A published mathematical transmission model was used to assess the dynamics of HIV (Anderson, et al. 1991, see 'Other Publications of Related Interest' below for bibliographic details). The time horizon was the lifetime of the patient. The authors reported that a societal perspective was adopted.
The clinical data were from published studies and reports, or assumed by the authors, based on the literature or personal communication with experts. Much of the data came from the needle and syringe programme in Yunnan province. The main estimate of effectiveness was the probability of HIV transmission per injection with a contaminated syringe. This was estimated from eight published studies.
Monetary benefit and utility valuations:
Measure of benefit:
The measures of benefit were the number of HIV infections averted and disability-adjusted life-years (DALYs).
The direct costs were those of the needle and syringe programme, which included syringes, the infrastructure, personnel, marketing, and recurring service costs, as well as viral load tests, cluster of differentiation (CD4) load tests, provision of antiretroviral therapy, herbal treatments, and treatment for opportunistic infections. The costs were from published studies and reports. All costs were reported in US $, and future costs were discounted at an annual rate of 3%. The price year was 2009.
Analysis of uncertainty:
A sensitivity analysis was presented by evaluating the cost-effectiveness of needle and syringe programmes over the period from 2002 to 2008 rather than over a lifetime. Different scaling factors were evaluated; the total intravenous drug user population was assumed to be 2.5 or four times the number of registered intravenous drug users in Yunnan, China.