Background/aims: To evaluate the optimal sampling times of stool in immunochemical occult blood screening from the viewpoint of the cost-effectiveness.
Methodology: A colorectal cancer screening was conducted in 5 municipalities (Matsumoto, Hata, Yamagata, Asahi, Sakai), Nagano prefecture, Japan in 1996. Each participant received a fecal occult blood test with 3 consecutive days. For the economic assessment of testing methods, the results of the 1st day, those of the 1st and 2nd days and those of the 3 consecutive days were used for a single-day method, a 2-day method, and a 3-day method. The average costs per detection of one cancer patient and diagnostic validity were evaluated among 3 months.
Results: The average costs for one cancer case detected were calculated to be $5924 for a single-day method, $6014 for a 2-day method, and $7123 for a 3-day method, respectively. The sensitivity and specificity were calculated to be 58% and 96% for a single-day method, 89% and 95% for a 2-day method, and 100% and 94% for a 3-day method, respectively, indicating a significant difference in the sensitivity between a single-day method and a 2-day as well as a 3-day method (P < 0.05), and in the specificity among 3 testing methods (P < 0.001).
Conclusions: The present analysis suggests that a 2-day collection method is recommended in the immunochemical occult blood screening from the viewpoint of the cost-effectiveness as well as the diagnostic accuracy.