Tracking ‘Silent’ Deaths

Researchers uncover underreporting of HIV mortality rates in Zambia

Zambia’s HIV mortality rates for patients in treatment are substantially underreported, according to a new study called Better Information for Health in Zambia. Researchers arrived at more accurate mortality rates using a novel sampling methodology that may be a model for improved surveillance approaches, and ultimately, more effective HIV treatment strategies.

Official sources report that AIDS-related deaths have fallen by 50 percent since 2005. However, routine monitoring and evaluation fail to systematically capture most deaths, making it challenging to accurately assess the impact of HIV services and to identify where improvement is most needed, the researchers say.

“Deaths often occur outside of the health system and are therefore ‘silent’ events unknown to those providing or managing care,” says the study’s co-leader, Charles Holmes, MD, MPH.

Holmes is faculty codirector of Georgetown University Medical Center’s Center for Global Health and Quality, a visiting associate professor at Georgetown’s School of Medicine, as well as associate professor of international health and medicine at Johns Hopkins University. The research was conducted in Zambia through partnerships with the Centre for Infectious Disease Research in Zambia, the Zambian Ministry of Health, and with local and global academic centers and researchers.

Researchers looked at a sample of 160,000 patients who had visited governmentoperated HIV treatment sites in four Zambian provinces. The team also traced the “lost to follow-up” patients, in order to ascertain their status. They used this information to create a corrected regional survival estimate as well as corrected site-specific mortality estimates. The team found underreporting of mortality rates in provincial program data—by as much as three- to nine-fold— among HIV-infected individuals starting antiretroviral therapy (ART). At the clinic site-level, “corrected” mortality rates were found to be up to 23-fold higher among those on ART.

Based on the findings, certain prevailing assumptions that underlie HIV programs may need to be re-examined, say the researchers. For example, length of time on therapy alone may not be a reliable marker of stability, a finding that will have implications for delivery strategies. Additionally, approximately 50 percent of deaths among those newly starting ART occurred shortly after a clinic visit, suggesting greater need for attention to diagnostic services and clinical vigilance for co-existing illnesses.

The authors seek to encourage national- and global-level policy makers to investigate and address the root causes of underestimated and highly variable mortality rates, so they can refocus their quality improvement efforts and strengthen HIV programs.

“We believe our study also highlights the critical need for investments in vital status registries and data systems, to enable better visibility into patient outcomes,” adds Holmes.