[Estimating cost functions of cancer screening programs provided by municipalities].

ABSTRACT

OBJECTIVE: To estimate cost functions of cancer screening programs for stomach, lung, colorectal, cervical, and breast cancers provided by municipalities and to describe the relationship between the costs and the scale of cancer screening programs. METHODS: Subjects were all the municipalities in Japan. Questionnaires were sent to 3,182 subjects and 1,860 responses were received. Data obtained from questionnaires were the number of persons screened and the total cost of each program in the 1998 fiscal year. A cost function of each program was specified as a linear model, a power model, and a cubic model, and the fitness of each model was estimated. RESULTS: Long-run cost functions of all the cancer screening programs allowed better explanation of the relationship between the number of persons screened and the total cost than short-run cost functions. The average costs of stomach, colorectal, and cervical cancer screening programs increased and the average cost of the lung cancer screening program decreased, as the number of persons screened increased. The cost function of the breast cancer screening program could not be identified. CONCLUSIONS: It is necessary to estimate not only cost functions but also production functions of cancer screening programs using the data related to products, costs, and factors of production to evaluate the efficiency of cancer screening programs.