Background: Colonoscopic screening for colorectal cancer is being implemented in an increasing number of countries. This might lead to a demand for colonoscopies that could outstrip supply.
Objective: We wanted to investigate whether undergoing a colonoscopic examination for colorectal cancer would affect the utilization of later distal GI endoscopies for other indications than follow-up of the findings at the screening examination (usual-care endoscopies).
Design: Prospective case control study.
Patients: In 1996, a screening group of 634 individuals, aged 63 to 72 years, randomly drawn from the official population registry, was invited to a "once only" colonoscopic screening examination for colorectal cancer. A total of 451 individuals (71%) attended. An age- and sex-matched control group of 634 individuals was enrolled from the same registry. Both groups belonged to the encatchment area of a single hospital.
Main outcome measurements: Distal endoscopies performed in the 2 groups from January 1996 to November 2004 were registered by investigating medical records.
Results: A total of 1268 individuals (52.4% women) were followed for 9 years. Sixty-three individuals (9.9%) in the screening group and 110 (17.4%) individuals in the control group (odds ratio 0.53, 95% confidence interval 0.38-0.73) had had a total of 85 and 169 usual-care distal endoscopies, respectively (P < .001).
Conclusions: Undergoing a colonoscopic examination for colorectal cancer seems to reduce the utilization of later usual-care endoscopic examinations. This finding could have an impact on the estimation of endoscopic resources needed for colorectal cancer screening.