Interhospital differences in cancer survivals in Japan. The Research Group for Population-based Cancer Registration in Japan.

The present study was an investigation of variations in cancer survival rates among hospitals in Japan, focusing in particular on the number of hospital beds as an institutional characteristic. Using data from 11 population-based cancer registries, the three-year survival rates for stomach cancer (n 1665), colorectal cancer (n 1090) and lung cancer (n 895) patients diagnosed in 1985 were calculated according to three different hospital categories (100-299, 300-499, 500+ beds). Cox's proportional hazards model was conducted, with adjustments for sex, age, clinical stage at diagnosis and treatment status, excluding patients who had been detected by screening (asymptomatic cases). The stomach and lung cancer patients treated in small hospitals (100-299 beds) were at a significantly higher risk of death than those treated in large hospitals (500+ beds) (hazard ratio (HR) = 1.36, 95% confidence interval (CI) = 1.11-1.65; HR = 1.41, 95% CI = 1.13-1.77, respectively). Similar findings were observed among colorectal cancer patients although they were not statistically significant. The findings can provide some information useful for the development of future public health policies aimed at controlling cancer mortality rates in our country.