A systematic review protocol for slow-paced breathing in healthy populations: Impacts on cognition and insights into mechanisms of action

Abstract Background Slow-paced breathing (SPB) has emerged as an intervention to improve cognitive function and prevent cognitive decline. The proposed systematic review aims to consolidate previous literature examining the impacts of SPB across cognitive subdomains when compared to passive and active controls in adults, as well as the mechanisms involved. Methods Literature searches will be conducted in MEDLINE(R) ALL, Embase Classic + Embase, Cochrane Central Register of Controlled Trials, PsycINFO, CINAHL Ultimate, and Web of Science. Gray literature sources include preprints and clinical trial registries. Citation tracking will be used as a supplemental search method. RCTs, quasi-randomized trials, and non-randomized interventions with a control or comparison group focused on adult human participants will be included. Studies on pediatric populations or animals will be excluded. The primary outcomes are standardized cognitive test scores and test batteries. Data on the parameters of SPB protocols will also be collected to gain insight into the mechanisms driving observed cognitive changes. Two independent reviewers will blindly complete citation screening, data extraction, risk-of-bias assessment using Covidence, and appraisal of study quality using GRADEpro. Risk of bias will be assessed for non-randomized controlled trials and RCTs using the ROBINS-I and RoB tools, respectively. A narrative synthesis of the findings will be conducted. Results will be stratified based on methodological features such as study design, population demographics, intervention parameters, and cognitive domain. If the data of the included literature permit, a meta-analysis will be performed to compare improvements by (i) cognitive domain, (ii) population demographics, and (iii) parameters of intervention protocols (e.g., duration of inhalation vs. exhalation). Discussion SPB is a promising intervention for conferring generalizable cognitive improvements. This review will consolidate early findings, give insight into SPB’s efficacy as a clinical intervention, and lay the groundwork for future research into mechanisms and optimal parameters. Systematic review registration PROSPERO CRD42024615253