Effects of incentive spirometer added to standard rehabilitation in previously hospitalized adults with post-COVID-19 condition: a randomized controlled trial

OBJECTIVE: Post-COVID-19 condition is associated with persistent respiratory symptoms and impaired functional capacity. This study evaluated the effects of adding an incentive spirometer to standard rehabilitation in adults with post-COVID-19 condition, with peak expiratory flow, dyspnoea, and quality of life as the prespecified primary outcomes. DESIGN: Randomized controlled trial. SUBJECTS/PATIENTS: Eighty-two previously hospitalized adults diagnosed with post-COVID-19 condition, were randomly assigned to an experimental group (rehabilitation plus incentive spirometer, n = 41) or a control group (rehabilitation alone, n = 41). METHODS: Eight outcomes were assessed at baseline and 1 month, including peak expiratory flow, Medical Research Council dyspnoea scale, EQ-5D-5L, and functional performance tests. RESULTS: Both groups improve at 1-month follow-up. The experimental group showed greater improvements in peak expiratory flow (between-group difference = 65.85 L/min; 95% CI: 4.35 to 127.35; p = 0.007), and dyspnoea (MRC difference = -1.08; 95% CI: -1.54 to -0.62; p < 0.001) compared with the control group. No significant between-group differences were observed for quality of life or functional performance measures. CONCLUSION: Adding incentive spirometry to standard rehabilitation improved peak expiratory flow and reduced dyspnoea in adults with post-COVID-19 condition, supporting its use as a low-cost adjunct for respiratory symptom management.