The CRISP Trial: RCT of a decision support tool for risk-stratified colorectal cancer screening

Background: A risk-stratified approach to colorectal cancer (CRC) screening could result in more acceptable balance of benefits and harms and be more cost-effective. Aim: To determine the effect of a consultation in general practice using a computerised risk assessment and decision support tool (CRISP) on risk-appropriate CRC screening. Design and setting: RCT in 10 general practices in Melbourne, Australia. Methods: Intervention consultations included CRC risk assessment using the CRISP tool, and discussion of CRC screening recommendations. Control group consultations focused on lifestyle CRC risk factors. Participants were recruited from a consecutive sample of patients aged 50-74 attending their general practitioner. Primary outcome: Risk-appropriate CRC screening at 12-months. Results: 734 participants (65.1% of eligible patients) were randomised (369 intervention, 365 control); the primary outcome was determined for 722 (362 intervention, 360 control). There was a 6.5% absolute increase (95% CI: -0.28 to 13.2%) in risk-appropriate screening in the intervention compared to control group [71.6% vs 65%; OR: 1.36 (95% CI: 0.99 to 1.86) p = 0.057]. In those due CRC screening during follow-up, there was a 20.3% (95% CI:10.3 to 30.4%) increase [intervention 59.8% vs control 38.9%; OR: 2.31 (95% CI 1.51 to 3.53) p < 0.001] principally by increasing faecal occult blood testing in those at average risk. Conclusions: A risk assessment and decision support tool increases risk-appropriate CRC screening in those due screening. The CRISP intervention could commence in people in their fifth decade to ensure people start CRC screening at the optimal age with the most cost-effective test.