title: 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.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Bartlett Hall 6R, 55 Fruit Street, Boston, MA, 02114, USA. efreeman@mgh.harvard.edu.
authors: Esther
authors: E
authors: Freeman
authors: Infectious Diseases Institute, Makerere University, Kampala, Uganda.|University of California, San Francisco, USA.
authors: Aggrey
authors: A
authors: Semeere
authors: University of California, San Francisco, USA.
authors: Megan
authors: M
authors: Wenger
authors: Mbarara University of Science and Technology, Mbarara, Uganda.
authors: Mwebesa
authors: M
authors: Bwana
authors: Indiana University School of Medicine, Indianapolis, IN, USA.|AMPATH, Moi University, Eldoret, Kenya.
authors: F Chite
authors: FC
authors: Asirwa
authors: AMPATH, Moi University, Eldoret, Kenya.
authors: Naftali
authors: N
authors: Busakhala
authors: Institute of Human Virology, Abuja, Nigeria.
authors: Emmanuel
authors: E
authors: Oga
authors: Institute of Human Virology, Abuja, Nigeria.
authors: Elima
authors: E
authors: Jedy-Agba
authors: University of Abuja Teaching Hospital, Abuja, Nigeria.
authors: Vivian
authors: V
authors: Kwaghe
authors: National Hospital of Abuja, Abuja, Nigeria.
authors: Kenneth
authors: K
authors: Iregbu
authors: INSERM U897 & ISPED, Université Bordeaux, Bordeaux, France.
authors: Antoine
authors: A
authors: Jaquet
authors: INSERM U897 & ISPED, Université Bordeaux, Bordeaux, France.
authors: Francois
authors: F
authors: Dabis
authors: R4D International, Yaounde, Cameroon.
authors: Habakkuk Azinyui
authors: HA
authors: Yumo
authors: Regional Alliance for Sustainable Development, Kigali, Rwanda.
authors: Jean Claude
authors: JC
authors: Dusingize
authors: Center for Global Health, Massachusetts General Hospital, Boston, MA, USA.
authors: David
authors: D
authors: Bangsberg
authors: Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA.
authors: Kathryn
authors: K
authors: Anastos
authors: Lighthouse Trust Clinic, Lilongwe, Malawi.
authors: Sam
authors: S
authors: Phiri
authors: University of Bern, Bern, Switzerland.
authors: Julia
authors: J
authors: Bohlius
authors: University of Bern, Bern, Switzerland.
authors: Matthias
authors: M
authors: Egger
authors: Indiana University Fairbanks School of Public Health, Indianapolis, USA.
authors: Constantin
authors: C
authors: Yiannoutsos
authors: Indiana University School of Medicine, Indianapolis, IN, USA.
authors: Kara
authors: K
authors: Wools-Kaloustian
authors: University of California, San Francisco, USA.
authors: Jeffrey
authors: J
authors: Martin
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D003695:Delivery of Health Care / Q000191:economics; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications / Q000191:economics / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012514:Sarcoma, Kaposi / Q000150:complications / Q000175:diagnosis* / Q000191:economics / Q000453:epidemiology* / Q000473:pathology