Background Avahan is a large-scale, HIV preventive intervention, targeting high-risk populations in south India. We assessed the cost-eff ectiveness of Avahan to inform global and national funding institutions who are considering investing in worldwide HIV prevention in concentrated epidemics. Methods We estimated cost eff ectiveness from a programme perspective in 22 districts in four high-prevalence states. We used the UNAIDS Costing Guidelines for HIV Prevention Strategies as the basis for our costing method, and calculated effect estimates using a dynamic transmission model of HIV and sexually transmitted disease transmission that was parameterised and fi tted to locally observed behavioural and prevalence trends. We calculated incremental cost-eff ective ratios (ICERs), comparing the incremental cost of Avahan per disability-adjusted life-year (DALY) averted versus a no-Avahan counterfactual scenario. We also estimated incremental cost per HIV infection averted and incremental cost per person reached. Findings Avahan reached roughly 150000 high-risk individuals between 2004 and 2008 in the 22 districts studied, at a mean cost per person reached of US$327 during the 4 years. This reach resulted in an estimated 61000 HIV infections averted, with roughly 11 000 HIV infections averted in the general population, at a mean incremental cost per HIV infection averted of $785 (SD 166). We estimate that roughly 1 million DALYs were averted across the 22 districts, at a mean incremental cost per DALY averted of $46 (SD 10). Future antiretroviral treatment (ART) cost savings during the lifetime of the cohort exposed to HIV prevention were estimated to be more than $77 million (compared with the slightly more than $50 million spent on Avahan in the 22 districts during the 4 years of the study). Interpretation This study provides evidence that the investment in targeted HIV prevention programmes in south India has been cost eff ective, and is likely to be cost saving if a commitment is made to provide ART to all that can benefit from it. Policy makers should consider funding and sustaining large-scale targeted HIV prevention programmes in India and beyond.
Bibliographical noteFunding Information:
Our results confirm previous evidence from national models and pilot studies ). Our estimates of incremental cost per DALY averted are substantially below the willingness-to-pay threshold and within the ranges achieved by other HIV preventive interventions. 9,10 suggesting that HIV prevention programmes targeted at high-risk groups at scale are cost effective ( panel 8,22 Our findings therefore suggest that HIV prevention interventions focused on high-risk groups are good value for money in India and similar settings. Our estimates of incremental cost per DALY averted are higher than those previously estimated for India. 11 This difference is, to a large extent, due to the fact that we measured costs incurred above the NGO level in our analysis. 7 These costs are important to consider because they are incremental and are likely to be a substantial component of the effort to scale up HIV prevention rapidly, especially in any setting where NGO capacity is weak. We also found higher numbers of clients per FSW and more baseline condom use than in previous studies, 10 and a slower rate of increase in condom use, possibly reflecting the longer start-up period of larger scale programmes. 5 Finally, we also chose a more conservative counterfactual than in previous studies. Although our estimates of the incremental cost per DALY averted are higher than previous studies, the greater precision surrounding our estimates (primarily due to our extensive cost data collection, the fitting of the model, and use of in-depth local data from high-quality surveys designed to parameterise the model), allows us to be more certain that targeted HIV prevention in India has been cost effective. The remaining uncertainty we noted is largely due to the wide credibility interval we noted around the effect estimates. This stems from the challenges of accurately mapping high-risk populations; the absence of baseline data for both condom use and HIV prevalence, which might be unavoidable in real-life evaluation of marginalised populations 32 and which meant that condom trends were derived with additional uncertainty; and the relatively wide range of epidemic trajectories that could fit prevalence data at two or three timepoints. We also noted a substantial variation in costs, effect, and cost-effectiveness by district. Although the few study sites means that statistical exploration of the drivers of this variation is challenging, complementary analyses of the costs from all Avahan districts show that both programme scope and scale are key drivers of cost variation between districts. 7 Specifically, ongoing analysis suggests that the way in which programmes contract out STI services, the involvement of the community, and the type of FSW reached might explain the variation of costs between districts. We also note substantial economies of scale (with no diseconomies observed at high levels of coverage). HIV prevention programmes therefore have to carefully consider the size of the NGO contracted, weighing the benefits of small community NGOs against the lower costs of larger NGOs that can benefit from economies of scale. Moreover, in our modelling work, we have identified several contextual factors that are likely to drive differences in impact at the district level, such as the baseline level of condom use, the presence of other targeted HIV interventions and the size of the sex worker population. 6 The effect of these contextual factors means that care should also be taken before generalisation of our findings to other settings; these explanatory factors are also likely to vary by the stage of HIV epidemic and setting. Although this study confirms that HIV prevention at scale can be highly cost effective and potentially cost saving, several unresolved questions remain regarding the most affordable model of scale-up. The costs shown here represent 22 districts, but are part of a wider costing study that has collected costs from 64 districts in India. From this broader costing study, we estimate that the annual cost of sustaining Avahan across four states is around $35 million. 7 This is a sizeable sum, but remains a small proportion of the national health budget of around $5 billion per year. 7 However, in view of recent budget cuts and the substantial disease burden in India, questions are being raised as to whether the Avahan HIV prevention model, with a high level of intensity support and community involvement, is the most cost-effective way forward; and whether it is possible to achieve the same effect with a lower scale or reduced scope of services. Further work is ongoing with the dataset we present to explore these questions, in particular to examine the effect of increased investment in community mobilisation on HIV prevention programme cost-effectiveness, and threshold levels of coverage required to achieve a satisfactory effect. Finally, important limitations should be noted that affect both our economic evaluation and those of most previous studies. First, our study excluded any economic welfare benefit to the recipients of HIV programmes by exclusion of other health and economic benefits, such as DALY gains from reductions in violence, reductions in the number of cases of other STIs, reduced orphanhood from HIV, and other welfare gains for the increased empowerment of high-risk group members. Second, we excluded the costs incurred by the high-risk group members themselves, such as the opportunity cost of time spent with peer educators. Although the exclusion of costs incurred by high-risk group members could mean that we have overestimated cost-effectiveness, these costs are likely to be small in view of the outreach nature of the Avahan programme. Third, compared with other Avahan districts, the 22 districts included in this study were more likely to have a pre-existing intervention and thus effect and cost-effectiveness might be lower than in other districts. Finally, our estimates of ART cost only included first-line treatment, so are likely to underestimate the true future resource requirements of ART. This study provides evidence, with local data from a programme delivered to scale, that the large investment in targeted HIV prevention programmes made in India during the past decade has not only had an effect, but has been cost effective. To our knowledge, our findings are the best evidence so far to suggest that those responsible for HIV prevention programme development should consider sustaining and expanding investment in such programmes in India and beyond as a priority strategy for combating HIV. For WHO life expectancy tables see http://apps.who.int/gho/data/view.main.60740?lang=en' Contributors All authors were involved in aspects of study design, data collection, and/or analysis of data used in the report. AV, MP, SC, and LG wrote the first draft of the report. All authors contributed to subsequent drafts of the report and reviewed the final version before submission. Declaration of interests MC-B reports grants and personal fees from the Bill & Melinda Gates Foundation both during the conduct of the study and outside of the submitted work. AV declares no competing interests. SM reports grants and personal fees from the Bill & Melinda Gates Foundation during the conduct of the study, grants and personal fees from Bill & Melinda Gates Foundation, and grants from Canadian Institutes of Health Research, outside the submitted work. SC reports grants from the Bill & Melinda Gates Foundation, grants from International Development Research Centre, and a scholarship amount for an International Masters Degree in Health and Pharmacoeconomics from HIV Research Trust UK during the conduct of the study. MA reports grants from the Bill & Melinda Gates Foundation during the conduct of the study; and grants from the Bill & Melinda Gates Foundation, Canadian Institutes of Health Research, Canadian Foundation for AIDS Research, and International Development Research Centre outside the submitted work. MP declares no competing interests. LG reports grants from London School of Hygiene & Tropical Medicine during the conduct of the study; grants from the European Developing Countries Trial Programme, from the Australian Department for Foreign Affairs and Trade, from the Department for International Development, UK, from the National Institute for Health Research, England outside the submitted work; has a grant pending from University of New South Wales; and has previously published work on the costs of government funded HIV prevention for vulnerable groups in India, funded by the Wellcome Trust. JB received a grant and personal fees from the Bill & Melinda Gates Foundation during the conduct of the study. PV and CML declare no competing interests. GS reports grants from Bill & Melinda Gates Foundation during the conduct of the study. Charme India Group Michel Alary, Janet Bradley, Sushena Reza-Paul (Centre de Recherche du CHU Universitaire de Québec, QC, Canada); Michel Alary, Catherine M Lowndes (Département de Médecine Sociale et Préventive, Université Laval, Québec, QC, Canada); Catherine M Lowndes, Lilani Kumaranayake, Peter Vickerman, Charlotte Watts (London School of Hygiene & Tropical Medicine, London, UK); Marie-Claude Boily (Imperial College, London, UK); James Blanchard, Stephen Moses, Banadakoppa M Ramesh, Sushena Reza-Paul (University of Manitoba, Winnipeg, MB, Canada); Shajy Isac, Stephen Moses, Banadakoppa M Ramesh, Reynold Washington (Karnataka Health Promotion Trust, Bangalore, India); Reynold Washington (St John's Research Institute, Bangalore India); and Peter Vickerman (Department of Social and Community Medicine, University of Bristol, Bristol, UK). Acknowledgments This research was funded by the Bill & Melinda Gates Foundation. The views expressed herein are those of the authors and do not necessarily reflect the official policy or position of the Bill & Melinda Gates Foundation. The authors are grateful for all the staff at the Karnataka Health Promotion Trust, Family Health International, National AIDS Research Institute, and Public Health Foundation of India. The authors are also grateful to Annie Tangri for her work providing us with programme data; and the support of Padma Chandrasekaran, Virginia Loo, Gina Dallabetta, and James Moore. Finally, the authors are grateful to the members of the Avahan Evaluation Advisory Group, convened by WHO, for their valuable advice and guidance on the design and implementation of the evaluation of the Avahan programme.
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