[Recent progress of epidemiological studies on intractable diseases in Japan]

Since 1972, the Ministry of Health and Welfare of the Japanese Government has been promoting researches on the etiology of and treatment for so-called intractable diseases of unknown causes for which no specific medical treatment is established. The Research Committee of the Epidemiology of Intractable Diseases was first organized in 1976. The committee has continuously undertaken researches on the epidemiology of these diseases. The paper shows examples of the results of the research projects of the committee. The frequency and distribution of the patients with intractable diseases were estimated by the statistics of patients receiving financial subsidies, national patient surveys and nationwide hospital surveys. Descriptive epidemiology of examples of the diseases are shown. Case-control studies for selected diseases have been conducted by the Research Committee with the cooperation of health centers and university hospitals to which members of the committee belonged. A few examples are given in this report. Pathologists and epidemiologists are exploring the possibility of applying autopsy registration data to epidemiological studies. Examples of such studies are also given.