Pitfalls of practicing cancer epidemiology in resource-limited settings: the case of survival and loss to follow-up after a diagnosis of Kaposi’s sarcoma in five countries across sub-Saharan Africa
Open Access
- 6 February 2016
- journal article
- research article
- Published by Springer Science and Business Media LLC in BMC Cancer
- Vol. 16 (1), 1-7
- https://doi.org/10.1186/s12885-016-2080-0
Abstract
Survival after diagnosis is a fundamental concern in cancer epidemiology. In resource-rich settings, ambient clinical databases, municipal data and cancer registries make survival estimation in real-world populations relatively straightforward. In resource-poor settings, given the deficiencies in a variety of health-related data systems, it is less clear how well we can determine cancer survival from ambient data. We addressed this issue in sub-Saharan Africa for Kaposi’s sarcoma (KS), a cancer for which incidence has exploded with the HIV epidemic but for which survival in the region may be changing with the recent advent of antiretroviral therapy (ART). From 33 primary care HIV Clinics in Kenya, Uganda, Malawi, Nigeria and Cameroon participating in the International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortia in 2009–2012, we identified 1328 adults with newly diagnosed KS. Patients were evaluated from KS diagnosis until death, transfer to another facility or database closure. Nominally, 22 % of patients were estimated to be dead by 2 years, but this estimate was clouded by 45 % cumulative lost to follow-up with unknown vital status by 2 years. After adjustment for site and CD4 count, age <30 years and male sex were independently associated with becoming lost. In this community-based sample of patients diagnosed with KS in sub-Saharan Africa, almost half became lost to follow-up by 2 years. This precluded accurate estimation of survival. Until we either generally strengthen data systems or implement cancer-specific enhancements (e.g., tracking of the lost) in the region, insights from cancer epidemiology will be limited.Keywords
This publication has 36 references indexed in Scilit:
- Treatment Response and Mortality among Patients Starting Antiretroviral Therapy with and without Kaposi Sarcoma: A Cohort StudyPLOS ONE, 2013
- Evaluation of data quality at the Gambia national cancer registryInternational Journal of Cancer, 2012
- HIV Co-receptor usage in HIV-related non-hodgkin's lymphomaInfectious Agents and Cancer, 2012
- Estimating Loss to Follow-Up in HIV-Infected Patients on Antiretroviral Therapy: The Effect of the Competing Risk of Death in Zambia and SwitzerlandPLOS ONE, 2011
- Correcting Mortality for Loss to Follow-Up: A Nomogram Applied to Antiretroviral Treatment Programmes in Sub-Saharan AfricaPLoS Medicine, 2011
- Understanding Reasons for and Outcomes of Patients Lost to Follow-Up in Antiretroviral Therapy Programs in Africa Through a Sampling-Based ApproachJAIDS Journal of Acquired Immune Deficiency Syndromes, 2010
- AIDS‐associated Kaposi's sarcoma is linked to advanced disease and high mortality in a primary care HIV programme in South AfricaJournal of the International AIDS Society, 2010
- Mortality of Patients Lost to Follow-Up in Antiretroviral Treatment Programmes in Resource-Limited Settings: Systematic Review and Meta-AnalysisPLOS ONE, 2009
- Sampling-Based Approaches to Improve Estimation of Mortality among Patient Dropouts: Experience from a Large PEPFAR-Funded Program in Western KenyaPLOS ONE, 2008
- A note on competing risks in survival data analysisBritish Journal of Cancer, 2004