Short Form-McGill Pain Questionnaire-2 (SF-MPQ-2): A Cross-Cultural Adaptation and Validation Study of the Persian Version in Patients with Knee Osteoarthritis

Background: We aimed to develop and validate the Persian version of Short Form McGill Pain Questionnaire-2 (SF-MPQ-2) in patients with knee osteoarthritis. Methods: Translation and back translation was performed using Beaton's guideline. After a consensus has achieved on the Persian version of SF-MPQ-2, it was administered to 30 patients with knee osteoarthritis in a pilot study. Then, we enrolled 100 patients with knee osteoarthritis to fill the final SF-MPQ-2 as well as SF-36 and WOMAC questionnaires. Forty-three patients returned 3 days after the initial visit to fill the Persian SF-MPQ-2 for the second time. Construct validity was tested by Pearson's correlation coefficient between subscales of SF-MPQ-2 and subscales of SF-36 and WOMAC. Internal consistency for total and subscales was calculated by Cronbach's alpha and reliability between test retest was performed using Intraclass correlation coefficient (ICC). Results: ICC for subscales of SF-MPQ-2 ranged from 0.73 to 0.90. The ICC for total SF-MPQ-2 was 0.90. Cronbach's alpha for subscales was 0.65-0.74 at the first visit and 0.58-0.81 at the second visit. Cronbach's alpha for the total questionnaire was 0.88 and 0.91 at the first and second visit, respectively. Pearson's correlation coefficient was highly significant when comparing subscales specifically with WOMAC (r=-0.47 to -0.61; P<0.001). Interscale correlation between subscales of SF-MPQ-2 was significant as well (r: 0.43-0.88, P<0.001). Conclusions: Persian SF-MPQ-2 showed excellent reliability and good to excellent internal consistency throughout the questionnaire. It is a valid and reliable instrument for measuring the pain intensity and applicable in osteoarthritic pain assessment.