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

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][1] Identifier: [NCT04974775][2], registered April 28, 2020. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement AF and HF were supported by governmental funding of clinical research within the Swedish National Health Service (ALF), regional funding from Region Sk ̊ane, the Swedish Heart-Lung Foundation and Sk ̊ane University Hospital Funds ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Swedish Ethical Review Authority approved the SweCrit COVID-19 study (Dnr: 2020-01955, 2020-03483, 2021-00655) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The datasets used and analysed during the current study are available from the corresponding author upon reasonable request * ARDS : Acute respiratory distress syndrome BMI : Body mass index BP : Bodily pain CI : Confidence interval COVID-19 : Coronavirus disease 2019 CRRT : Continuous renal replacement therapy ECMO : Extracorporeal membrane oxygenation GH : General Health GOSE : Glasgow outcome scale-extended HRQoL : Health-related quality of life ICU : Intensive care unit IMV : Invasive mechanical ventilation LOS hospital : Hospital length of stay LOS ICU : ICU length of stay MID : Minimally important difference MH : Mental health MCS : Mental component summary OECD : Organisation for Economic Co-operation and Development OR : Odds ratio PaCO2 : Arterial partial pressure of carbon dioxide PaO2 : Arterial partial pressure of oxygen PaO2/FiO2 (P/F) : Arterial oxygen partial pressure ratio to fractional inspired oxygen PCS : Physical component summary PF : Physical functioning PICS : Post-intensive care syndrome RT-PCR : Real-time reverse transcriptase-polymerase chain reaction RE : Role emotional SAPS 3 : Simplified acute physiology score 3 SARS-CoV-2 : Severe acute respiratory syndrome Coronavirus 2 SF-36v2® : Short form health survey version 2 SIR : Swedish intensive care registry SF : Social functioning SOFA : Sequential organ failure assessment SPSS : Statistical Package for the Social Sciences STROBE : Strengthening the Reporting of Observational Studies in Epidemiology VAS : Visual analogue scale VT : Vitality WHO : World Health Organization [1]: http://ClinicalTrials.gov [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT04974775&atom=%2Fmedrxiv%2Fearly%2F2024%2F05%2F02%2F2024.05.01.24306267.atom