Table 2.
Correlations of Disease-specific Quality of Life Change with Treadmill Parameter (Peak Walking Time, Claudication Onset Time) and Community-based Walking (7-Day Community Steps) Change at 6 Months after Treatment
| Correlation of Change in QOL with Changes in PWT across Treatment Groups | |||||||
|---|---|---|---|---|---|---|---|
| SE |
ST |
OMC |
|||||
| QOL Scale | Treatment Group Interaction (P Value) | Parameter Estimate and 95% CI | P Value | Parameter Estimate and 95% CI | P Value | Parameter Estimate and 95% CI | P Value |
| PAQ physical limitation | .01* | 0.95 (−0.59, 2.49) | .21 | 3.5 (2.0, 5.1) | < .001* | 1.6 (−2.1, 5.3) | .37 |
| PAQ summary | .09* | 0.89 (−0.21, 2.01) | .11 | 2.2 (0.8, 3.5) | .003* | 0.56 (−2.86, 3.97) | .74 |
| PAQ symptoms | .08* | 0.33 (−1.06, 1.73) | .629 | 2.2 (0.7, 3.7) | 006* | −0.18 (−3.49, 3.13) | .91 |
| WIQ distance | .003* | 0.49 (−0.26, 1.24) | .19 | 2.3 (1.4, 3.3) | < .001* | 1.2 (0, 2.3) | .05* |
| WIQ speed | .02* | 1.6 (0.4, 2.8) | .009* | 4.2 (2.7, 5.8) | < .001* | 0.22 (−2.96, 3.40) | .886 |
| Correlation of Change in QOL with Changes in COT across Treatment Groups | |||||||
| PAQ physical limitation | .38 | 2.7 (0.4, 4.9) | .02* | 3.8 (2.0, 5.6) | < .001* | 1.9 (−7.1, 10.9) | .66 |
| PAQ summary | .12 | 1.2 (−0.5, 3.0) | .17 | 3 (1, 5) | < .001* | 5.4 (−2.6, 13.3) | .17 |
| PAQ symptoms | .2 | 1.3 (−0.9, 3.5) | .24 | 3.2 (1.5, 4.9) | < .001* | 4.4 (−3.2, 12.1) | .24 |
| WIQ distance | .85 | 1.8 (0.7, 2.8) | .002* | 2.4 (1.3, 3.5) | < .001* | 1.7 (−1.1, 4.6) | .22 |
| WIQ speed | .35 | 2.6 (0.7, 4.5) | .008* | 4 (2, 6) | .002* | 1.8 (−5.1, 8.7) | .58 |
| Correlation of Change in QOL with Changes in PED across Treatment Groups | |||||||
| PAQ physical limitation | .946 | 0.03 (−0.03, 0.09) | .333 | 0.03 (−0.01, 0.08) | .12 | −0.02 (−0.18, 0.13) | .72 |
| PAQ summary | .82 | 0.01 (−0.03, 0.05) | .599 | 0.02 (−0.01, 0.05) | .204 | −0.00138 (−0.10724, 0.10448) | .978 |
| PAQ symptoms | .866 | 0.01665 (−0.03813, 0.07142) | .535 | 0.02262 (−0.01377, 0.05902) | .212 | 0.06152 (−0.02920, 0.15224) | .162 |
| WIQ distance | .59 | 0.00581 (−0.03175, 0.04337) | .75 | 0.03 (0, 0.05) | .044* | 0.0022 (−0.0437, 0.0480) | .92 |
| WIQ speed | .79 | 0.007 (−0.048, 0.062) | .788 | 0.018 (−0.029, 0.064) | .438 | −0.006 (−0.099, 0.088) | .897 |
Correlations of disease-specific QOL change with PWT change showed an interaction effect with treatment group, with statistically significant interaction effects for all five scales. Improvements in QOL scales are much more modest for SE when PWT improved compared with ST and for SE were not statistically significant but for ST were highly statistically significant. No interactions with treatment groups were noted for the correlations of COT or PED with QOL scales, but the parameter estimates were much larger for ST than SE for COT.
CI = confidence interval, COT = claudication onset time, OMC = optimal medical care, PAQ = Peripheral Artery Questionnaire, PED = 7-day community steps, PWT = peak walking time, QOL = quality of life, SE = supervised exercise, ST = stent revascularization, WIQ = Walking Impairment Questionnaire.
Statistically significant correlations between baseline QOL and PWT, COT, or PED.