Research question
What is the impact of the implementation of anti-retroviral treatment programmes on both All cause mortality and Cause specific mortality
Rationale
Comprehensive antiretroviral therapy (ART) coverage aims to reverse the substantial increase in HIV-related deaths in populations with high HIV prevalence, but its impact on a population level remains to be quantified. We used a demographic surveillance system to investigate trends in adult mortality in a population serviced by a public-sector ART programme in rural South Africa.
Fit with Africa Centre research strategy
This investigation forms part of population-based research agenda of the Centre and takes advantage of our knowledge of ART roll-out in this area and links with the clinical research agenda with regards to the estimation of treatment need and access.
Data sources and methods
The denominator data is obtained from the routine surveillance of resident households in the demographic surveillance area. Biannual surveillance visits to all homesteads within the DSA were performed by fieldwork teams to record births, deaths and any in- and out-migrations of household members. Household membership is self-defined on the basis of links to other household members. A resident is a member of a household who normally lives in the same homestead as the other members, whereas a non-resident household members normally lives elsewhere but retain links to the household. Individuals contributed to the person-years denominator from the beginning of the surveillance (1 January 2000), or from any later date of birth or in-migration, until the end of the study period, and they ceased to contribute to the denominator at death, termination of household membership, household out-migration or the last surveillance visit in which household membership was confirmed. Thus, individuals who were previous homestead residents continued to be followed when they became non-residents for as long as they remained a member of – i.e. retained links with – the household under surveillance.
All deaths notified in both residents and non-residents are followed up by a verbal autopsy interview conducted an average of 6 months after the person’s death by a trained nurse. The closest caregiver of the deceased is interviewed and asked to provide a narrative of the circumstances leading up to the death of the individual and to reply to a checklist of signs and symptoms and a standard structured questionnaire based on the INDEPTH standard questionnaire for verbal autopsies. The ICD-10 codes are mapped into global burden of disease groups I, II and III with the exception of tuberculosis and AIDS diagnoses, which are classified together into a separate group as HIV-related deaths, given the considerable overlap in mortality from HIV infection and tuberculosis. The analysis dataset used is the Africa Centre demographic dataset.
Findings
Verbal autopsies were conducted on all 7,930 deaths observed between January 2000 and December 2006 in the surveillance population of 74,500. Age-standardised mortality rate ratios (SMRR) were calculated for adults (aged 25 to 49 years) for the two years before and three years after antiretroviral programme initiation in 2004. From 2002-3 (pre-ART) to 2004-6 (post-ART), HIV-related age-standardised mortality declined significantly from 22.52 to 17.58 per 1,000 person-years in women aged 25-49 years (p<0.001, SMRR 0.780 95% CI 0.691‑0.881) and from 26.46 to 18.68 per 1,000 person-years in men aged 25-49 years old (p<0.001, SMRR 0.706 95% CI 0.615‑0.811). A sensitivity analysis showed that the results were robust to possible effect of misclassification of HIV-related deaths.
Policy implications
We show a significant decline in overall population mortality and HIV-related adult mortality following ART roll-out, in a high HIV prevalence community. As part of a multi faceted approach to encourage all to know their HIV status and access care, these findings should be part of a clear public health message of the benefits of treatment.
Further work
The analysis will be repeated to assess the impact of the ART roll-out over a longer period of time, and to further investigate the trends in non-HIV-related mortality to be vigilant in terms of a possible ‘crowding’ out of non-HIV care by the increasingly expansive HIV treatment programme in the health care delivery.