Chen S, Shaheen A, Garber A; Association for Health Services Research. Meeting.
Abstr Book Assoc Health Serv Res Meet. 1998; 15: 175.
900 Blake Wilbur Drive, W0069, Stanford, CA 94305, USA.
RESEARCH OBJECTIVE: Conventional methods for evaluating health outcomes are poorly suited to the analysis of treatments for skin disease. Such diseases can be disfiguring and cause discomfort, but few result in death or significant disability. Commonly used methods for utility assessment are better suited for conditions that cause more severe morbidity. The lack of simple, easily measured endpoints has undoubtably contributed to the lack of cost-effectiveness studies in dermatology. This study assesses utilities and carries out cost-effectiveness and cost-benefit analysis for two common treatments for one of the most common serious skin diseases, psoriasis. The treatments are methotrexate and Goeckerman therapy. Psoriasis is an excellent model for outcome studies in dermatology. It is very prevalent, affecting 1% of United States population, and costly to treat, consuming $1,521,000,000 in 1984. Although not life-threatening, it is a chronic condition that can significantly impact patients' quality of life. STUDY DESIGN: The willingness to pay (WTP) and vertical rating scale methods were used used in a written survey that was given to patients with psoriasis, dermatology faculty and residents, and members of society who did not necessarily have knowledge about psoriasis. Costs for physician and hospital fees, supplies, labs, and medications were obtained from the appropriate departments at Stanford Health Services. In the cost benefit analysis (CBA), the total cost needed to generate each service (or treatment) was subtracted from the WTP. In the benefit outweighed the cost, the service was deemed "worth providing". The WTP responses of each of the three surveyed groups were initially considered separately. The overall population evaluation of the health states was estimated by obtaining weighted averages of the responses from the different sample groups, reflected the disease prevalence (1%) and the prevalence of physicians (0.26%) in the U.S. population. Three cost-effectiveness analysis (CEA) were performed: methotrexate compared to no treatment, Goeckerman compared to new treatment, and methotrexate compared to Goeckerman. Adhering to common practice in the literature, we labeled any ratio exceeding $30,000 per QALY "not cost-effective". Finally, we conducted a sensitivity analysis to assess the impact of the assumed efficacy rates of both therapies. PRINCIPAL FINDINGS: For mild psoriasis, methotrexate and Goeckerman are never cost-beneficial. Only liquid methotrexate is cost-beneficial for moderate psoriasis. For severe psoriasis, the benefits outweigh the costs for both forms of methotrexate. The liquid form is far more cost-beneficial than the tablet form. An annual cost saving of $537 (mild psoriasis), $896 (moderate) and $1433 (severe) can be obtained by using liquid methotrexate instead of the tablet form. In the CEA, Goeckerman and methotrexate are always cost-effective when compared to no treatment. When compared to tablet methotrexate, Goeckerman is only cost-effective in severe psoriasis. Goeckerman is never cost-effective when compared to liquid methotrexate. The sensitivity analysis revealed that for a high methotrexate efficacy rate (82%), Goeckerman is never cost-effectiveness even when compared to liquid methotrexate. For low methotrexate efficacy rates (43%), Goeckerman is cost-effective compared to both tablet and liquid methotrexate for moderate and severe disease. CONCLUSIONS: These findings imply that it is important to obtain more precise estimates of the efficacy of methotrexate in order to determine whether it is cost-effective. Our results indicate that liquid methotrexate is preferred to the other treatments, whether a cost-benefit or a cost-effectiveness criterion is used. In common practice, methotrexate and Goeckerman are not offered for mild psoriasis because topical therapies are effective for this level of disease. For the rare care of recalcitrant mild psoriasis, the weighted average results from the cost-effectiveness analysis would suggest that Goeckerman and methotrexate might be cost-effective alternatives. Generalization of these results to other settings may not be possible because all costs were derived from Stanford University Hospital. Also important are the general limitations of WTP and visual analog scale. In WTP, there is tendency for the subject to be overly focused on the disease presented. Also, subjects are not familiar with identifying dollar amounts for therapies. With the visual analog scale, subjects may rate their preferences too low for non life-threatening disease states. Thus, it may be important to give subjects ample instruction in the preference assessment techniques and to enable them to place the disease in context before surveying them.
Publication Types:
Keywords:
- Cost-Benefit Analysis
- Humans
- Methotrexate
- PUVA Therapy
- Phototherapy
- Psoriasis
- Quality-Adjusted Life Years
- Sensitivity and Specificity
- Treatment Outcome
- Ultraviolet Therapy
- United States
- economics
- therapy
- hsrmtgs
Other ID:
UI: 102234313
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