Validation of pain catastrophizing Scale-Thai version in older adults with knee osteoarthritis

Abstract

Pain catastrophizing is an important psychological factor influencing pain severity and disability in knee osteoarthritis, one of the most common musculoskeletal problems in older adults. The Pain Catastrophizing Scale was developed in English to measure how catastrophizing impacts on pain experience but to date, no Thai version has been validated. The purpose of this study was to translate and examine psychometric properties of the Pain Catastrophizing Scale-Thai Version in older adults with knee osteoarthritis. This study included two phases. Phase 1 consisted of translating the instruments into Thai using the committee approach; conducting interviews to confirm their accuracy; and assessing content validity by expert committee. Phase 2 consisted of testing construct validity using convergent and divergent validities, and exploratory factor analysis; and examining internal consistency reliability. A convenience sample of 150 older adults with knee osteoarthritis was asked to complete the Numeric Rating Scale, the Arthritis Impact Measurement Scales 2-Short Form, and the Pain Catastrophizing Scale-Thai Version. The content validity index for item and scale level index confirmed its validity. Factor analysis indicated three factors, rumination, magnification, and helplessness, accounted for 65.97%of variance and were positively associated with pain intensity level and negatively associated with health status. Cronbach's alpha coefficients for the total score and subscales were at an acceptable level. We conclude that the Pain Catastrophizing Scale-Thai version is a valid and reliable instrument able to be use for clinical or research purposes but encourage further testing with different samples by nurse researchers and others in different communities.