Colorectal carcinoma. A staff model HMO's experience with screening and hospital use. ANCHOR Organization for Health Maintenance, Chicago, Illinois.

The authors present a staff model HMO's experience over an 18 month prospective period with the 35 cm flexible sigmoidoscopy (FS) and over a three year retrospective period of colorectal carcinoma related hospitalizations. In 735 asymptomatic patients receiving FS, 54 (7.3%) polyps and 5 (.68%) carcinomas (4 Dukes'A and 1 Dukes'B) were detected by FS. In asymptomatic patients who were fecal occult blood test (FOBT) positive, 3 (3.3%) carcinomas and 8 (8.9%) polyps were detected by FS. Additionally, one FOBT negative, FS negative patient had a Dukes' A carcinoma detected by screening air contrast barium enema. In a 3-year period, 35 carcinomas were diagnosed (18 symptomatic, 17 asymptomatic). Relative to asymptomatic patients, symptomatic patients averaged lower estimated 5-year survival rates (59% vs. 84%), longer initial hospitalizations (13.7 vs. 8.3 days), and significantly more advanced (non-Dukes'A) carcinomas (89% vs. 41%) (p less than .01), respectively. There were 7 deaths in 42 patients hospitalized during this study period. Estimated cost of screening and diagnostic evaluation in these 735 FS patients was $75,827 or $12,638/carcinoma detected. Two screening models are outlined with costs and benefits estimated for each model. From past experience and a review of the literature, the authors currently use seven guidelines for the early detection and prevention of colorectal carcinoma.