Further Clinical Validation of the Walking Impairment Questionnaire for Classification of Walking Performance in Patients with Peripheral Artery Disease

Table 2

WIQ scores categorized by treadmill walking performance as measured by the ACD.

	n	Low		Medium		High		All		P
		Mean	SD	Mean	SD	Mean	SD	Mean	SD
Absolute claudication distance (meters)	123	103.0	32.0	296.8	79.2	849.9	423.0	416.5	402.5	<0.0001^*
Peak walking time (seconds)	123	137.6	36.0	354.4	88.6	973.0	473.1	488.4	450.2	<0.0001^*
WIQ-distance	119	18.3	19.4	38.4	25.3	59.7	27.8	39.5	30.2	<0.0001^*
WIQ-speed	119	27.9	20.6	49.9	25.8	61.3	24.9	47.6	28.0	<0.0001^†
WIQ-stair	109	37.5	21.3	61.4	26.9	73.8	23.0	58.0	27.8	<0.0001^†
WIQ-distance and speed	115	23.2	19.2	44.6	22.0	60.1	23.7	39.5	30.2	<0.0001^*
WIQ-overall	102	26.9	13.8	52.0	21.2	65.0	20.6	47.6	28.0	<0.0001^*

SD: standard deviation.
Low (<159.89 meters), medium (159.89–415.89 meters), high (>415.89 meters) categories are based on thirds of the population divided by tertiles of ACD.
P  value: ANOVA test.
^*Significant difference between all groups using Bonferroni method.
^†Significant difference between all groups except medium and high using Bonferroni method.
Note: sample sizes vary for each subscore based on the number who had fewer than half missing values for that subscores. If any of the subscores were missing the overall score was coded as missing.