Which Scale to Assess Pain Self-efficacy Shows Better Measurement Properties in Chronic Low Back Pain? A Head-To-Head Comparison Study.

OBJECTIVE

To compare the quality of the measurement properties of Pain Self-Efficacy Questionnaire (PSEQ)-10, PSEQ-4, PSEQ-2, Chronic Pain Self-Efficacy Scale (CPSS) long-form, and CPSS short-form (CPSS-SF) in patients with chronic low back pain (CLBP).

DESIGN

Cross-sectional and longitudinal studies (measurement properties).

SETTING

Outpatient rehabilitation.

PARTICIPANTS

Participants (N=245) with nonspecific CLBP (18-60y, 63% women) were enrolled in this study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Pain self-efficacy questionnaires were administered on 3 occasions: baseline assessment, 1 week after the first assessment (reliability), and after an 8-week exercise program (responsiveness). The intraclass correlation coefficient (ICC) and Cronbach α were used to assess reliability and internal consistency, respectively. Pearson correlation and confirmatory factor analyses were used to assess construct validity. The area under the curve and hypothesis testing were used to assess responsiveness.

RESULTS

No difference was observed for all the questionnaires regarding internal consistency (Cronbach α>.7), criterion validity (r>.88), and reliability (ICC>.7). The scales confirmed >75% of the hypotheses for the construct validity, except for CPSS-SF. PSEQ-2 did not meet the criterion for structural validity. PSEQ-10 met all the criteria for good measurement properties according to Consensus-Based Standards for the Selection of Health Measurement Instruments.

CONCLUSIONS

It was not possible to calculate structural validity for PSEQ-2, CPSS-SF did not meet the criterion for suitable hypothesis testing for construct validity, and all the questionnaires did not show suitable measurement error, except for the PSEQ-10. Hence, the PSEQ-10 was the unique scale that met all the criteria for good measurement properties for assessing pain self-efficacy in CLBP.