Association of socioeconomic status with sleep disturbances in the Swiss population-based CoLaus study.

OBJECTIVE: To examine the association of socioeconomic status (SES) with subjective and objective sleep disturbances and the role of socio-demographic, behavioural and psychological factors in explaining this association. METHODS: Analyses are based on 3391 participants (53% female, aged 40-81 years) of the follow-up of the CoLaus study (2009-2012), a population-based sample of the city of Lausanne, Switzerland. All participants completed a sleep questionnaire and a sub-sample (N = 1569) underwent polysomnography. RESULTS: Compared with men with a high SES, men with a low SES were more likely to suffer from poor sleep quality [prevalence ratio (PR) for occupational position = 1.68, 95% Confidence Interval (CI): 1.30-2.17], and to have long sleep latency (PR = 4.90, 95%CI: 2.14-11.17), insomnia (PR = 1.47, 95% CI: 1.12-1.93) and short sleep duration (PR = 3.03, 95% CI: 1.78-5.18). The same pattern was observed among women (PR = 1.29 for sleep quality, 2.34 for sleep latency, 2.01 for daytime sleepiness, 3.16 for sleep duration, 95%CIs ranging from 1.00 to 7.51). Use of sleep medications was not patterned by SES. SES differences in sleep disturbances were only marginally attenuated by adjustment for other socio-demographic, behavioural and psychological factors. Results from polysomnography confirmed poorer sleep patterns among participants with low SES (p <0.05 for sleep efficiency/stage shifts), but no SES differences were found for sleep duration. CONCLUSIONS: In this population-based sample, low SES was strongly associated with sleep disturbances, independently of socio-demographic, behavioural, and psychological factors. Further research should establish the extent to which social differences in sleep contribute to socioeconomic differences in health outcomes.