Impact of including quantitative information in a decision aid for colorectal cancer screening: A randomized controlled trial

Abstract

Objective: Guidelines recommend that decision aids provide quantitative information about risks and benefits of available options. Impact of providing this information is unknown.

Methods: Randomized trial comparing two decision aids about colorectal cancer (CRC) screening with colonoscopy or fecal immunochemical test (FIT). 688 primary care patients due for CRC screening viewed a decision aid that uses words only (Verbal arm) vs. one that provides quantitative information (Quantitative arm). Main outcomes included perceived CRC risk, intent to be screened, and test preference, measured before and after viewing decision aid, and screening uptake at six months. Analyses were performed with ANCOVA and logistic regression.

Results: Compared to the Verbal arm, those in the Quantitative arm had a larger increase in intent to undergo FIT (p = 0.011) and were more likely to switch their preferred test from non-FIT to FIT (28% vs. 19%, p = .010). There were decreases in perceived risk in the Verbal Arm but not the Quantitative Arm (p = 0.004). There was no difference in screening uptake. Numeracy did not moderate any effects.

Conclusions: Quantitative information had relatively minor impact and no clearly negative effects, such as reducing uptake.

Practice implications: Quantitative information may be useful but not essential for patients viewing decision aids.