Table IV.

Multiple regression models between the log transformed exercise time to the minimum calf muscle StO₂ (predictor) and clinical exercise outcome variables in 151 symptomatic patients with peripheral artery disease.

Clinical Exercise Outcome Variables	Model	Estimate (95% CI)	Partial R2	P Value	AIC	Overall R2
Claudication Onset Time	1	67.50 (48.32, 86.67)	0.24	< 0.001	1927.3	0.24
	2	64.81 (45.63, 83.98)	0.22	< 0.001	1929.5	0.26
	3	67.81 (48.64, 86.98)	0.23	< 0.001	1920.7	0.29
	4	65.56 (46.39, 84.73)	0.22	< 0.001	1920.4	0.31
Peak Walking Time	1	125.26 (95.68, 154.84)	0.32	< 0.001	2058.2	0.32
	2	120.17 (90.59, 149.75)	0.29	< 0.001	2053.0	0.37
	3	125.00 (95.42, 154.58)	0.32	< 0.001	2040.9	0.40
	4	120.33 (90.76, 149.91)	0.31	< 0.001	2032.4	0.44
6-Minute Walk Pain-Free Distance *	1	0.11 (0.02, 0.20)	0.04	0.018	296.7	0.04
	2	0.09 (−0.01, 0.18)	0.02	0.073	296.0	0.08
	3	0.10 (0.01, 0.19)	0.03	0.045	296.9	0.12
	4	0.08 (−0.01, 0.18)	0.02	0.081	296.7	0.14
6-Minute Walk Distance	1	25.36 (12.54, 38.18)	0.09	< 0.001	1749.8	0.09
	2	22.93 (10.11, 35.76)	0.08	< 0.001	1738.2	0.20
	3	26.14 (13.32, 38.96)	0.11	< 0.001	1721.3	0.27
	4	23.26 (10.44, 36.08)	0.10	< 0.001	1708.4	0.35
Total Daily Steps	1	210.40 (−22.29, 443.10)	0.02	0.078	2662.7	0.02
	2	155.27 (−77.42, 387.96)	0.01	0.212	2665.1	0.04
	3	201.11 (−31.58, 433.80)	0.02	0.100	2641.7	0.13
	4	163.33 (−69.37, 396.02)	0.01	0.180	2639.8	0.16
Moderate-to-Vigorous Daily Steps	1	113.99 (22.68, 205.30)	0.04	0.016	2382.1	0.04
	2	81.08 (−10.23, 172.39)	0.02	0.095	2382.2	0.08
	3	95.84 (4.53, 187.15)	0.03	0.046	2363.4	0.14
	4	86.90 (−4.41, 178.21)	0.02	0.072	2363.5	0.16
WIQ Distance Score	1	9.03 (4.93, 13.12)	0.11	< 0.001	1461.3	0.11
	2	8.28 (4.18, 12.38)	0.09	< 0.001	1460.2	0.15
	3	8.64 (4.55, 12.74)	0.10	< 0.001	1455.9	0.17
	4	7.96 (3.86, 12.06)	0.09	< 0.001	1447.6	0.23
WIQ Speed Score	1	7.65 (4.71, 10.60)	0.15	< 0.001	1361.3	0.15
	2	7.18 (4.23, 10.12)	0.13	< 0.001	1360.6	0.19
	3	7.63 (4.69, 10.58)	0.14	<0.001	1355.2	0.21
	4	7.27 (4.33, 10.21)	0.14	< 0.001	1349.6	0.26
WIQ Stair Climbing Score	1	9.30 (5.59, 13.00)	0.14	<0.001	1421.6	0.14
	2	7.89 (4.18, 11.59)	0.11	< 0.001	1403.3	0.27
	3	8.15 (4.44, 11.86)	0.12	< 0.001	1396.1	0.30
	4	8.11 (4.40, 11.81)	0.12	< 0.001	1398.7	0.30
MOS SF-36 Physical Function Score	1	5.40 (2.80, 8.00)	0.10	< 0.001	1323.7	0.10
	2	4.54 (1.95, 7.14)	0.07	< 0.001	1313.0	0.19
	3	4.65 (2.05, 7.25)	0.08	< 0.001	1307.3	0.22
	4	4.33 (1.74, 6.93)	0.07	0.002	1306.7	0.24

^*Log transformed data, AIC = akaike information criterion, MOS SF-36 = Medical Outcomes Study Short-Form 36 survey, StO₂ = hemoglobin oxygen saturation ,WIQ = walking impairment questionnaire.

Model 1: unadjusted. Model 2: adjusted for age, sex, race. Model 3: adjusted for Model 2 plus body mass index, smoking, hypertension, diabetes. Model 4: adjusted for Model 3 plus ankle-brachial index.