Functional Recovery of Adults Following Acute COVID-19: A Systematic Review and Meta-Analysis.

Objective: This systematic review and meta-analysis aimed to investigate the objective, functional recovery of patients more than 3 months after acute COVID-19 infection.

Methods: Comprehensive database searches of EMBASE, PubMed/MEDLINE, Cochrane COVID-19 Study Register, CINAHL, and Google Scholar in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement were carried out until October 19, 2022. Data were extracted and agreed in duplicate. Data were narratively synthesized, and a series of meta-analyses were performed using the random-effects inverse variance method.

Results: One-hundred six papers covering 20,063 patients who were either hospitalized or not hospitalized with acute COVID-19 who were followed-up between 3 to 24 months were included. Percentage predicted 6-minute walk distance at 3 months to <5 months was 84.3% (95% CI = 79.2-89.3; n = 21; I2 = 98.3%) and 92.5% (95% CI = 89.8-95.3; n = 9; I2 = 94.5%) at ≥11 months. Cardiopulmonary exercise testing revealed percentage predicted peak oxygen consumption rate ($peak\dot{\mathrm{V}}{\mathrm{o}}_2$) at 3 months to <5 months was 77.3% (95% CI = 71.0-83.7; n = 6; I2 = 92.3%) and 95.4% (95% CI = 87.1-103.6; n = 2; I2 = 77.3%) at ≥11 months. Mean handgrip strength was greatest at ≥11 months at 31.16 kg (95% CI = 19.89-42.43; n = 2; I2 = 98.3%) of all time points. All analyses showed marked heterogeneity.

Conclusion: Patients have reduced physical function more than 3 months after COVID-19 infection. Better physical function in multiple physical domains is found after a longer recovery time.

Impact: Physical function as measured by the 6-minute walk test, hand grip strength, and cardiopulmonary exercise testing is reduced at 3 months after COVID-19 infection and can remain over 11 months of follow-up. This protracted recovery following acute COVID-19 infection supports the need to assess physical function at any clinical follow-up, and further research into rehabilitation programs and intervention for patients who have not recovered.