The Patient-Specific Functional Scale: Validity in Workers' Compensation Claimants
published online 05 June 2008.
Abstract
Gross DP, Battié MC, Asante AK. The Patient-Specific Functional Scale: validity in workers' compensation claimants.
Objective
To examine the construct and predictive validity of the Patient-Specific Functional Scale (PSFS) in workers' compensation claimants.
Design
Prospective cohort study with 1-year follow-up.
Setting
A workers' compensation rehabilitation facility.
Participants
Subjects included 294 claimants with a variety of musculoskeletal disorders. The sample was predominantly male (70%), with a mean age of 44 years. Subjects completed a battery of measures at baseline including the PSFS, the Pain Disability Index (PDI), and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36).
Interventions
Not applicable.
Main Outcome Measures
Outcomes for determining predictive validity included administrative indicators of timely return to work and recovery during the 1-year follow-up. Analysis included Pearson correlation and multivariable Cox and logistic regression.
Results
At baseline, the PSFS correlated moderately (r range, 0.3−0.5) with other indicators of functional limitation (PDI, SF-36 role−physical subscale) but negligibly with the SF-36 mental health and role−emotional subscales. The PSFS was associated with timely recovery (adjusted hazard ratio, 1.16; 95% confidence interval, 1.07–1.27) with increasing functional limitation related to delayed recovery.
Conclusions
Results provide construct and predictive validity evidence for the PSFS as an indicator of functional limitation in workers' compensation claimants.
aDepartment of Physical Therapy, University of Alberta, Edmonton, AB, Canada
bWorkers' Compensation Board in Alberta/Millard Health, Edmonton, AB, Canada
cPeter Lougheed Centre, Calgary Health Region, Calgary, AB, Canada.
Reprint requests to Douglas P. Gross, PhD, 2-50 Corbett Hall, University of Alberta, Edmonton, AB T6G 2G4, Canada
Supported by the University of Alberta Department of Physical Therapy, Alberta Physical Therapy Association, and the Canada Research Chairs Program.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.
ABSTRACT