Effect of behaviour change interventions on walking capacity, clinical outcomes, and quality of life in intermittent claudication: insights from the OPTIMA systematic review and meta-analysis

Background/Introduction
Intermittent claudication (IC) significantly impairs mobility and quality of life in individuals with peripheral artery disease. Interventions incorporating behaviour change techniques (BCTs) have been proposed to improve walking capacity and overall well-being in this population. This is a report on the secondary outcomes of a systematic reviews and meta-analyses of BCT-based interventions in individual with intermittent claudication.

Purpose
To evaluate the impact of BCT-based interventions on walking capacity (absolute claudication distance [ACD], initial claudication distance [ICD], six-minute walk test [6-MWT]), clinical outcomes (ankle brachial index [ABI], cardiovascular risks, disease progression, mortality), and quality of life in individuals with IC.

Methods
A systematic search of 11 databases was conducted from inception to November 2022, with alerts of newly published articles until August 2024. Randomised controlled trials (RCTs) comparing BCT-based interventions to SET or non-SET controls were included. Short- (6 months) and medium-term (≥6 months) outcomes were analysed using pairwise random-effects meta-analysis. Mean differences were calculated for continuous outcomes, standardised mean differences (SMD) for multi-measure outcomes, and risk ratios for binary outcomes. Heterogeneity was assessed via forest plots, I², and Tau estimates. Study quality was assessed using the Risk of Bias 2 tool.

Results
Twenty-six RCTs (3,357 participants, mean age 60.3–73.8 years) were included. Walking Capacity: Compared to non-SET interventions, BCT-based interventions improved ACD by 39m (SMD 0.42, 95% CI: 0.22–0.61) and ICD by 73m (SMD 0.54, 95% CI: 0.36–0.72) in the short term. Medium-term gains were 16m (ACD) and 32m (ICD). 6-MWT improved by 26m (95% CI: 6–46) in the short term, though medium-term results were inconclusive. Compared to SET, BCT-based interventions were less effective for ACD (SMD -0.43, 95% CI: -0.82 to -0.03), while effects on ICD and 6-MWT were inconclusive. Clinical Outcomes: Limited data prevented definitive conclusions on ABI, cardiovascular risk, or disease progression. One study reported no adverse cardiovascular events; mortality outcomes were unreported. Quality of Life: Compared to non-SET interventions, eight RCTs showed mixed health-related quality of life (HRQoL) results, with unclear short-term effects (SMD 0.17, 95% CI: -0.05–0.39) and minimal medium-term impact (SMD 0.08, 95% CI: -0.03–0.19). Disease-specific QoL improved modestly in both short-term (SMD 0.31, 95% CI: 0.13–0.50) and medium-term (SMD 0.32, 95% CI: 0.14–0.50).

Conclusion(s)
BCT-based interventions improve ACD, ICD, and disease-specific QoL compared to non-SET controls in individuals with IC but are less effective than SET for ACD in the short term, with mixed results for ICD, 6-MWT, and QoL. Further research should explore how BCTs can best integrate and complement SET in the management of IC.