Effect of Supervised Exercise, Home-based Exercise and Endovascular Revascularization on Physical Activity in Patients with Intermittent Claudication: A Network Meta-analysis

Abstract

Introduction: It is unclear whether intermittent claudication (IC) treatments have a meaningful impact on physical activity, despite extensive research on their effect on walking performance. Successful treatment of claudication symptoms may fail to influence inactive behaviour. This was a network meta-analysis to compare the effect of supervised exercise therapy (SET), home-based exercise therapy (HBET) and endovascular revascularization (ER) on daily physical activity in IC patients. Methods: Multiple databases were searched systematically from inception to April 2018. Randomized controlled trials with IC patients were eligible for inclusion if they harboured both baseline as well as follow-up assessments of an objective measure of free-living physical activity (i.e. using an accelerometer or pedometer). A Bayesian network meta-analysis was performed to combine direct evidence from standard random-effects meta-analysis with indirect treatment comparisons in a single analytical framework. The primary outcome of interest was the comparative change in physical activity between treatments (SET, HBET, ER) and control (no treatment). The standardized mean difference (SMD) with 95% credible interval (CI) was calculated as a summary statistic, and converted into steps per day. The GRADE working group approach was used to rate quality of the evidence underlying the effect estimates. Results: A total of 9 trials involving 687 IC patients were included in the primary meta-analysis. Four trials evaluated SET versus control, two trials compared HBET with control, two trials evaluated HBET versus SET versus control, and one trial compared ER to SET and control (Figure 1). Both SET (SMD 0.50, 95% CI 0.17 – 0.87; 873 steps/day) and HBET (SMD 0.56, 95% CI 0.17 – 1.01; 978 steps/day) displayed a benefit on daily physical activity over control, based on evidence of moderate and low quality, respectively. The benefit of ER compared to control was SMD 0.44 (95% CI -0.28 – 1.21; 768 steps/day), but only one trial supplied direct evidence, resulting in a low rating of the quality of evidence. Comparisons between treatments yielded no statistically significant differences. Conclusion: SET likely leads to a moderate improvement of physical activity in patients with IC compared to control therapies after three to six months. HBET and ER may have similar benefits, but based on low quality evidence. Furthermore, comparisons for ER failed to reach statistical significance. In general, the effects of IC treatments on physical activity are not well studied impeding definite comparisons.