Test-retest reliability on nine tasks of the Physical Work Performance Evaluation

The Physical Work Performance Evaluation (PWPE) is one of many functional capacity evaluations (FCEs) currently available to assist with determining injured workers' physical potential to return to work. Previous research has explored interrater reliability, construct and predictive validity of the PWPE. This research examined test-retest reliability on a sample of 24 clients with stable physical injuries who were participating in vocational rehabilitation. Nine of the 21 main tasks of the PWPE were evaluated: lifting floor to waist, bilateral carrying, pushing, sitting, standing, kneeling, stair climbing, repetitive squatting and walking. Kappa scores ranged from 0.19 (error) to 0.77 and percent agreement from 66.7% to 87.5%. The results for kneeling, lifting floor to waist, bilateral carrying and pushing tasks suggest substantial test-retest reliability with moderate reliability also suggested for the standing and repetitive squatting tasks. Self-limiting behavior and alterations in pain scores, position adjustments and movement deviations are seen to be the main contributors to affect scoring between the first and second tests.