV infection

OBJECTIVE: Under Millennium Development Goal 4, countries are required to reduce child mortality by two-thirds between 1990 and 2015. In countries with generalized epidemics of human immunodeficiency virus (HIV) infection, standard statistics based on fertility history may misrepresent progress towards this target owing to the correlation between deaths among mothers and early childhood deaths from acquired immunodeficiency syndrome. METHODS: To empirically estimate this bias, child mortality data and fertility history, including births to deceased women, were collected through prospective household surveys in eastern Zimbabwe during 1998-2005. A mathematical model was then used to investigate the determinants and temporal dynamics of the bias, first in Zimbabwe and then in other countries with different background mortality rates and HIV-related epidemic profiles. FINDINGS: According to the empirical data, standard cross-sectional survey statistics underestimated true infant and under-5 mortality by 6.7% and 9.8%, respectively. These estimates were in agreement with the output from the model, in which the bias varied according to the magnitude and stage of the epidemic of HIV infection and background mortality rates. The bias was greater the longer the period elapsed before the survey and in later stages of the epidemic. Bias could substantially distort the measured effect of interventions to reduce non-HIV-related mortality and of programmes to prevent mother-to-child transmission, especially when trends are based on data from a single survey. CONCLUSION: The correlation between the HIV-related deaths of mothers and their children can bias survey estimates of early child mortality. A mathematical model with a user-friendly interface is available to correct for this bias when measuring progress towards Millennium Development Goal 4 in countries with generalized epidemics of HIV infection

Derivation of Gold Standard from HIV Serostatus at Baseline in the Train and Test Datasets

<p>Derivation of Gold Standard from HIV Serostatus at Baseline in the Train and Test Datasets</p