The Relationship Between Breast Cancer Risk and Sleep Quality Among Night Shift Nurses: Descriptive Cross-Sectional Study

Objective: The aim of this study was to investigate the relationship between breast cancer (BC) risk level and sleep quality among nurses working night shifts. Material and Methods: This descriptive, cross-sectional study was conducted from January 30 to July 30, 2018, in two hospitals in the Sivas Province. Data were collected using a questionnaire, the Ministry of Health Breast Cancer Risk Assessment Form, and the Pittsburgh Sleep Quality Index. In the data analysis, descriptive statistics, non-parametric tests, and the Spearman correlation coefficient were used. Results: A total of 110 nurses participated in the study. Those with 11 or more years of night-shift experience had higher mean BC risk scores and lower sleep quality scores. However, these differences were not statistically significant (p>0.05). Correlation analysis revealed that working one to three night shifts per week was associated with an increased risk of BC, while working three or more night shifts per week was linked to poorer sleep quality. Significant correlations were found between BC risk and age, body mass index, family history of BC, having children, breastfeeding, total work years, and years of night-shift work (p<0.001). No significant relationship was observed between sleep quality and BC risk (p>0.05). Conclusion: These findings suggest that night-shift work is linked to an increased risk of BC and poor sleep quality among nurses. While sleep quality was not significantly associated with BC risk, total years of work and cumulative years of night-shift work were significantly related to a higher BC risk.