Psychometric Evaluation of the Persian-Abbey Pain Scale (P-APS) in a Sample of Iranian Elderly with Dementia: A Cross-Sectional Study

Background and Objectives: Considering the problem of pain expression by the elderly with dementia, assessment and determination of its severity in this group require an appropriate scale. The present study was conducted with the aim of translation and psychometric evaluation of the Abbey Pain Scale (APS) in Iranian elderly with dementia. Materials and Methods: In this cross-sectional study of psychometric evaluation of scale, after translating and assessing the face and content validity of APS, 100 eligible elderly were selected by convenience sampling in Kashan, 2018-19. Construct validity was assessed by exploratory factor analysis, known-groups approach, and convergent validity. Reliability was assessed by internal consistency, equivalence, and stability. Data were analyzed by Wilcoxon and Mann–Whitney tests, Cronbach's alpha, Spearman-Brown, and Intraclass Correlation Coefficient (ICC). Results: The scale content validity index was 0.95%, and the item impact of each item was above 1.5. Factor analysis identified a single-factor in APS that was able to explain 68.745% of the total variance of scale score. This scale was able to differentiate between scores during two resting positions and movement protocol, and between two groups with known painful diseases and non-diseased (p<0.0001). There was a significant positive correlation between scores of the Persian version of APS and PACSLAC-II-IR (r=0.877, p<0.0001). Cronbach's alpha, ICC, and standard error of measurement of the scale were calculated 0.927, 0.926, and ±1.191, respectively. Conclusions: The Persian version of APS can be used as a valid and reliable scale for assessing pain in the elderly with dementia in Iran. Key words: Weights and measures, Aged, Dementia, Pain, Psychometrics, Abbey Pain Scale   Funding: This study was funded by Vice Chancellor for Research and Technology of Kashan University of Medical Sciences, Kashan, Iran. Conflict of interest: None declared. Ethical approval: The Ethics Committee of Kashan University of Medical Sciences approved the study (IR.KAUMS.NUHEPM.REC.1397.015).   How to cite this article: Zare M, Tagharrobi Z, Sharifi Kh, Sooki Z, Abolhasani J. Psychometric Evaluation of the Persian-Abbey Pain Scale (P-APS) in a Sample of Iranian Elderly with Dementia: A Cross-Sectional Study. J Rafsanjan Univ Med Sci 2020; 19 (1): 3-22. [Farsi]