Interhospital Differences in Cancer Survival: Magnitude and Trend in 1975–1987 in Osaka, Japan

This study addresses the disparity in cancer survival rates among hospitals in Osaka, Japan, Using data from the Osaka Cancer Registry, four‐year survival rates for stomach cancer patients (n=8,845) diagnosed in 1976, 1981 and 1986, and lung cancer (n = 9,795) and breast cancer patients (n= 7,377) diagnosed in 1975–77, 1980–82 and 1985–87 were calculated according to four hospital categories (teaching hospitals, large hospitals: 400+ beds excluding teaching hospitals, medium‐size hospitals: 150–399 beds, and small hospitals: 20–149 beds). Cox's proportional hazards model was employed with adjustment for sex, age, clinical stage at diagnosis, and treatment status. Stomach and lung cancer patients treated in large, medium‐size and small hospitals showed significantly higher risks of death than those treated in teaching hospitals in 1975–87. Interhospital differences in breast cancer survival appeared to increase in 1975–87, whereas those in stomach and lung cancer survivals decreased during the same period.