Table 3.

Concurrent and Convergent Validity of the Pittsburgh Fatigability Scale Physical Fatigability Score with Performance Fatigability, Mobility, Physical Function, and Fitness

Performance Measure	Adjusted Physical Fatigability Score Mean (Standard Error)a		Adjusted Mean Difference	P-Value	Area Under the Receiver Operating Characteristic Curve (95% Confidence Interval)
	Yes	No
High perceived exertion (n = 123, 27%)b	18.3 (1.7)	13.2 (1.5)	5.1	<.001	0.73 (0.68–0.79)
High performance deterioration (n = 82, 18.1%)c	17.3 (1.8)	14.2 (1.6)	3.1	<.001	0.68 (0.61–0.74)
Slow gait speed (n = 101, 21.9%)d	17.3 (1.7)	13.8 (1.6)	3.5	<.001	0.76 (0.68–0.84)
Worse physical function (n = 111, 25%)e	16.6 (1.7)	13.3 (1.6)	3.2	<.001	0.67 (0.61–0.73)
Lower fitness (n = 117, 25%)f	17.4 (1.6)	12.3 (1.6)	5.1	<.001	0.74 (0.69–0.80)

^aAdjusted for age, sex, and race.

^bDefined as rating of perceived exertion ≥10 at the end of 5-minute treadmill walk at 0.67 m/s.

^cDefined as ≥6.5% slower lap time between Laps 9 and 2 from the long-distance corridor walk.

^dUsual gait-speed <1.0 m/s from fastest of two 6-m walks.

^eHighest quartile (>13.58 s) of time to complete five chair stands.

^fHighest quartile (≥307.1 s) of time to complete fast-paced 400-m walk.