Comparative effectiveness of water-based versus land-based rehabilitation in COPD: a systematic review and network meta-analysis of randomized controlled trials.

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality. Pulmonary rehabilitation (PR) is central to COPD management; however, individuals with musculoskeletal limitations, obesity, or reduced tolerance to land-based rehabilitation (LBR) may benefit from water-based rehabilitation (WBR). To evaluate the comparative effectiveness of WBR, LBR, and control interventions on exercise capacity (EC) and health-related quality of life (HRQoL) in adults with COPD using a systematic review and network meta-analysis (NMA). Randomized controlled trials (RCTs) involving adults with COPD were searched in PubMed, Cochrane Library, PEDro, and Bibliothèque nationale du Luxembourg from inception to July 13, 2025. The primary outcomes were EC, measured using the 6-Minute Walk Test (6MWT), Incremental Shuttle Walk Test (ISWT), and Endurance Shuttle Walk Test (ESWT), and HRQoL, assessed using the Chronic Respiratory Disease Questionnaire (CRDQ) and St. George's Respiratory Questionnaire (SGRQ). The Risk of bias was assessed using the Risk of Bias 2.0 tool (RoB 2.0). A frequentist NMA was used to estimate the comparative effects and intervention rankings. The certainty of the evidence was rated using the Grading of Recommendations, Assessment, Development, and Evaluations approach (GRADE). Nine RCTs (n = 323) were included in the analysis. WBR was associated with clinically meaningful improvements in EC, particularly in endurance performance (ESWT) and shuttle walking (ISWT), with several effects exceeding the established minimal clinically important difference (MCID) thresholds. HRQoL outcomes were heterogeneous: WBR improved selected CRDQ and SGRQ domains, whereas LBR ranked highest for overall HRQoL. The NMA ranking suggested that WBR had the highest probability of being the most effective intervention for EC and combined EC+HRQoL outcomes, whereas LBR ranked highest for HRQoL alone. Heterogeneity was low for EC, moderate for HRQoL, and high for the combined outcomes. The certainty of evidence ranged from moderate (EC) to low (combined outcomes). WBR is a viable alternative to LBR for improving EC in individuals with COPD and may be particularly beneficial for those with reduced mobility or limited tolerance to land-based training. However, given the limited number of trials and variability across studies, these findings should be interpreted with caution. High-quality and adequately powered RCTs are required to confirm the long-term effects and real-world applicability of these findings.