A study on the survival rates for patients and suspected patients with Itai-itai disease

A follow-up study was carried out from January 1967 to December 1986 on 148 patients with Itai-itai disease, 130 suspected patients (persons requiring observation), and 212 controls who were living in the same community as patients with Itai-itai disease. The relative survival rates for the three groups were calculated from a life expectancy table. Except for 1973 data, comparison of the annual data from 1968 to 1986 showed that the relative survival rates in the patient group were significantly lower than those in the control group. The relative survival rates in the suspected patient group were significantly lower than those in the control group between 1981 and 1986. Recently the differences of the relative survival rates between the patient group and the suspected patient group have become smaller and are not significant. These results show the long-lasting influence of Itai-itai disease on the prognoses of patients and suspected patients.