Despite enhanced interest in manifestations of pain in adults with intellectual and developmental disabilities (IDD), the characteristics of pain behavior in this group have seldom been examined. The aim of the present study was to provide a sensitive pain behavior scale for adults with IDD. The participants, 228 adults (mean age, 38.7 years) with different levels of IDD, were videotaped before and during an influenza vaccination and scored using the Non-Communicating Children's Pain Checklist-Revised (NCCPC-R). Observed pain behaviors not captured by the NCCPC-R, was also registered. Sensitivity to pain of all 27 items was examined by Signed Rank test, internal consistency by Cronbach's alpha, and sensitivity to change of the total scale by Standardized Response Mean (SRM). Thirteen items were excluded from the original NCCPC-R scale; 4 new items were added, making a modified scale of 18 items. This scale, named the Non-Communicating Adults Pain Checklist-Revised (NCAPC), was rescored and examined for psychometric properties in a random sample (N = 89). Sensitivity to pain of all items (P < .05) and high internal consistency (alpha = 0.773) were demonstrated. Large sensitivity to pain at all levels of IDD was shown (SRM, 1.20 to 2.07). Better psychometric properties were demonstrated for NCAPC than NCCPC-R in the target population.
Perspective: This article presents initial psychometric properties of a new measure, the NCAPC, evaluating pain behavior in adults with IDD. This measure could help clinicians to better capture pain expressions in this population and contribute to better pain management for this group of patients.