Relationship between risk information on total colonoscopy and patient preferences for colorectal cancer screening options: analysis using the analytic hierarchy process.

BACKGROUND

Although the fecal occult blood test (FOBT) is the preferred program for colorectal cancer screening in Japan, many medical institutions have recently begun to provide total colonoscopy (TCS) as an initial screening program. However, there are a number of severe risks associated with TCS, such as colorectal bleeding and perforation. The justification for performing such a procedure on healthy patients remains unclear. We used the analytic hierarchy process (AHP) to investigate whether risk information on TCS affects patient preferences for colorectal cancer screening.

METHODS

We performed a questionnaire survey using an AHP decision-making model, targeting 285 people aged 40-59 years. We randomly assigned the subjects into Groups A (n = 146) and B (n = 139). Both groups were provided with information on the effectiveness, cost and disadvantages of the two screening programs. Group A was provided with additional information regarding the risks of TCS. Individual priorities were calculated with pair-wise comparisons between the two alternatives in each selection criteria. The influence of the risk information was analyzed using a logistic regression analysis.

RESULTS

The aggregated priorities in Group A for 'effectiveness', 'costs', and 'risks' were 0.603, 0.147, and 0.250, respectively, while those in Group B were 0.652, 0.149, and 0.199, respectively. A logistic regression analysis showed that the provision of risk information significantly reduced the subjects' priorities for TCS (p = 0.036).

CONCLUSION

The lack of risk information was related to the differences in priorities assigned to effectiveness and risks of the two procedures. Patients must be well informed before making decisions concerning their preferred colorectal cancer screening procedure.