Psychometric evaluation of the Danish version of the Pain Self-Efficacy Questionnaire in patients with subacute and chronic low back pain.

Objective: The Pain Self-Efficacy Questionnaire (PSEQ) is a widely used patient-reported outcome measure designed to assess the level of pain self-efficacy in patients with low back pain (LBP). Although the PSEQ has been translated into Danish, its measurement properties remain unknown in patients with subacute and chronic LBP in Danish outpatient clinics. The aim of this study was to investigate the construct validity, internal consistency, test-retest reliability, and measurement error of the Danish version of the PSEQ in a group of Danish patients with subacute and chronic LBP in a hospital outpatient setting.

Methods: Patients with LBP referred to two Danish outpatient clinics were recruited for this study. Two days after the consultation, the participants were emailed a link to a survey that included the following outcome measures: the PSEQ, the Oswestry Disability Index, the Numeric Pain Rating Scale, and the Tampa Scale of Kinesiophobia. Five days after completion of the survey, a new survey that included the PSEQ was sent to the participants.

Results: In total, 109 participants were included for the analysis of construct validity and internal consistency, with 94 participants included for the analysis of test-retest reliability and measurement error. Construct validity was found to be high and internal consistency was acceptable, with Cronbach's alpha = 0.93 (95% confidence interval [CI] = 0.91-0.93). Test-retest reliability was found to be good, with an intraclass correlation coefficient (ICC_2.1) of 0.89 (95% CI = 0.82-0.92). The standard error of measurement was calculated to be 4.52 and the smallest detectable change was 12.5 points.

Conclusions: The Danish version of the PSEQ showed acceptable measurement properties in terms of construct validity, internal consistency, and test-retest reliability in a group of patients with subacute and chronic LBP. However, further studies are needed to investigate other aspects of the measurement properties.