Rotating shift work and colorectal cancer among nurses and midwives: a cross-sectional study

Objective The main aim of this study was to explore any association between colorectal cancer (CRC) and rotating shift work in nurses and midwives. The secondary aim of this study was to identify risk factors for CRC in nurses and midwives who are rotating shift workers. Design Cross-sectional study. Setting Electronic survey of participants from Australia, New Zealand and the United Kingdom. Subjects A sample of 8,199 male and female nurses and midwives from Australia, New Zealand and the United Kingdom invited through their registration papers or newsletter advertisement. Main outcome measure Prevalence of CRC in participants who have worked rotating shifts for 1-14 years or >= 15 years compared to participants who have never worked rotating shifts. In addition, risk factors for CRC in the rotating shift work population were analysed in a multivariate logistic regression model in order to obtain odds ratio of CRC. Results No statistically significant difference was found in the prevalence of CRC between those who have never worked rotating shift work, worked 1-14 years and worked 15 or more years. Among rotating shift workers, diabetes was associated with a 123-fold (95% CI 39-392; p<0.001) increased odds of CRC, while Inflammatory Bowel Disease (IBD) was associated with a 190-fold (95% CI 68-526; p<0.001) increased odds of CRC. Screening colonoscopy or sigmoidoscopy for CRC was associated with a 10-fold (95% CI 3-35; p<0.001) increased odds of being diagnosed with CRC. Conclusion No significant association was found between rotating shift work and colorectal cancer in nurses and midwives. In nurses and midwives who are rotating shift workers, diabetes, IBD and CRC screening significantly increased the odds of CRC.