Evaluation of three methods to rate impairment in patients with complex regional pain syndrome I of one upper extremity.

OBJECTIVE: To gain insight into the best way of obtaining an impairment rating in complex regional pain syndrome I (CRPS I) of the upper extremity. This syndrome can potentially result in permanent impairment.

DESIGN: Comparison of three evaluation methods to obtain impairment scores. Each patient was seen by one tester; two testers in total participated in the research.

SETTING: Outpatient clinic of a university hospital.

SUBJECTS: Seventy-four patients (27 men, 47 women, mean age 52 years) with CRPS I of one upper extremity.

MAIN OUTCOME MEASURES: Methods I and II were conducted according to the American Medical Association's Guides to the evaluation of permanent impairment method I according to the general guidelines, and method II according to the methodology specificially described for CRPS I. Method III was developed by the Dutch Association of Neurologists. For comparison, differences between methods were plotted against their mean ratings, with the limits of agreement. Also the paired t-statistics were calculated (alpha = 0.05/3).

RESULTS: The mean difference between methods I and II was -0.7% whole body impairment, between methods II and III 8.1% and between methods I and III 7.3%. Outcomes obtained with method III differed significantly from the other outcomes.

CONCLUSIONS: Method I most accurately and objectively reflected the permanent impairment level resulting from CRPS I.