Sleep behavior of shift workers who maintained external work activities during the period of social restriction of COVID-19

ABSTRACT

Introduction: Sleep contributes to the proper functioning of the body and the immune system. During the COVID-19 pandemic, isolation was a strategy to contain the spread of the virus and altered daily routine and sleep. Some studies have shown improved sleep in some populations, while others have reported worsening, especially in health shift worker groups. Objective: To compare the sleep behavior of shift workers at a mining company, who remained active before and during the isolation period of the COVID-19 pandemic. Methods: The sample consisted of 15 workers (14 men and 1 woman) of a mining company in the State of Minas Gerais, aged 38.9 ± 3.5 years. All worked 6 hours a day in a fast-rotating shift (4x1) for 10.2±3.8 years on average. To assess sleep behavior, the actigraphy method was used, which assesses sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TTS) all in minutes and sleep efficiency (ES) in percentage values. The assessments were carried out in October and November 2019 for the pre-pandemic moment and November and December 2020 for the postpandemic moment. For comparison between moments, the paired t-test was used, considering the value of p ≤ 0.05. Results: Clinically, sleep behavior in this group of shift workers did not change. Only SOL (3.4±1.7 vs. 1.9±0.9) showed a statistical difference (t(14)=4.399, p=0.001), while WASO (t(14)=0.916;p=0.375) with means 18.1±8.5 vs. 16.9±6.4, TTS (t(14)=-1.258;p=0.229) 422.5±36.9 vs. 437.2±68.9 and ES (t(14)=-0.934, p=0.366) 92.8±2.8 vs. 93.3±2.9 before and after the pandemic, respectively, showed no difference. Conclusion: The maintenance of external work, in the mining company, even with social restrictions in the workplace and outside it, contributed to the maintenance of the routine and sleep behavior. However, the workers in this study did not face increased workload, anxiety and greater risk of contagion associated with the work environment as health workers. Our results indicate that the improvement or worsening of sleep before and after the pandemic should be related to the group and culture that will be evaluated. The authors thank the support given by Pró-Reitoria De Pesquisa (PRPq) and PPG em Ciências do Esporte UFMG, Instituto Tecnológico VALE (ITV), CEPE (Centro De Estudos em Psicobiologia e Exerćcio), CEMSA (Centro Multidisciplinar De Sonolência e Acidentes), CNPq, FAPEMIG, CAPES e FEPE-UFMG.