Lifestyle in population-based colorectal cancer screening over 2-year follow-up

Background: Colorectal cancer (CRC) screening may cause changes in health-related lifestyle. In 2010, Finnish Mass Screening Registry began a study on psychosocial effects of CRC screening. This article examines whether there are differential developments in self-reported lifestyle at ages 59-61 years among CRC screening invitees and non-contacted controls. Methods: A population-based random sample of 10 648 Finnish adults born in 1951 and living in the municipalities voluntary involved in the CRC screening programme were sent a lifestyle questionnaire in 2010. In 2011, the cohort was randomised (1 : 1) for their first ever CRC screening at age 60 or for controls. The questionnaires were repeated in 2012 for all. From both survey rounds, 2508 pairs of completed questionnaires were available for analysis from the screening group and 2387 from the control group. The outcome was 2-year change in total lifestyle index of CRC risk factors (diet, physical activity, body mass index, alcohol consumption and smoking). Results: Total lifestyle index decreased throughout the follow-up in both the screening group [odds ratio (OR) = 0.80, 95% confidence interval (CI) 0.72-0.90] and in the control group (OR = 0.80, CI 0.71-0.90) indicating no difference in lifestyle changes between groups. There was also no significant difference by screening participation: the change in score was similar in those participating screening (OR 0.81, CI 0.72-0.92) and in those invited, but not participating (OR 0.75, CI 0.55-1.03). Conclusion: Present study found no unfavourable changes in total lifestyle in the studied age group due to CRC screening. Results are reassuring from the point of view of CRC screening evaluation.