Effectiveness of hyperbaric oxygenation therapy in post-stroke dysphagia: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials

Abstract

To investigate the effectiveness of hyperbaric oxygen in treating Post-Stroke dysphagia using meta-analysis and trial sequential analysis (TSA). A comprehensive search was conducted through 8 databases: Scopus, PubMed, Cochrane, Embase, Web of Science, CNKI, VIP, and Wanfang, until 1 May 2026. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We assessed methodological quality with the Cochrane risk-of-bias tool. 14 RCTs involving 1114 participants were included. Results showed: Swallowing function scales (lower scores indicate improvement): Standardized Swallowing Assessment (SSA): SMD = − 0.81, P < 0.00001. Video Fluoroscopic Swallowing Study (VFSS): MD = 1.60, P = 0.0003. Water Swallowing Test (WST): MD = − 1.27, P = 0.0001. Clinical Effective Rate (proportion of patients achieving ≥ 2-point improvement or returning to oral feeding): RR = 1.28, P < 0.0001. Quality of life and intake (higher scores indicate improvement): Swallowing Quality of Life (SWAL–QOL): MD = 1.11, P = 0.04. Functional Oral Intake Scale (FOIS): MD = 1.17, P < 0.0001. National Institutes of Health Stroke Scale (NIHSS): MD = − 5.85, P < 0.00001. Risk of bias was reported by domain. GRADE certainty of evidence ranged from very low to low due to heterogeneity and risk of bias. Adjunctive HBO may improve swallowing function and related outcomes in PSD, but the clinical certainty is limited by methodological weaknesses, heterogeneity, incomplete reporting of intervention parameters, and insufficient TSA information size for several patient-centered outcomes.