[Epidemiology of primary pulmonary hypertension in Japan].

Primary pulmonary hypertension(PPH) is a progressive disease of unknown etiology with poor prognosis. Recent epidemiological studies in Japan have shown that there are 230 patients (95% confidence interval: 200-260) with mean age of 41.8 +/- 18.5 years old, female to male ratio of 1.72: 1 and their median survival time was 69.0 months. At a later time, the clinically effective modalities such as lung transplantation and prostaglandin I2 for PPH were available in Japan. In 1999, the Ministry of Health and Welfare of Japan approved PPH as a objective disease of therapeutic study. Once patient is approved as PPH based on the personal clinical inquiry, Doctor's fee will be paid at the public government. This system will promote earlier and more accurate diagnosis in PPH patients and will clarify more reliable clinico-epidemiological figure of PPH in a whole territory of Japan.