Reliability and smallest detectable change of the Danish version of the Pain Self-Efficacy Questionnaire in patients with chronic low back pain

Objectives: Low back pain (LBP) is the leading cause of disability and a global public health concern. Studies indicate that pain self-efficacy is associated with the development of disability in chronic LBP (CLBP) patients. The Pain Self-Efficacy Questionnaire (PSEQ) is a commonly used questionnaire to assess pain self-efficacy in patients with CLBP. It is essential to examine the psychometric properties of the PSEQ in the population in which it is to be used. Thus, the aim of this study is to evaluate the reliability and smallest detectable change of the Danish version of the Pain Self-Efficacy Questionnaire (PSEQ-DK) in patients with CLBP before implementing it as an outcome measure in an inpatient rehabilitation context. Methods: This observational study including 92 patients with CLBP was conducted in a multidisciplinary rehabilitation facility in Denmark. The psychometric properties statistically tested included reliability, smallest detectable change and floor and ceiling effect of the PSEQ-DK. Results: The reliability analysis included 92 patients and revealed an weighted kappa of 0.82 (95% Cl 0.75; 0.88) and Intraclass correlation coefficient of 0.83 (95% CI 0.75; 0.88), which corresponds to a good reliability. The smallest detectable change was 12.67. Conclusions: The present study demonstrated that the PSEQ-DK had a good reliability in patients with CLBP in an inpatient rehabilitation context. The current results expand our knowledge of the reliability and smallest detectable change of the PSEQ-DK. In order to implement PSEQ-DK in a rehabilitation context for evaluative purposes future studies should focus on examining responsiveness and interpretability.