Effectiveness of a cancer risk prediction tool on lifestyle habits: a randomized controlled trial.

Background Risk prediction models offer a promising approach to lifestyle modification. We evaluated the effect of personalized advice based on cancer risk prediction in improving five lifestyle habits (smoking, alcohol consumption, salt intake, physical activity, and body mass index) compared to standard advice without risk prediction among a Japanese general population with at least one unhealthy lifestyle habit. Methods In a parallel-design, single-blind, randomized controlled trial between February 2018 and July 2019, 5984 participants aged 40-64 years with unhealthy lifestyle habits were recruited from persons covered under a life insurance policy. They were randomly assigned to an intervention or control group and received personalized or standard advice, respectively. They were also sent an invitation to participate in a lifestyle modification program aimed at improving lifestyle. Primary outcome was an improvement in lifestyle, defined as an increase in healthy lifestyle habits within 6 months. Results The proportion of participants who improved their lifestyle within 6 months in the intervention group did not significantly differ from that in the control group (18.4% vs 17.7%; p=0.488). Among participants with low health literacy and two or fewer of five healthy habits, the proportion of participants subscribing to the lifestyle modification program was higher in the intervention group than in the control group. Conclusions Compared to standardized advice, personalized advice based on cancer risk prediction had no effect on improving lifestyle. Impact Provision of predicted cancer risk information did not induce change in unhealthy lifestyle.