Effectiveness of respiratory rehabilitation for pulmonary function and exercise capacity in patients with or post-covid-19: a systematic review and meta-analysis

Coronavirus disease 2019 (COVID-19) may impair exercise capacity and pulmonary function. This systematic review evaluated the effectiveness of respiratory rehabilitation for these outcomes, with meta-analyses conducted where appropriate. PubMed, Embase, Web of Science, Scopus, the Cochrane Library, China National Knowledge Infrastructure, SinoMed, Wanfang Database, and the Chinese Science and Technology Journal Database were searched from inception to 29 November 2024. Grey literature, trial registries, and reference lists were also searched. No language restrictions were applied. Studies evaluating respiratory rehabilitation in patients with COVID-19 or post-COVID conditions were eligible. Controlled studies were included in quantitative syntheses, whereas uncontrolled single-group pre-post studies were narratively summarized. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Cochrane Risk of Bias 2 (RoB 2) tool for randomized trials, the Newcastle-Ottawa Scale for non-randomized comparative studies, and the Joanna Briggs Institute critical appraisal checklist for uncontrolled studies. Certainty of evidence was assessed using the GRADE approach. Of 708 records identified, 11 studies involving 507 participants were included. Eight controlled studies contributed to the meta-analyses, and three uncontrolled studies were narratively synthesized. Respiratory rehabilitation was associated with a significant improvement in six-minute walk distance (6MWD; mean difference [MD] = 47.70 m, 95% confidence interval [CI]: 25.36 to 70.04; P < 0.001) and FEV1% predicted (MD = 5.05 percentage points, 95% CI: 2.30 to 7.81; P < 0.001). No statistically significant association was observed for the FEV1/FVC ratio (MD = 1.61 percentage points, 95% CI: −1.25 to 4.47; P = 0.27). One trial was at high risk of bias because of missing outcome data, while the remaining studies raised some concerns. Respiratory rehabilitation may improve functional exercise capacity and FEV1% predicted in patients with COVID-19 or post-COVID conditions. However, its effect on the FEV1/FVC ratio remains uncertain. These findings should be interpreted cautiously in view of clinical heterogeneity, risk of bias, and limited certainty of evidence. Not applicable.