Validity and responsiveness of the pain self-efficacy questionnaire in patients with neck pain disorders

Study Design Longitudinal clinimetric study. Background Pain self-efficacy predicts poor recovery, and mediates the relationship between pain and disability in patients with neck pain disorders (NPDs). The Pain Self-Efficacy Questionnaire (PSEQ) is a frequently used instrument to measure pain self-efficacy, however, its measurement properties have never been evaluated in a group of patients with NPDs. Objectives This study aimed to assess validity and responsiveness of the PSEQ in patients with NPDs. Methods Patients with NPDs (n = 161) were included. Confirmatory and exploratory factor analysis were used to assess structural validity; 12 hypotheses on expected correlations with other instruments were formulated a-priori to assess construct validity. Responsiveness was evaluated in 146 NPDs patients who underwent multimodal rehabilitation, by testing 12 hypotheses on expected effect sizes, area under the curve, and correlations with change in other instruments. Results Factor analyses showed that the PSEQ is unidimensional, whereas construct validity and responsiveness were moderate (50%-75% of hypotheses met). Validity results were consistent when analysed separately for patients with whiplash associated disorders and idiopathic neck pain, whereas responsiveness was better in patients with idiopathic neck pain. Conclusions The PSEQ is a unidimensional measure of pain self-efficacy in patients with NPDs, as found by previous studies in other populations. Nevertheless, in contrast with previous studies, its construct validity and responsiveness were found to be suboptimal in NPDs, suggesting that the content validity of the PSEQ and of the other comparator instruments used in this study should be better assessed. J Orthop Sports Phys Ther, Epub 19 Dec 2017. doi:10.2519/jospt.2018.7605.