Effectiveness of physiotherapy modalities on persisting dyspnoea in long COVID: A systematic review and meta-analysis

Background: Dyspnoea is often found months and years later in the "long-covid" syndrome, impairing quality of life and further perpetuating anxiety and post-traumatic stress disorders. Physiotherapy was recommended as a treatment in long-covid, but there is still insufficient evidence on its effectiveness.

Methods: We conducted a systematic literature search on MEDLINE, PEDro, WOS, Scopus, VHL and the Cochrane Library until July 2023 (PROSPERO registration number: CRD42023427464). We selected comparative trials including adults with persistent breathlessness following COVID-19, regardless of the initial severity, for whom physiotherapy was implemented as a treatment for dyspnoea. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the PEDro Scale.

Results: 19 studies that included 1292 adults fulfilled the inclusion criteria, of which 15 were randomised controlled trials and 4 non-randomised controlled trials. As for the rehabilitation modalities, 6 studies used respiratory muscle training, 6 studies used low to moderate intensity rehabilitation, 6 used high intensity rehabilitation and one used passive rehabilitation. The methods used between and within each group differed greatly, leading to an expected high heterogeneity of results. Nethertheless the random-effects model found a significant difference favouring physiotherapy (SMD -0.63, 95 CI [-1.03; -0.24], p < 0.001, I² = 88 %). Subgroup analysis showed a significant effect in the high intensity rehabilitation group alone, with null heterogeneity.

Conclusion: In people suffering from dyspnoea following a SARS-CoV-2 infection, physiotherapy and especially pulmonary rehabilitation may help alleviate respiratory symptoms. Future studies will need to provide more consistent rehabilitation methods and better descriptions of them so as to reveal clear effects and avoid the confusion caused by using too many rehabilitation modalities.