Factors influencing long-term recovery in critically ill COVID-19 survivors: A prospective multicentre cohort study

Abstract Background Long-term outcomes after critical COVID-19 have not been sufficiently studied. This study aimed to describe changes in functional outcome and health-related quality of life (HRQoL) assessed at 3 and 12 months in a cohort of critically ill COVID-19 survivors. A secondary aim was to investigate factors associated with good functional outcome and HRQoL at 12 months. Methods This prospective multicentre cohort study included critically ill COVID-19 patients admitted to six intensive care units in Sweden between May 2020 and May 2021. Surviving patients were invited to face-to-face follow-ups at 3 and 12 months. A good functional outcome was a Glasgow outcome scale extended ≥7. HRQoL was assessed by the physical and mental component summary of the SF-36v2®, with T-scores ≥45 representing a good HRQoL. Factors associated with good functional outcome and HRQoL at 12 months were explored by multivariable logistic regression. Results A good functional outcome was found in 93/264 (35%) and 138/217 (64%) of survivors at 3 and 12 months, respectively. There was a significant improvement in the SF-36v2® Physical component summary (PCS) between 3 and 12 months (mean 40 versus 44, p < 0.001). The SF-36v2® Mental component summary (MCS) was within the normal range at 3 months, with no significant change at 12 months (mean 46 versus 48, p=0.05). Older age was associated with a good functional outcome. Low clinical frailty and absence of diabetes mellitus were associated with a good physical HRQoL. A shorter duration of mechanical ventilation was associated with a good outcome for all three outcome measures. Conclusion Between 3 and 12 months, functional outcome and physical aspects of HRQoL significantly improved, indicating continued recovery up to at least one year after critical COVID-19. Low frailty, less comorbidity, and shorter duration of mechanical ventilation were associated with better long-term outcomes, while old age was associated with better functional outcome. Study registration ClinicalTrials.gov Identifier: NCT04974775 , registered April 28, 2020.