Health and Economic Impacts of an HIV Intervention in Out of Treatment Substance Abusers: Evidence from a Dynamic Model

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.

Conceptualizing a model: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force-2

The appropriate development of a model begins with understanding the problem that is being represented. The aim of this article is to provide a series of consensus-based best practices regarding the process of model conceptualization. For the purpose of this series of papers, the authors consider the development of models whose purpose is to inform medical decisions and health-related resource allocation questions. They specifically divide the conceptualization process into two distinct components: the conceptualization of the problem, which converts knowledge of the health care process or decision into a representation of the problem, followed by the conceptualization of the model itself, which matches the attributes and characteristics of a particular modeling type to the needs of the problem being represented. Recommendations are made regarding the structure of the modeling team, agreement on the statement of the problem, the structure, perspective and target population of the model, and the interventions and outcomes represented. Best practices relating to the specific characteristics of model structure, and which characteristics of the problem might be most easily represented in a specific modeling method, are presented. Each section contains a number of recommendations that were iterated among the authors, as well as the wider modeling taskforce, jointly set up by the International Society for Pharmacoeconomics and Outcomes Research and the Society for Medical Decision Making.

Conceptualizing a model: a report of the ISPOR-SMDM Modeling Good Research Practices Task Force--2

The appropriate development of a model begins with understanding the problem that is being represented. The aim of this article was to provide a series of consensus-based best practices regarding the process of model conceptualization. For the purpose of this series of articles, we consider the development of models whose purpose is to inform medical decisions and health-related resource allocation questions. We specifically divide the conceptualization process into two distinct components: the conceptualization of the problem, which converts knowledge of the health care process or decision into a representation of the problem, followed by the conceptualization of the model itself, which matches the attributes and characteristics of a particular modeling type with the needs of the problem being represented. Recommendations are made regarding the structure of the modeling team, agreement on the statement of the problem, the structure, perspective, and target population of the model, and the interventions and outcomes represented. Best practices relating to the specific characteristics of model structure and which characteristics of the problem might be most easily represented in a specific modeling method are presented. Each section contains a number of recommendations that were iterated among the authors, as well as among the wider modeling taskforce, jointly set up by the International Society for Pharmacoeconomics and Outcomes Research and the Society for Medical Decision Making.

A literature review of reporting standards of HIV progression models

OBJECTIVE

We conducted a systematic review of HIV progression models to identify the mathematical structures used, the main research questions and key model aspects in terms of quality and robustness.

METHODS

We searched for articles published before February 2009 that described models of HIV progression in humans. We included two strategies of search with and without MeSH terms. We classified the models by their mathematical structure and research question. We created a checklist of desirable features of the models, reviewed and classified the articles to inform our conclusions.

RESULTS

Among 3491 articles found, 93 met the inclusion criteria. Among the selected articles, 60 used transition models, 25 applied differential equations, and eight had other structures. We did not find a relation between the type of question explored and the modeling method used. None of the studies complied with the complete set of items in the checklist, but 6.5% cover at least 90% of them.

CONCLUSION

There is an enormous heterogeneity of HIV modeling exercises in terms of methods used and topics addressed, as well as in the presentation of key aspects of the articles in terms of quality and robustness.

A Systematic Review of Cost-Utility Analyses in HIV/AIDS: Implications for Public Policy

Objectives . To determine whether gaps exist in published cost-utility analyses as measured by their coverage of topics addressed in current HIV guidelines from the Department of Health and Human Services (DHHS). Design . A systematic review of US-based cost-effectiveness analyses of HIV/AIDS prevention and management strategies, based on original, published research. Methods . Predefined criteria were used to identify all analyses pertaining to prevention and management of HIV/AIDS; information was collected on type of strategy, patient demographics, study perspective, quality of the study, effectiveness measures, costs, and cost-effectiveness ratios. Results . One hundred and six studies were identified; 62 described strategies for averting new HIV infections, and 44 dealt with managing persons who are HIV positive. The quality of studies was generally high, but gaps were found in all studies. Especially common were omissions in reporting data abstraction methodology and discussions of direction and magnitude of potential biases. Among the 22 most highly rated papers (score of 90 or higher), only 1 was cited in the guidelines, and 3 papers reported on interventions that were superseded by newer approaches. Using a $100,000 threshold, the guidelines usually endorsed interventions found to be cost-effective. Exceptions included recommending postexposure prophylaxis (PEP) for populations in which PEP is unlikely to be cost-effective and not recommending primary resistance testing in treatment-naive persons, although the intervention was reported to have a cost-effectiveness ratio of less than $50,000. Conclusions . Despite an abundant literature on the cost-utility of HIV/AIDS-targeted strategies, guidelines cite relatively few of these papers, and gaps exist regarding assessments of some strategies and special populations.

A linear programming model for allocating HIV prevention funds with state agencies: a pilot study

Given the initiatives to improve resource allocation decisions for HIV prevention activities, a linear programming model was designed specifically for use by state and local decision-makers. A pilot study using information from the state of Florida was conducted and studied under a series of scenarios depicting the impact of common resource allocation constraints. Improvements over the past allocation strategy in the number of potential infections averted were observed in all scenarios with a maximal improvement of 73%. When allocating limited resources, policymakers must balance efficiency and equity. In this pilot study, the optimal allocation (i.e., most-efficient strategy) would not distribute resources in an equitable manner. Instead, only 12% of at-risk people would receive prevention funds. We find that less efficient strategies, where 58% fewer infections are averted, result in significantly more equitable allocations. This tool serves as a guide for allocating funds for prevention activities.

Adherence to HIV treatment among IDUs and the role of opioid substitution treatment (OST)

In the era of highly effective anti-retroviral therapy (ART), data show a significant difference in treatment outcomes between injecting drug users (IDUs) and non-IDUs. Factors that may contribute to suboptimal treatment outcomes in IDUs include delayed access to ART, competing comorbid diseases, psychosocial barriers and poor long-term adherence to ART. This review describes and compares several studies on adherence to ART and its correlates in HIV-infected individuals in general, then IDUs and finally those IDUs on opioid substitution treatment (OST). It highlights how ongoing drug use or OST can modify the pattern of these correlates. The aim is to extend all the experience acquired from these studies in order to optimise both access to care and adherence in those countries where HIV infection is mainly driven by IDUs and where ART and OST are only starting to be scaled up. The role of OST in fostering access to care and adherence to ART together with the promising results achieved to date using modified directly observed therapy (DOT) programs for patients taking methadone, allow us to emphasize the efficacy of a comprehensive care model which integrates substance dependence treatment, psychiatric treatment, social services, and medical treatment. The review concludes by suggesting areas of future research targeted at improving the understanding of both the role of perceived toxicity and patient-provider relationship for patients on ART and OST.