Pain measurement in the older people: evaluation of the psychometric properties of the Geriatric Pain Measure (GPM-24) – Polish version

Abstract

Abstract Background Chronic pain in older people is of particular importance not only with regard to negative subjective experience but also as an indicator of the quality of medical care. Brief scales to assess pain may help health professionals with early recognition and treatment to avoid patient suffering. However, these scales should be adapted to the cultural context to provide valid assessments. The aim of this study was to evaluate the psychometric properties of the Polish translation of the Geriatric Pain Measure – 24 (GPM-24) in older people. Methods The study was conducted among 181 people aged 65 and over with chronic (noncancer) pain of varying intensity lasting more than 6 months. Construct validity was assessed using the principal component analysis (PCA) method with oblimin rotation. Criterion validity was evaluated by correlating the scores of the GPM-24 with the scores of the McGill-Melzack questionnaire (MPQ). The reliability of the GPM-24 was estimated in terms of internal consistency using Cronbach’s alpha coefficients. Results The PCA revealed a 6- component structure of the set of items that constituted the GPM-24. Most of these components were defined by items included in the same subscale, similar to the result obtained by the original scale’s authors. There were significant correlations between the GPM-24 and some dimensions of MPQ: affective (rho = 0.25, p = 0.001), present pain intensity (rho = 0.44, p < 0.001), pain rating index total (rho = 0.31, p < 0.001), and number of words chosen (rho = 0.26, p < 0.001). The value of the standardized Cronbach’s alpha equalled 0.89 and thus confirmed the high reliability of the GPM-24. Conclusions The Geriatric Pain Measure − 24 is a reliable and valid tool that is recommended for the monitoring and multidimensional assessment of chronic pain in older people in daily practice as well as in clinical trials. Trial registration Statutory research “Chronic pain in people over 65 years of age” K/ZDS/005733, conducted in 2015–2018.