Psychometric properties of the Korean version of the Occupational Fatigue Exhaustion Recovery Scale in a nurse population

Most nurses in Korea work rotating shifts, an important contributor to fatigue. The Occupational Fatigue Exhaustion Recovery (OFER) Scale assesses work-related fatigue among nurses. In this study, we aimed to translate and culturally adapt the Korean version of this scale (OFER-K) with nurses working rotating shifts in Korea. Instrument adaptation was performed using committee-based translation, cognitive interviewing, and expert panel interviewing. Criterion validity, convergent validity, construct validity, internal consistency, and test-retest reliability were examined as psychometric properties of the OFER-K. An online survey was completed by 331 nurses; 107 of these nurses completed a second survey after 1 month to assess test-retest reliability. The overall Cronbach's alpha was 0.88. The correlation between participants' initial and retest responses for the total scale was 0.64 (p < .001). The chronic fatigue subscale was stable over time, t(106) = -1.76, p = .08. Criterion and convergent validity were supported by correlations between the OFER-K scale and the Chalder Fatigue Questionnaire, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index. Confirmatory factor analysis showed a good fit using a three-factor model. The findings of this study showed that the OFER-K scale is a reliable and valid instrument for assessing chronic fatigue, acute fatigue, and inter-shift recovery in Korean nurses. Future research using this scale may lead to a better understanding of the antecedents and consequences of nurse fatigue and could provide important information to nurse researchers, administrators, and policymakers for developing interventions to reduce nurse fatigue.