Preventing HIV in injection drug users: choosing the best mix of interventions for the population

The cost-effectiveness of collegiate recovery programs

OBJECTIVE

To conduct a preliminary cost-effectiveness analysis of collegiate recovery programs in the United States and to create a tailorable cost-effectiveness calculator based on the preliminary cost-effectiveness model.

METHODS

Cost-effectiveness was assessed with a base case, one-way sensitivity analyses, and probabilistic sensitivity analyses for the societal and health systems (institutions of higher education) perspectives, comparing CRPs to treatment as usual. Models were estimated using secondary data sources. A cost-effectiveness calculator was constructed using the models developed for the cost-effectiveness analysis.

RESULTS

CRPs were found to be cost-effective across all models. Institutional and societal models were robust to changes in parameters.

CONCLUSIONS

CRPs are a cost-effective intervention and are cost-saving under certain conditions. A free online calculator developed form this analysis is available to estimate program-specific cost-effectiveness.

A Systematic Review of Simulation Models to Track and Address the Opioid Crisis

The opioid overdose crisis is driven by an intersecting set of social, structural, and economic forces. Simulation models offer a tool to help us understand and address this complex, dynamic, and nonlinear social phenomenon. We conducted a systematic review of the literature on simulation models of opioid use and overdose up to September 2019. We extracted modeling types, target populations, interventions, and findings. Further, we created a database of model parameters used for model calibration, and evaluated study transparency and reproducibility. Of the 1,398 articles screened, we identified 88 eligible articles. The most frequent types of models were compartmental (36%), Markov (20%), system dynamics (16%), and Agent-Based models (16%). Over a third evaluated intervention cost-effectiveness (40%), and another third (39%) focused on treatment and harm reduction services for people with opioid use disorder (OUD). More than half (61%) discussed calibrating their models to empirical data, and 31% discussed validation approaches used in their modeling process. From the 63 studies that provided model parameters, we extracted the data sources on opioid use, OUD, OUD treatment, cessation/relapse, emergency medical services, and mortality parameters. This database offers a tool that future modelers can use to identify potential model inputs and evaluate comparability of their models to prior work. Future applications of simulation models to this field should actively tackle key methodological challenges, including the potential for bias in the choice of parameter inputs, investment in model calibration and validation, and transparency in the assumptions and mechanics of simulation models to facilitate reproducibility.

A Little Planning Goes a Long Way: Multilevel Allocation of HIV Prevention Resources

Background. HIV prevention funds are often allocated by decision makers at multiple levels. High-level decision makers may allocate funds to regions, and regional decision makers then allocate those funds to specific programs. Often, funds are allocated proportionally (e.g., in proportion to HIV incidence) rather than efficiently (i.e., to maximize HIV infections averted). The authors investigate the impact of efficient and proportional allocation methods at 2 different decision levels.

Methods. The authors developed an optimization model of resource allocation at 2 levels—an aggregate upper level and multiple local levels—and considered efficient allocation and allocation proportional to HIV incidence. Using data from 40 U.S. states, they compared 4 strategies for allocating HIV prevention funds.

Results. The greatest health benefit (HIV infections averted) occurred when efficient allocations were made at both levels. When funds were allocated proportionally at the higher level and efficiently at the lower level, the health benefit was about 5% less than when efficient allocations were made at both levels. When funds were allocated efficiently at the higher level and proportionally at the lower level, the health benefit was 15% less than when efficient allocations were made at both levels. The least health benefit (23% less than when efficient allocations were made at both levels) occurred with proportional allocation at both levels.

Conclusions. Efficient allocation only at the higher level cannot overcome poor allocations at lower levels. Moreover, efficient allocation at the lower level is likely to yield greater gains than efficient allocation at the higher level. Thus, upper-level decision makers, such as donor organizations, should develop incentives to promote efficient allocation by lower-level decision makers.

Costs and cost-effectiveness of HIV community services: quantity and quality of studies published 1986-2011

Community services comprise an important part of a country's HIV response. English language cost and cost-effectiveness studies of HIV community services published between 1986 and 2011 were reviewed but only 74 suitable studies were identified, 66% of which were performed in five countries. Mean study scores by continent varied from 42 to 69% of the maximum score, reflecting variation in topics covered and the quality of coverage: 38% of studies covered key and 11% other vulnerable populations - a country's response is most effective and efficient if these populations are identified given they are key to a successful response. Unit costs were estimated using different costing methods and outcomes. Community services will need to routinely collect and analyze information on their use, cost, outcome and impact using standardized costing methods and outcomes. Cost estimates need to be disaggregated into relevant cost items and stratified by severity and existing comorbidities. Expenditure tracking and costing of services are complementary aspects of the health sector 'resource cycle' that feed into a country's investment framework and the development and implementation of national strategic plans.

Non-prescription syringe sales in California: a qualitative examination of practices among 12 local health jurisdictions

Legislation permitting non-prescription syringe sales (NPSS) was passed in 2004 in California as a structural intervention designed to expand access to syringes for injection drug users. As of December 2009, 19 of California's 61 local health jurisdictions (LHJs) have approved policies to authorize pharmacies to sell non-prescription syringes. The legislation faces termination in 2010 if current evaluation efforts fail to demonstrate outcomes defined in the legislation. Using qualitative methods, we examined the systems and procedures associated with implementation; identified facilitators and barriers to implementation among 12 LHJs, and documented the role of public health in initiating and sustaining local programs. We identified consistent activities that led to policy implementation among LHJs and discovered several barriers that were associated with failure to implement local programs. Factors leading to NPSS were public health leadership; an inclusive planning process, marketing the program as a public health initiative; learning from others' efforts, successes, and failures; and identifying acceptable syringe disposal options in advance of program implementation. Health departments that were confronted with political and moral arguments lost momentum and ultimately assigned a lower priority to the initiative citing the loss of powerful public health advocates or a lack of human resources. Additional barriers were law enforcement, elected officials, and pharmacy opposition, and failure to resolve syringe disposal options to the satisfaction of important stakeholders. The lessons learned in this study should provide useful guidance for the remaining LHJs in California without NPSS programs.

A review of the efficacy and effectiveness of harm reduction strategies for alcohol, tobacco and illicit drugs

Harm reduction is both a policy approach and used to describe a specific set of interventions. These interventions aim to reduce the harms associated with drug use. Employing a strict definition of harm reduction, evidence for the efficacy and effectiveness of alcohol, tobacco and illicit drug harm reduction interventions were reviewed. Systematic searches of the published literature were undertaken. Studies were included if they provided evaluation data (pre-post, or control group comparisons). More than 650 articles were included in the review. The majority of the literature concerned illicit drugs. For alcohol, harm reduction interventions to reduce road trauma are well-founded in evidence. Otherwise, there is limited research to support the efficacy and effectiveness of other alcohol harm reduction interventions. For tobacco, the area is controversial but promising new products that reduce the harms associated with smoking are being developed. In the area of illicit drugs there is solid efficacy, effectiveness and economic data to support needle syringe programmes and outreach programmes. There is limited published evidence to date for other harm reduction interventions such as non-injecting routes of administration, brief interventions and emerging positive evidence for supervised injecting facilities. There is sufficient evidence to support the wide-spread adoption of harm reduction interventions and to use harm reduction as an overarching policy approach in relation to illicit drugs. The same cannot be concluded for alcohol or tobacco. Research at a broad policy level is required, especially in light of the failure by many policy makers to adopt cost-effective harm reduction interventions.

S4HARA: System for HIV/AIDS resource allocation

Background

HIV/AIDS resource allocation decisions are influenced by political, social, ethical and other factors that are difficult to quantify. Consequently, quantitative models of HIV/AIDS resource allocation have had limited impact on actual spending decisions. We propose a decision-support System for HIV/AIDS Resource Allocation (S4HARA) that takes into consideration both principles of efficient resource allocation and the role of non-quantifiable influences on the decision-making process for resource allocation.

Methods

S4HARA is a four-step spreadsheet-based model. The first step serves to identify the factors currently influencing HIV/AIDS allocation decisions. The second step consists of prioritizing HIV/AIDS interventions. The third step involves allocating the budget to the HIV/AIDS interventions using a rational approach. Decision-makers can select from several rational models of resource allocation depending on availability of data and level of complexity. The last step combines the results of the first and third steps to highlight the influencing factors that act as barriers or facilitators to the results suggested by the rational resource allocation approach. Actionable recommendations are then made to improve the allocation. We illustrate S4HARA in the context of a primary healthcare clinic in South Africa.

Results

The clinic offers six types of HIV/AIDS interventions and spends US$750,000 annually on these programs. Current allocation decisions are influenced by donors, NGOs and the government as well as by ethical and religious factors. Without additional funding, an optimal allocation of the total budget suggests that the portion allotted to condom distribution be increased from 1% to 15% and the portion allotted to prevention and treatment of opportunistic infections be increased from 43% to 71%, while allocation to other interventions should decrease.

Conclusion

Condom uptake at the clinic should be increased by changing the condom distribution policy from a pull system to a push system. NGOs and donors promoting antiretroviral programs at the clinic should be sensitized to the results of the model and urged to invest in wellness programs aimed at the prevention and treatment of opportunistic infections. S4HARA differentiates itself from other decision support tools by providing rational HIV/AIDS resource allocation capabilities as well as consideration of the realities facing authorities in their decision-making process.

Efficient allocation of resources to prevent HIV infection among injection drug users: the Prevention Point Philadelphia (PPP) needle exchange program

The objective of this study is to determine the allocation of resources within a multi-site needle exchange program (NEP) that achieves the largest possible reduction in new HIV infections at minimum cost. We present a model that relates the number of injection drug user (IDU) clients and the number of syringes exchanged per client to both the costs of the NEP and the expected reduction in HIV infections per unit time. We show that cost-effective allocation within a multi-site NEP requires that sites be located where the density of IDUs is highest, and that the number of syringes exchanged per client be equal across sites. We apply these optimal allocation rules to a specific multi-site needle exchange program, Prevention Point Philadelphia (PPP). This NEP, we find, needs to add 2 or 3 new sites in neighborhoods with the highest density of IDU AIDS cases, and to increase its total IDU client base by about 28%, from approximately 6400 to 8200 IDU clients. The case-study NEP also needs to increase its hours of operation at two existing sites, where the number of needles distributed per client is currently sub-optimal, by 50%. At the optimal allocation, the estimated cost per case of HIV averted would be dollar 2800 (range dollar 2300-dollar 4200). Such a favorable cost-effectiveness ratio derives primarily from PPP's low marginal costs per distributed needle.

Improved allocation of HIV prevention resources: using information about prevention program production functions

To allocate HIV prevention resources effectively, it is important to have information about the effectiveness of alternative prevention programs as a function of expenditure. We refer to this relationship as the "production function" for a prevention program. Few studies of HIV prevention programs have reported this relationship. This paper demonstrates the value of such information. We present a simple model for allocating HIV prevention resources, and apply the model to an illustrative HIV prevention resource allocation problem. We show that, without sufficient information about prevention program production functions, suboptimal decisions may be made. We show that epidemiologic data, such as estimates of HIV prevalence or incidence, may not provide enough information to support optimal allocation of HIV prevention resources. Our results suggest that good allocations can be obtained based on fairly basic information about prevention program production functions: an estimate of fixed cost plus a single estimate of cost and resulting risk reduction. We find that knowledge of production functions is most important when fixed cost is high and/or when the budget is a significantly constraining factor. We suggest that, at the minimum, future data collection on prevention program effectiveness should include fixed and variable cost estimates for the intervention when implemented at a "typical" level, along with a detailed description of the intervention and detailed description of costs by category.