The reliability and validity of pain interference measures in persons with cerebral palsy.

Abstract

To evaluate the reliability and validity of 2 measures of pain interference in persons with cerebral palsy (CP). Standardized interviews to assess pain and impact of pain on activities. University medical center. Fifty adults with CP. Patients asked to rate pain's intensity, interference with general activities, and depression levels. Pain interference scales: Chronic Pain Grade (CPG) and Brief Pain Inventory (BPI); rating of disability: Craig Handicap Assessment and Reporting Technique (CHART); rating of depression: Center for Epidemiologic Studies Depression (CES-D) Scale. Mean interference of pain on 3 CPG items (pain interference with daily activities, social activities, work) were 1.74 +/- 2.45, 1.06 +/- 2.05, and.89 +/- 1.84 (out of 10), respectively. Mean interference on 10 modified BPI interference items ranged from 2.28 +/- 3.01 to 3.67 +/- 3.15 (out of 10). The composite CPG interference score did not correlate significantly with pain intensity. However, the composite BPI interference score did correlate significantly with pain intensity (r = .66, P < .01). There was no significant association shown between average pain and the CHART score (r = -.21, NS). Pain showed a significant association with CES-D score (r = .45, P < .05). Internal consistency of the 3 CPG items was inadequately low (Cronbach alpha = .59), whereas that of the 10 BPI items was excellent (.89). The pain interference items of the BPI serve as a reliable and valid measure of pain's impact on persons with CP-related pain.