Taking ART to scale: determinants of the cost and cost-effectiveness of antiretroviral therapy in 45 clinical sites in Zambia

• Published in: PloS one Vol. 7; no. 12; p. e51993
• Main Authors: Marseille, Elliot, Giganti, Mark J, Mwango, Albert, Chisembele-Taylor, Angela, Mulenga, Lloyd, Over, Mead, Kahn, James G, Stringer, Jeffrey S A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 20.12.2012; Public Library of Science (PLoS)
• Subjects: Acquired immune deficiency syndrome; AIDS; Anti-HIV Agents - economics; Anti-HIV Agents - therapeutic use; Antiretroviral agents; Antiretroviral drugs; Antiretroviral therapy; Antiretroviral Therapy, Highly Active - economics; Arthritis; CD4 antigen; Clinics; Communicable diseases; Cost analysis; Cost estimates; Cost-Benefit Analysis; Costs; Cotrimoxazole; Delivery of Health Care - economics; Disease prevention; Drug resistance; Drug therapy; Economic aspects; Economies of scale; Health aspects; Health facilities; Highly active antiretroviral therapy; HIV; HIV Infections - drug therapy; HIV Infections - economics; HIV Infections - prevention & control; HIV patients; Human immunodeficiency virus; Humans; Infectious diseases; Laboratories; Medical research; Medicine; Patients; Pharmacoeconomics; Private sector; Prophylaxis; Public sector; Regression analysis; Rural areas; Tuberculosis; Variation; Zambia; Zambia; San Francisco California; California; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0051993

We estimated the unit costs and cost-effectiveness of a government ART program in 45 sites in Zambia supported by the Centre for Infectious Disease Research Zambia (CIDRZ). We estimated per person-year costs at the facility level, and support costs incurred above the facility level and used multiple regression to estimate variation in these costs. To estimate ART effectiveness, we compared mortality in this Zambian population to that of a cohort of rural Ugandan HIV patients receiving co-trimoxazole (CTX) prophylaxis. We used micro-costing techniques to estimate incremental unit costs, and calculated cost-effectiveness ratios with a computer model which projected results to 10 years. The program cost $69.7 million for 125,436 person-years of ART, or $556 per ART-year. Compared to CTX prophylaxis alone, the program averted 33.3 deaths or 244.5 disability adjusted life-years (DALYs) per 100 person-years of ART. In the base-case analysis, the net cost per DALY averted was $833 compared to CTX alone. More than two-thirds of the variation in average incremental total and on-site cost per patient-year of treatment is explained by eight determinants, including the complexity of the patient-case load, the degree of adherence among the patients, and institutional characteristics including, experience, scale, scope, setting and sector. The 45 sites exhibited substantial variation in unit costs and cost-effectiveness and are in the mid-range of cost-effectiveness when compared to other ART programs studied in southern Africa. Early treatment initiation, large scale, and hospital setting, are associated with statistically significantly lower costs, while others (rural location, private sector) are associated with shifting cost from on- to off-site. This study shows that ART programs can be significantly less costly or more cost-effective when they exploit economies of scale and scope, and initiate patients at higher CD4 counts.