Background
A risk-stratified approach to colorectal cancer (CRC) screening could result in a more acceptable balance of benefits and harms, and may be more cost-effective. The CRISP Trial tested the effect of a consultation in Australian general practice using a computerised risk assessment and decision support tool on the incidence of risk-appropriate CRC screening.
Methods
Eligible participants were aged 50-74 attending their general practitioner (GP). Intervention consultations included assessment of CRC risk using the CRISP risk assessment and decision support tool, discussion of risk-appropriate CRC screening recommendations, and a report to the participant and their GP. Control group consultations focused on modifiable lifestyle risk factors and a brochure on cancer prevention. Parallel, individual randomisation, 1:1 stratified by practice, occurred via an on-line platform. Participants and researchers conducting data extraction and statistical analyses were blinded to group allocation. The primary outcome was risk-appropriate CRC screening at 12-months.
Results
We randomised 734 participants (369 intervention, 365 control; accrual target met); the primary outcome was determined for 722 (362 intervention, 360 control). There was a 6.5% increase (95% CI: -0.28 to 13.2%) in risk-appropriate screening in the intervention arm compared to control arm [71.6% vs 65%; OR: 1.36 (95% CI: 0.99 to 1.86) p = 0.06]. The effect was greater in those due CRC screening during the follow-up period [59.8% vs 38.9%; difference 20.3% (95% CI:10.3 to 30.4%); OR: 2.31 (95% CI 1.51 to 3.53) p < 0.001] and occurred principally by increasing faecal occult blood testing in those at average risk.
Conclusion
A consultation in general practice using a risk assessment and decision support tool can increase risk-appropriate CRC 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.