Abstract
BACKGROUND: The COVID-19 pandemic disturbed sleep globally in both infected and uninfected individuals. Prolonged symptoms (particularly fatigue) after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (post-COVID 2019 syndrome (PCS)) remain a health issue. Whether there is a relationship between PCS and sleep disturbance is largely unknown, with most studies lacking uninfected controls. We assessed sleep behaviours in a large UK cohort, analysing sleep disruption, fatigue, SARS-CoV-2 infection and symptom duration. METHODS: UK adults previously recruited from the King's College London ZOE COVID Symptom Study to the COVID Symptom Study Biobank, with prospective symptom logging and SARS-CoV-2 testing, were invited to complete online validated questionnaires for sleep (Pittsburgh Sleep Quality Index, Sleep Condition Indicator, the STOP-Bang Questionnaire and Epworth Sleepiness Scale), fatigue (Chalder Fatigue Scale) and mental health (Generalised Anxiety Disorder 2 scale and Patient Health Questionnaire 2). Data were analysed considering SARS-CoV-2 infection, symptom duration and co-morbidities, including mental health. RESULTS: Questionnaires were completed by 3833 of 8355 participants (2089 infected, 1721 uninfected, 23 unknown). Individuals with longer (versus shorter) symptom duration had poorer sleep scores for multiple questionnaires, but SARS-CoV-2 infection had no independent effect on sleep. However, previously infected (versus uninfected) individuals had greater fatigue, over a year since infection. Longer symptom duration, poorer sleep scores and greater fatigue were also associated with higher contemporaneous levels of anxiety and depression; however, an independent effect of prior SARS-CoV-2 infection on fatigue remained after adjustment. Higher body mass index, greater age and prior co-morbidities also independently worsened sleep scores. CONCLUSIONS: Sleep disturbance contributes to prolonged symptom reporting, irrespective of SARS-CoV-2 infection. Proven sleep interventions may help individuals with post-pandemic fatigue, including PCS.