The Chronic Pain Grade Questionnaire: validity, reliability and responsiveness in Greek chronic hip pain sufferers

The Chronic Pain Grade Questionnaire (CPGQ) was developed to assess the global severity of chronic pain based on pain intensity and pain-related disability. This study aimed to translate, culturally adapt, and validate the Greek version of the CPGQ (CPGQ-Gr).  Methods: Adaptation into Greek followed established guidelines. We invited orthopedic outpatients suffering from chronic hip pain to participate in the study. The validity, reliability, and responsiveness of the CPGQ-Gr were assessed.

Factor analysis yielded two factors (subscales), disability score (DS) and characteristic pain intensity (CPI). CPGQ-Gr items, total and subscale scores were highly correlated with the 12-Item Short Form Health Survey (SF-12) physical component summary score, and slightly correlated or not correlated with the SF-12 mental component summary score. Cronbach's alpha correlation coefficients for the CPGQ-Gr total scale, DS, and CPI subscales were 0.90, 0.95, and 0.83 respectively. All measures showed excellent temporal stability (intraclass correlation coefficients of 0.84, 0.92, and 0.91, respectively). Cliff's delta effect sizes ranged from 0.47 to 0.82. The values of the area under the receiver operating characteristic curve were consistent with good to excellent discriminatory ability (range: 0.747-0.902).

Our findings suggest that the Greek version of the CPGQ is a valid, reliable, and sensitive to changes, instrument for grading the severity of chronic hip pain. HIPPOKRATIA 2018, 22(1): 37-42.