Pain belief screening instrument: Development and preliminary validation of a screening instrument for disabling persistent pain.

OBJECTIVE To develop and test the ability of a screening instrument to identify subgroups among primary healthcare patients with musculoskeletal pain. The Pain Belief Screening Instrument covers pain intensity, disability, self-efficacy, fear avoidance and catastrophizing. DESIGN Cross-sectional, correlational and comparative study. SUBJECTS Patients in primary healthcare (n1 = 215; n2 = 93) with a pain duration of 4 weeks or more were included. METHODS Items for the Pain Belief Screening Instrument were derived from principal component analyses of: the Self-efficacy Scale, the Tampa Scale of Kinesiophobia and the Catastrophizing subscale in the Coping Strategies Questionnaire. Cluster solutions of scores on the screening instrument and the original instruments were cross-tabulated. The reliability of items in the Pain Belief Screening Instrument was examined. RESULTS The screening instrument identified 2 groups: high- or low-risk profile for pain-related disability. Validity was in-between moderate and substantial (kappa = 0.61, p < 0.001). The reliability of each item in the Pain Belief Screening Instrument in relation to the corresponding item in the original instruments was moderate to high (rs 0.50-0.80, p < 0.01). CONCLUSION The screening instrument fairly well replicated subgroups identified by the original instruments. The reliability of items in the screening instrument was acceptable. Further testing of predictive validity for a primary healthcare population is needed..