Mobile HIV screening in Cape Town, South Africa: clinical impact, cost and cost-effectiveness.
BACKGROUND
Mobile HIV screening may facilitate early HIV diagnosis. Our objective was to examine the cost-effectiveness of adding a mobile screening unit to current medical facility-based HIV testing in Cape Town, South Africa.


RESULTS
We used the Cost Effectiveness of Preventing AIDS Complications International (CEPAC-I) computer simulation model to evaluate two HIV screening strategies in Cape Town: 1) medical facility-based testing (the current standard of care) and 2) addition of a mobile HIV-testing unit intervention in the same community. Baseline input parameters were derived from a Cape Town-based mobile unit that tested 18,870 individuals over 2 years: prevalence of previously undiagnosed HIV (6.6%), mean CD4 count at diagnosis (males 423/µL, females 516/µL), CD4 count-dependent linkage to care rates (males 31%-58%, females 49%-58%), mobile unit intervention cost (includes acquisition, operation and HIV test costs, $29.30 per negative result and $31.30 per positive result). We conducted extensive sensitivity analyses to evaluate input uncertainty. Model outcomes included site of HIV diagnosis, life expectancy, medical costs, and the incremental cost-effectiveness ratio (ICER) of the intervention compared to medical facility-based testing. We considered the intervention to be "very cost-effective" when the ICER was less than South Africa's annual per capita Gross Domestic Product (GDP) ($8,200 in 2012). We projected that, with medical facility-based testing, the discounted (undiscounted) HIV-infected population life expectancy was 132.2 (197.7) months; this increased to 140.7 (211.7) months with the addition of the mobile unit. The ICER for the mobile unit was $2,400/year of life saved (YLS). Results were most sensitive to the previously undiagnosed HIV prevalence, linkage to care rates, and frequency of HIV testing at medical facilities.


CONCLUSIONS
The addition of mobile HIV screening to current testing programs can improve survival and be very cost-effective in South Africa and other resource-limited settings, and should be a priority.
Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Harvard University Center for AIDS Research (CFAR), Boston, Massachusetts, United States of America.
Ingrid V
IV
Bassett
Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
Darshini
D
Govindasamy
Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
Alison S
AS
Erlwanger
Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
Emily P
EP
Hyle
Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Katharina
K
Kranzer
Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
Nienke
N
van Schaik
The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts, United States of America ; Tufts Clinical and Translational Science Institute, Tufts University, Boston, Massachusetts, United States of America.
Farzad
F
Noubary
Department of Health Policy and Management, Yale School of Public Health, New Haven, Connecticut, United States of America.
A David
AD
Paltiel
Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa ; Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
Robin
R
Wood
Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Harvard University Center for AIDS Research (CFAR), Boston, Massachusetts, United States of America ; Division of Infectious Disease, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
Rochelle P
RP
Walensky
Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Harvard University Center for AIDS Research (CFAR), Boston, Massachusetts, United States of America ; Departments of Biostatistics and Epidemiology, Boston University School of Public Health, Boston, Massachusetts, United States of America ; Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
Elena
E
Losina
Desmond Tutu HIV Centre, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
Linda-Gail
LG
Bekker
Division of Infectious Disease, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Division of General Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Medical Practice Evaluation Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America ; Harvard University Center for AIDS Research (CFAR), Boston, Massachusetts, United States of America ; Departments of Biostatistics and Epidemiology, Boston University School of Public Health, Boston, Massachusetts, United States of America ; Department of Health Policy and Management, Harvard School of Public Health, Boston, Massachusetts, United States of America.
Kenneth A
KA
Freedberg
D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000517:prevention & control*; D000328:Adult; D044966:Anti-Retroviral Agents / Q000191:economics / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D003362:Cost-Benefit Analysis / Q000191:economics; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D017048:Health Care Costs / Q000706:statistics & numerical data; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods*; D008952:Mobile Health Units; D017063:Outcome Assessment, Health Care / Q000191:economics; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology; D016019:Survival Analysis; D055815:Young Adult
D044966:Anti-Retroviral Agents