Person-years For Males Research Articles

Gastric cancer screening was conducted on a cohort of 1,553 subjects aged 40 and over as of 1961 in Hisayama, Japan for 12 years from 1964 to 1975. One thousand one hundred and fifteen out of 1,553 subjects or 71.8% of the cohort were examined at least once. Sixty cases of gastric cancer were detected in the cohort; 24 cases (40.0%) by screening, 20 (33.3%) by clinics and 16 (26.7%) by autopsy. The incidence rate of gastric cancer of the cohort was calculated at 540.5 per 100,000 person years for males and 243.5 for females, respectively. The death rate of gastric cancer in the screened population was lower than that in the unscreened population, but the difference was not statistically significant. To further evaluate the screening program, persons dying from gastric cancer were compared for participation or non participation in the screening program. The risk of death from gastric cancer in the screened cases was compared with that in the unscreened cases using the Mantel Haenszel method for adjusting sex, age and the date of detection. It was found that the risk of death from gastric cancer among the screened cases was significantly lower than that in the unscreened cases (P=0.009). The risk ratio was calculated at 0.031. The results suggest that the gastric cancer screening program was effective in the community. Target population in terms of age for the screening was discussed in the paper.

Read full abstract