The association of Shift Work and Effort–Reward Imbalance with Gastrointestinal Symptoms among Female Nurses

Background: Shift work impacts workers' health, mainly by disrupting the circadian rhythm, and gastrointestinal (GI) disturbances are among the health effects of shift work. Objectives: The objective of this study was to assess the association between shift work, work stress, and GI disturbance among nurses. Methods: In July 2018, a cross-sectional study was conducted in Dammam Medical Complex, Saudi Arabia. A total of 250 nurses were selected through convenience sampling from several departments. They completed a validated questionnaire, which included questions about their demographic data, GI symptoms, and effort–reward imbalance (ERI). Work stress was classified into two groups based on the ERI ratio. GI symptoms were categorized into three indices: total, upper, and lower GI. The sampling plan was designed to cover most of the shifts in the included departments throughout nonspecified dates. The daytime nurses' group was selected from the same hospital as a comparison group to the shift workers. Means and standard deviations were calculated for continuous variables and frequencies and percentages were calculated for categorical variables. The associations were assessed using the Chi-squares and analysis of variance. Results: Work stress among nurses, as measured by the ERI scale, was strongly associated with both upper and lower GI symptoms, with odds ratios of 5.7 (CI: 3.3–7.9) and 2.2 (CI: 1.8–4.3), respectively. The total GI symptom score of the shift workers was greater than that for the daytime workers, with means of 7.8 ± 6.9 and 5.4 ± 5.1, respectively (P = 0.005). Multivariable regression analysis showed that ERI was associated with both lower and upper GI symptoms after adjusting for shift work and years on the job. Conclusions: Shift work was associated with the high prevalence of GI symptoms. Stress (ERI) increased the risk for GI disturbance. Controlling work stress is necessary because it affects nurses' physical and social health, as well as their performances at work and the quality of care they provide.