Psychometric properties of the Survey of Shiftworkers (SOS) in a sample of Iranian nurses

Due to the rapid growth of technology, shiftwork has become an integral part of most workplace activities. The purpose of this study was to examine the psychometric properties of the Persian translation of the Survey of Shiftworkers (SOS). In this descriptive cross-sectional study, the population consisted of all nurses employed by three teaching hospitals in Bojnord, Iran in 2017 (n = 455), of which 236 were selected using stratified sampling. The study participants were assessed using the SOS developed by Barton et al., in 1995. To evaluate the validity of the questionnaire, Pearson's correlation coefficient, exploratory factor analysis of the main components, and confirmatory factor analysis were employed; Cronbach's alpha coefficient was used to evaluate the reliability of the questionnaire. The participants' mean score on the SOS was 193 ± 30.52, with total scores ranging from 103 to 285. The internal reliability of the questionnaire was 0.83 using Cronbach's alpha coefficient. Varimax orthogonal rotation was used to analyze the main components of the tool and the results indicated 8 components (cardiovascular symptoms, digestive symptoms, musculoskeletal pain, general health, chronic fatigue, social and domestic disturbances, sleep disturbances, and neuroticism), which explained 56.66% of the variance in the scores. Additionally, the confirmatory factor analysis supported the 8-factor model. Validation of the SOS confirmed the convergent validity of its subscales. The Persian version of the SOS is freely available and can be used as a suitable tool in industrial, non-industrial, and research environments to evaluate shiftwork-associated problems in other Persian-speaking populations.