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.


METHODS
Prospective cohort study with 1-year follow-up.


METHODS
A workers' compensation rehabilitation facility.


METHODS
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).


METHODS
Not applicable.


METHODS
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.
Department of Physical Therapy, University of Alberta, Edmonton, AB, Canada. dgross@ualberta.ca
Douglas P
DP
Gross
Michele C
MC
Battié
Alexander K
AK
Asante
D000328:Adult; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000534:rehabilitation*; D017063:Outcome Assessment, Health Care; D010147:Pain Measurement; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014481:United States; D014942:Workers' Compensation