Abstract
Background: Insomnia significantly impairs healthcare worker (HCW) well-being, particularly amid COVID-19 sequelae and shift work demands. We aimed to assess the prevalence of insomnia among HCWs, identify those needing clinical intervention, analyze shift work as a potential risk factor, and explore associations with COVID-19 sequelae and psychiatric comorbidities. Methods: A cross-sectional online survey was administered at the University of Salamanca University Care Complex (CAUSA) from March 2023 to January 2024. Validated scales (Insomnia Severity Index, Patient Health Questionnaire-4, Generalized Anxiety Disorder Scale-2) were used to measure insomnia, depression, and anxiety. Participants scoring ISI ≥ 7 were invited for Occupational Medicine follow-up. Descriptive and inferential analyses were performed. Results: Overall, 1121 HCWs participated (mean age 44.59 ± 11.78, 78.3% women). The mean ISI score was 10.5 ± 5.8 (subclinical insomnia), with 22.7% reporting moderate and 3% reporting severe insomnia. Depression and anxiety affected 28.4% and 33% of respondents, respectively. Shift workers had poorer sleep (mean ISI 11.3 ± 0.9 vs. 8.8 ± 0.3, p < 0.001). Individuals reporting COVID-19 sequelae were 3.1 times more likely to have insomnia than those who did not (mean ISI 13.89 ± 5.9 vs. 10.33 ± 5.7, p < 0.001). Over one-quarter reported at least the monthly use of sleep or psychiatric medications. Conclusions: Insomnia remains prevalent among HCWs, influenced by shift work, COVID-19 sequelae, and mental health factors. Targeted, multidisciplinary interventions, e.g., workplace policy changes, mental health programs, and shift schedule adjustments) are urgently needed to safeguard well-being, reduce burnout, and maintain quality patient care. Ensuring adequate sleep is central to minimizing errors and preserving professional performance. Future studies should investigate the impact of coordinated workplace strategies to effectively address insomnia.