Comparing the non-communicating adult pain checklist (NCAPC) with the pain and discomfort scale (PADS) in evaluating pain in adults with intellectual disability

Pain is a difficult phenomenon to measure especially in individuals with intellectual and developmental disabilities (IDD), thereby compromising pain management for this population. Despite that fact, measures that evaluate pain in adults with IDD are scarce. Recently two scales have been constructed to evaluate pain behaviors in adults with IDD, the Non-Communicating Adult's Pain Checklist (NCAPC) and the Pain and Discomfort Scale (PADS). Aim: The aim of the present article was to compare the NCAPC and PADS in evaluating procedural pain in adults with IDD, in regards to reliability, sensitivity, clinical usability and internal consistency. Procedure: 52 vignettes were randomly picked out of a pull of videos of 228 individuals recorded during annual flew vaccination. Two observers separately scored pain behaviors using the PADS and the NCAPC. Results: Both scales showed high interrater reliability (PADS ICC_1,3 = 0.86-0.87, NCAPC ICC_1,3 = 0.81-0.84), Sensitivity to pain behaviors in adults with IDD (SRM PADS = 0.52, SRM NCAPC = 0.57), high correlation among the scales (r₁ = 0.9, r₂ = 0.95), and high internal consistency (PADS α = 0.74-0.78, NCAPC α = 0.78-0.85). Discussion: Most findings are favorable for the NCAPC accept for interrater reliability. These results are probably due to the fact this scale was constructed from this group of client's pain reactions. The fact that both scales show very similar outcomes validate both scales as appropriate for measuring pain in adults with IDD. The fact that two inexperienced observers were able to use both scales and come up with such good psychometric results, support the clinical usability of both scales, hopefully contributing to better pain management in this population.