Translation, cultural adaptation and validation of the Current Opioid Misuse Measure (COMM) for European Portuguese

Abstract

Background: The Current Opioid Misuse Measure (COMM) is a questionnaire that helps physicians to screen aberrant opioid-related behaviors in chronic pain patients. The aim of this study was to translate, adapt and validate the COMM for European Portuguese. Methods: The translation and cultural adaptation process followed guidelines and a model of principles for good practice. Eligible patients who visited our chronic Pain Unit were invited to complete the translated Portuguese version of COMM. We enrolled patients aged 18 or older, who had chronic pain and were currently on opioid therapy for at least one month. A retest was performed later. Regarding statistical methods, descriptive statistics, Cronbach’s alpha coefficient, inter-item and item-total correlations, intra-class correlation coefficients and principal components analysis were used. Results: Ninety-eight patients completed the study. The median age was 62.5 (55.0 73.0) years and a wide variety of opioids was being used. A global Cronbach’s alpha of 0.778 was found. Cronbach’s alpha would increase if questions number 12 and 17 were removed but other criteria need to be taken in account. An intra-class correlation coefficient of 0.90 (95% CI= 0.76-0.96) was found between test and retest. Six principal components were extracted and they explained 66.3% of the variance. Discussion and Conclusion: The Portuguese version of COMM demonstrated a good quality in terms of internal consistency, validity and test-retest reliability. Therefore, this translation is expected to help physicians in the screening of aberrant opioid-related behaviors in Portuguese chronic pain patients.