Functional assessment in patients with chronic pain: can physicians predict performance?

OBJECTIVES

To determine the appropriateness of using physicians to estimate the functional abilities of patients with chronic pain. Specific objectives included the following: (1) to compare the physician's predicted performance on functional assessment with actual performance, and (2) to compare the physician's predicted effort during functional assessment with an objective measure of effort.

DESIGN

A total of 201 outpatients with chronic pain completed this prospective, multicenter, cohort study. Fifteen physicians, who were trained to administer the standardized evaluation, performed the evaluations and predicted performance and effort on functional assessment. Therapists, blinded to the physician's evaluation, administered a functional assessment (maximal and sustained lifts [n = 3 types]; repetitive activities [n = 4 types]) and a grip dynamometry test (effort measure) on each subject.

RESULTS

Pearson's correlation testing demonstrated significant correlations between the physician's predicted performance and the observed performance for all lifting items and repetitive activities in both men (0.52, 0.50, 0.55) and women (0.36, 0.40, 0.18). Analysis of variance and post hoc t tests showed agreement between the physician's predicted effort and the dynamometry effort measure in only a small subset of patients (men were predicted to put forth absolutely no effort; n = 4).

CONCLUSIONS

A trained physician, performing a standardized evaluation, can estimate with reasonable accuracy the work-related functional ability in patients with chronic pain. The prediction of effort seems to be more problematic.