Cost effectiveness of prophylaxis for opportunistic infections in AIDS. An overview and methodological discussion

Cost-Effectiveness of HRSA's Ryan White HIV/AIDS Program?

BACKGROUND

With an annual budget of more than $2 billion, the Health Resources and Services Administration's Ryan White HIV/AIDS Program (RWHAP) is the third largest source of public funding for HIV care and treatment in the United States, yet little analysis has been done to quantify the long-term public health and economic impacts of the federal program.

METHODS

Using an agent-based, stochastic model, we estimated health care costs and outcomes over a 50-year period in the presence of the RWHAP relative to those expected to prevail if the comprehensive and integrated system of medical and support services funded by the RWHAP were not available. We made a conservative assumption that, in the absence of the RWHAP, only uninsured clients would lose access to these medical and support services.

RESULTS

The model predicts that the proportion of people with HIV who are virally suppressed would be 25.2 percentage points higher in the presence of the RWHAP (82.6 percent versus 57.4 percent without the RWHAP). The number of new HIV infections would be 18 percent (190,197) lower, the number of deaths among people with HIV would be 31 percent (267,886) lower, the number of quality-adjusted life years would be 2.7 percent (5.6 million) higher, and the cumulative health care costs would be 25 percent ($165 billion) higher in the presence of the RWHAP relative to the counterfactual. Based on these results, the RWHAP has an incremental cost-effectiveness ratio of $29,573 per quality-adjusted life year gained compared with the non-RWHAP scenario. Sensitivity analysis indicates that the probability of transmitting HIV via male-to-male sexual contact and the cost of antiretroviral medications have the largest effect on the cost-effectiveness of the program.

CONCLUSIONS

The RWHAP would be considered very cost-effective when using standard guidelines of less than the per capita gross domestic product of the United States. The results suggest that the RWHAP plays a critical and cost-effective role in the United States' public health response to the HIV epidemic.

Building a Successful Infection Prevention Program: Key Components, Processes, and Economics

Infection control is the discipline responsible for preventing health care-associated infections (HAIs) and has grown from an anonymous field, to a highly visible, multidisciplinary field of incredible importance. There has been increasing focus on prevention rather than control of HAIs. Infection prevention programs (IPPs) have enormous scope that spans multiple disciplines. Infection control and the prevention and elimination of HAIs can no longer be compartmentalized. This article discusses the structure and responsibilities of an IPP, the regulatory pressures and opportunities that these programs face, and how to build and manage a successful program.

HIV Treatment in Resource-Limited Environments: Treatment Coverage and Insights

BACKGROUND

The effects of antiretroviral treatment on the HIV epidemic are complex. HIV-infected individuals survive longer with treatment, but are less likely to transmit the disease. The standard coverage measure improves with the deaths of untreated individuals and does not consider the fact that some individuals may acquire the disease and die before receiving treatment, making it susceptible to overestimating the long-run performance of antiretroviral treatment programs.

OBJECTIVE

The objective was to propose an alternative coverage definition to better measure the long-run performance of HIV treatment programs.

METHODS

We introduced cumulative incidence-based coverage as an alternative to measure an HIV treatment program's success. To numerically compare the definitions, we extended a simulation model of HIV disease and treatment to represent a dynamic population that includes uninfected and HIV-infected individuals. Also, we estimated the additional resources required to implement various treatment policies in a resource-limited setting.

RESULTS

In a synthetic population of 600,000 people of which 44,000 (7.6%) are infected, and eligible for treatment with a CD4 count of less than 500 cells/mm(3), assuming a World Health Organization (WHO)-defined coverage rate of 50% of eligible people, and treating these individuals with a single treatment regimen, the gap between the current WHO coverage definition and our proposed one is as much as 16% over a 10-year planning horizon.

CONCLUSIONS

Cumulative incidence-based definition of coverage yields a more accurate representation of the long-run treatment success and along with the WHO and other definitions of coverage provides a better understanding of the HIV treatment progress.

Building a successful infection prevention program: key components, processes, and economics

Infection control is the discipline responsible for preventing nosocomial infections. There has been an increasing focus on prevention rather than control of hospital-acquired infections. Individuals working in infection control have seen their titles change from infection control practitioner to infection control professional and most recently to infection preventionist (IP), emphasizing their critical role in protecting patients. The responsibilities of IPs span multiple disciplines including medicine, surgery, nursing, occupational health, microbiology, pharmacy, sterilization and disinfection, emergency medicine, and information technology. This article discusses the structure and responsibilities of an infection control program and the regulatory pressures and opportunities the program faces.

Treatment for primary HIV infection: projecting outcomes of immediate, interrupted, or delayed therapy

With limited data available on the optimal treatment of primary HIV infection, disease modeling can be used to project clinical outcomes and inform decision makers. The authors developed a simulation model to evaluate the clinical outcomes and life expectancy projections for three primary HIV infection treatment strategies: 1) continuous antiretroviral therapy (ART) initiated at CD4 count <350 cells/mm(3); 2) continuous ART initiated immediately on diagnosis of primary HIV infection; and 3) ART initiated on diagnosis followed by structured treatment interruption. Projected life expectancies for the three strategies were 23.92, 24.46, and 26.07 years, respectively. The impact of key variables was assessed in sensitivity analysis, with the structured treatment interruption strategy remaining the most effective over a broad range of inputs. The immunologic benefit associated with immediate therapy and the potential for antiretroviral resistance due to structured treatment interruption have the most important impact on the optimal strategy. Based on current data, immediate treatment on diagnosis of primary HIV infection followed by structured treatment interruption will likely yield the best outcome. These results can assist decision makers and those planning clinical trials in defining evidence-based performance measures for primary HIV infection treatment and future trials.

Remarks on the role of economic modeling

BACKGROUND

Despite the growing scholarly acceptance of quantitative evaluation methods, modelers still struggle to define an appropriate role for their work at the decision-making level.

GOAL

To make observations about the policy relevance of mathematical and economic policy modeling in HIV and sexually transmitted disease prevention and treatment.

RESULTS

The debate is framed within the context of the inevitability of decision making. Viewed in this light, models can inform choices between competing alternatives by leveraging existing information, integrating data from multiple sources, addressing "what if" questions, evaluating future scenarios, and providing a uniform metric for evaluation.

CONCLUSIONS

The goal of model-based evaluation should not be to supplant the decision maker, but rather to redefine the terms of the debate using quantitative methods that make the beliefs and values that lie at the heart of all difficult choices explicit.

Irinotecan in second-line treatment of metastatic colorectal cancer: improved survival and cost-effect compared with infusional 5-FU

In a recent multicentre, randomised, controlled, open-label study (Rougier and colleagues, Lancet 1998, 352, 1407-1412), irinotecan significantly increased survival without any deterioration in quality of life compared with best-estimated infusional 5-fluorouracil (5-FU) therapy in the setting of second-line treatment for metastatic colorectal cancer. The aim of the cost-effectiveness analysis reported here was to compare the economic implications, from a U.K. perspective, of replacing 5-FU therapy [either as a single agent (Lokich regimen, B2) or in combination with folinic acid (de Gramont regimen, B1, or AIO regimen, B3)] with irinotecan as second-line therapy for metastatic colorectal cancer. Resource utilisation data collected prospectively during the study, supplemented by both a questionnaire to investigators and local expert clinical opinion, were used as a basis for estimating cumulative drug dosage, chemotherapy administration and treatment of complications. Drug acquisition costs were derived from the British National Formulary (March 1998), and unit costs for clinical consultation and services were derived from relevant 1996/1997 cost databases. Although cumulative drug acquisition costs per patient were higher with irinotecan than with infusional 5-FU therapy, these were at least partially offset by lower cumulative costs per patient associated with administration of therapy and treatment of complications in the irinotecan arm than in the 5-FU arm. Based on the incremental costs per life year gained (LYG), irinotecan was considered to be cost-effective by commonly accepted criteria compared with either the B1 or B2 regimens. Irinotecan was cost-saving compared with the B3 regimen (that is significant survival gain and a reduction in costs). Thus, not only is there strong evidence for the use of irinotecan as standard second-line therapy in metastatic colorectal cancer,but the results of this prospective economic evaluation have shown that irinotecan also represents good value for money in this clinical setting.