Effect of high-pain versus low-pain structured exercise on walking ability in people with intermittent claudication: meta-analysis

The aim was to determine the comparative benefits of structured high-pain exercise, structured low-pain exercise, and usual-care control, to identify which has the largest effect on walking ability in people with intermittent claudication (IC). A network meta-analysis was undertaken to assess two outcomes: pain-free walking ability (PFWA) and maximal walking ability (MWA). Nine electronic databases were searched. Trials were included if they were: RCTS; involved adults with IC; had at least two of the following arms-structured low-pain exercise, structured high--pain exercise or usual-care control; and a maximal or pain-free treadmill walking outcome. Some 14 trials were included; results were pooled using the standardized mean difference (MD). Structured low-pain exercise had a significant large positive effect on MWA (MD 2.23, 95 percent c.i. 1.11 to 3.35) and PFWA (MD 2.26, 1.26 to 3.26) compared with usual-care control. Structured high-pain exercise had a significant large positive effect on MWA (MD 0.95, 0.20 to 1.70) and a moderate positive effect on PFWA (0.77, 0.01 to 1.53) compared with usual-care control. In an analysis of structured low- versus high pain exercise, there was a large positive effect in favour of low-pain exercise on MWA (MD 1.28, -0.07 to 2.62) and PFWA (1.50, 0.24 to 2.75); however, this was significant only for PFWA. There is strong evidence in support of use of structured high-pain exercise, and some evidence in support of structured low-pain exercise, to improve walking ability in people with IC compared with usual-care control (unstructured exercise advice).