Factors influencing fatigue and its correlation with depressive symptoms, and their impact on turnover or transfer intentions: a retrospective study in an Okinawan ICU

Abstract

Objective: This study aimed to investigate factors influencing fatigue, its relationship with turnover or transfer intention (TTI), and its impact on the mental health of intensive care unit (ICU) nurses in rural Okinawa, Japan. In this region, career options are limited, and many female nurses struggle with balancing work and household responsibilities, potentially contributing to fatigue and mental health challenges.

Patients and methods: A retrospective observational study was conducted with 28 ICU nurses from an acute care hospital in Okinawa. Fatigue and depressive symptoms were assessed using the Japanese Workers' Accumulated Fatigue Self-Diagnosis Checklist and Patient Health Questionnaire-9 (PHQ-9). Participants were categorized according to fatigue levels (Low-High and Highest) and TTI status. Univariate analysis was used to examine the relationships between fatigue, TTI, and variables including gender, marital status, interpersonal issues, and nursing experience.

Results: The Highest fatigue group accounted for 67.9% of the participants, and 42.9% were classified as having mild depression. The Highest fatigue group showed significantly higher PHQ-9 scores, longer nursing experience, and higher proportions of married nurses compared to the Low-High fatigue group (P<0.05). Fatigue and PHQ-9 scores were positively correlated (r=0.657, P<0.001). TTI was reported by 46.4% of participants, with significantly higher rates observed among female nurses experiencing interpersonal issues and those in the Highest fatigue group (P<0.05).

Conclusion: This study found a correlation between ICU nurses' subjective fatigue and mental health, suggesting that severe fatigue, particularly due to interpersonal challenges, may be linked to TTI, highlighting the need for early interventions. However, no direct link was found between fatigue, depressive symptoms, and TTI. Further longitudinal research is required to clarify causality and enhance interventions. In rural areas such as Okinawa, where career options are limited, tailored interventions targeting fatigue and interpersonal challenges are essential.

Keywords: depressive symptoms; intensive care unit (ICU) nurses; subjective fatigue; turnover; work environment.

Figure 1

The study flow and eligibility criteria.

Figure 2

The correlation between fatigue accumulation and PHQ-9. Spearman’s rank correlation coefficient was used for statistical analysis. A total of seven data points overlapped across three locations: two for (6,5), three for (6,2), and two for (4,1) in terms of fatigue accumulation and PHQ-9 scores. Consequently, the figure appears to show 21 data points instead of the actual 25, which is four times fewer than the true count. PHQ-9: Patient Health Questionnaire-9.