Factors Influencing Cumulative Fatigue Symptoms in Female Nurses Working in Two Shifts Rotation System in Japan

Background: This study aimed to clarify factors affecting cumulative fatigue in nurses working two-shift rotations system with 16-hour night time shifts. Methods: A cross sectional design was employed; subjects were 96 nurses. The Cumulative Fatigue Symptoms Index (CFSI) was used to assess cumulative fatigue, and number of steps was counted as an objective measure/ index of physical activity. Data were collected over four days, which included a day shift, night shift, and day off a series of nursing shift. Participant characteristics such as their CFSI scores and years of experience were analyzed using a Mann-Whitney U or a Kruskal–Wallis test. In addition, logistic regression analysis was performed to examine the association between cumulative fatigue and potential contributing factors. Results: Valid data were obtained from 96 female nurses. Cumulative fatigue was found to be related to having less than 5 years of clinical experience (OR = .22, 95% CI=.05-.92), subjective busyness of nightime shifts (OR = 3.12-3.69, 95% CI= 1.06-12.11), and the number of steps taken on one’s day off (OR =.03, 95% CI= .10-.92). The subjective busyness in night shift work was an increasing risk factor of CFSI, and less than 5 years clinical experience and the numbers of steps of day off were lowering risk factors of CFSI. Conclusion: Clinical experience less than 5 years, subjective busyness in night shift work, and the number of steps on a day off as a measure of physical activity were identified as factors associated with CFSI in nurses working in two-shift rotation system.