Assessment of Pain in Adults with Intellectual and Developmental Disabilities

Abstract

Background: Pain measurement is a challenging task in most populations, but individuals with intellectual and developmental disabilities (IDD) display specific barriers to adequate pain evaluation, since they cannot give valid self-reports. Despite enhanced interest in manifestations of pain in adults with IDD in recent years, the characteristics of pain behavior in this group have scarcely been examined. Aims: The aim of this thesis was to develop a clinical tool for assessing pain behaviors in adults with intellectual and developmental disabilities (IDD), to test the scale in respect to reliability and validity, and to test its clinical applicability in a painful situation with the research population. Population: A total of 266 adults (mean age: 42.2 years) with different levels of IDD, living in community and residential centers were included in the study. Method: In Paper I the Non-Communicating Children’s Pain Checklist (NCCPC) and the Facial Action Coding System (FACS)'s ability to capture pain behavior in adults with IDD was examined. All participants were videotaped before and during an annual influenza vaccination, and scored using the NCCPC and FACS on both occasions. In Paper II based on scores from the video uptakes, the sensitivity to pain of each test item of the NCCPC (total of 27 items) was examined by Signed rank test, and contribution of each item to internal consistency was examined by Cronbach’s alpha. Sensitivity to change of the total scale by Standardized Response Mean (SRM) was evaluated. Thirteen items were excluded from the original NCCPC scale while four new items were added, making a modified scale named the Non-Communicating Adults' Pain Checklist (NCAPC). The internal consistency and sensitivity of the scale was reexamined after the reduction of items. In Paper III intra- and interrater reliability of the NCAPC were investigated on video vignettes. Intrarater reliability was evaluated by the first author on a group of 50 randomly selected individuals. Interrater reliability was investigated in two stages. In the initial step different groups of health care workers (caregivers, nurses, case managers, and therapists), each including five raters, viewed a sample of 12 adult participants with IDD (3 at each level of IDD), who were extracted from the population sample. In the second stage 3 participants from each of the groups showing high interrater reliability (caregivers and therapists) evaluated interrater reliability in a randomly selected group of 40 individuals. In paper IV the NCAPC's was examined in clinical settings for internal consistency, validity and clinical usability. To achieve these aims 58 adults at all levels of IDD, receiving dental hygiene treatment, were observed for pain behavior, before and during dental hygienist treatment, using the NCAPC. The results were compared with scores of the same participants during an influenza injection. Results: The results from paper I suggested that The NCCPC was superior to the FACS in capturing pain behavior in adults with IDD and was sensitive to pain behaviors at all levels of IDD, and development of a new scale was continued with NCCPC. In paper II The scale was named the Non-Communicating Adults Pain Checklist-Revised (NCAPC). All items remaining in the modified scale were found to show Sensitivity to pain (P<0.05) and high internal consistency (α=0.773) was demonstrated. Large sensitivity to pain at all levels of IDD was shown (SRM 1.20- 2.07). The NCAPC was found to demonstrate better measurement properties than the NCCPC-R in the target population. In paper III intrarater reliability was found at 0.94. Interrater reliability was very high in caregivers, physical- and occupational therapists, and was found at 0.91 and 0.92, correspondingly. Results of paper IV show that the NCAPC was affective in assessing pain behaviors in a clinical setting. The scale showed satisfactory internal consistency, was able to differentiate between pain and non-pain situations and different pain experiences (influenza injection, dental hygienist treatment). Discussion: Findings from Paper I showed that the NCCPC should be used as a basis to further development of a pain assessment tool for adults with IDD. Other findings suggested that some pain behaviors were commonly observed in adults, but not sufficiently captured by the NCCPC. Therefore there seemed to be a need to adapt the NCCPC to the adult IDD population. In paper II it was established that the NCAPC was showing better psychometric properties than NCCPC in adults with IDD. In paper III we concluded that the NCAPC have been found to hold high intra- as well as inter-rater reliability values. In paper IV The NCAPC was found a valid and reliable tool, and the authors concluded that it can be used clinically to detect acute pain behaviors of individuals at all levels of IDD at different settings by different health care workers, and during various pain experiences. Summation: The procedure that was performed in the present thesis has led to the construction of a pain behavior evaluation scale for adults with intellectual disability, showing good measurement properties that allow the use of this tool in clinical settings.