Interpreting cost analyses of clinical interventions.
OBJECTIVE: In the present era of cost containment, physicians need reliable data about specific interventions. The objectives of this study were to assist practitioners in interpretation of economic analyses and estimation of their own costs of implementing recommended interventions. DATA SOURCES: MEDLINE search from 1966 through 1995 using the text words cost or expense and medical subject heading (MeSH) terms costs and cost analysis, cost control, cost of illness, cost savings, or cost-benefit analysis. STUDY SELECTION: The 4 eligibility criteria were clinical trial with random assignment; health care quality improvement intervention tested; effects measured on the process or outcome of care; and cost calculation mentioned in the report. DATA EXTRACTION: After independent abstraction and after consensus development, financial data were entered into a costing protocol to determine which costs related to the intervention were provided. DATA SYNTHESIS: Of 181 articles, 97 (53.6%) included actual numbers on the costs of the intervention. Of 97 articles analyzed, the most frequently reported cost figures were in the category of operating expenses (direct cost, 61.9%; labor, 42.3%; and supplies, 32.0%). General overhead was not presented in 91 (93.8%) of the 97 studies. Only 14 (14.4%) of the 97 studies mentioned start-up costs. The text word $ in the abstract and the most useful MeSH index term of cost-benefit analysis appeared with nearly equal frequency in the articles that included actual cost data (37.1 % vs 35.1%). Two thirds of articles indexed with the MeSH term cost control did not include cost figures. CONCLUSIONS: Statements regarding cost without substantiating data are made habitually in reports of clinical trials. In clinical trial reports presenting data on expenditures, start-up costs and general overhead are frequently disregarded. Practitioners can detect missing information by placing cost data in a standardized protocol. The costing protocol of this study can help bridge care delivery and economic analyses.