Tyler EJ, Jensen MP, Engel JM, Schwartz L. The reliability and validity of pain interference measures in persons with cerebral palsy. Arch Phys Med Rehabil 2002;83:236-9. Objective: To evaluate the reliability and validity of 2 measures of pain interference in persons with cerebral palsy (CP). Design: Standardized interviews to assess pain and impact of pain on activities. Setting: University medical center. Participants: Fifty adults with CP. Interventions: Patients asked to rate pain's intensity, interference with general activities, and depression levels. Main Outcome Measures: 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. Results: 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 α =.59), whereas that of the 10 BPI items was excellent (.89). Conclusions: The pain interference items of the BPI serve as a reliable and valid measure of pain's impact on persons with CP-related pain. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation