Psychometric properties of the pain stages of change questionnaire as evaluated by rasch analysis in patients with chronic musculoskeletal pain
1 Department of Physical Medicine and Rehabilitation, Oslo University Hospital Ullevål, Pb4956 Nydalen 0429, Oslo, Norway
2 Faculty of Medicine, University of Oslo, Oslo, Norway
3 Department of Rehabilitation, University Hospital of North Norway, Tromsø, Norway
4 Faculty of Health Sciences, Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway
5 Department of Health and Care Sciences, University of Tromsø, Tromsø, Norway
BMC Musculoskeletal Disorders 2014, 15:95 doi:10.1186/1471-2474-15-95Published: 19 March 2014
Our objective was to evaluate the measurement properties of the Pain Stages of Change Questionnaire (PSOCQ) and its four subscales Precontemplation, Contemplation, Action and Maintenance.
A total of 231 patients, median age 42 years, with chronic musculoskeletal pain responded to the 30 items in PSOCQ. Thresholds for item scores, and unidimensionality and invariance of the PSOCQ and its four subscales were evaluated by Rasch analysis, partial credit model.
The items had disordered threshold and needed to be rescored. The 30 items in the PSOCQ did not fit the Rasch model Chi- square item trait statistics. All subscales fitted the Rasch models. The associations to pain (11 point numeric rating scale), emotional distress (Hopkins symptom check list v 25) and self-efficacy (Arthritis Self-Efficacy Scale) were highest for the Precontemplation subscale.
The present analysis revealed that all four subscales in PSOCQ fitted the Rasch model. No common construct for all subscales were identified, but the Action and Maintenance subscales were closely related.