Patients selected to participate in multimodal pain rehabilitation programmes in primary care-a multivariate cross-sectional study focusing on gender and sick leave.

Background and aims A multimodal rehabilitation programme (MMRP) is an evidence-based treatment of chronic pain conditions. The complexity involved in chronic pain needs to be identified and evaluated in order to adapt the rehabilitation to patients' needs. The aim was to investigate the multivariate relationships between self-reported variables in patients with chronic pain before taking part in MMRP in primary care, with a special focus on gender and degree of sick leave. Methods Prior to MMRP, 397 patients (339 women and 58 men) filled in a questionnaire about pain, healthcare aspects, health-related quality of life, anxiety and depression, coping, physical function, and work-related variables e.g. sick leave. Data were analysed by principal component analysis (PCA) and partial least square analysis. Results The PCA identified four components that explained 47% of the variation in the investigated data set. The first component showed the largest variation and was primarily explained by anxiety and depression, quality of life, acceptance (activity engagement), and pain-related disability. Gender differences were only seen in one component with the pain variables having the highest loadings. Degree of sick leave was not well explained by the variables in the questionnaire. Conclusions The questionnaire filled out by the patients prior to participation in MMRP in primary care identified much of the complexity of chronic pain conditions but there is room for improvement, e.g. regarding explanation of work-related factors. In the multivariate analysis, gender did not fall out as an important factor for how most patients answered the questions. Implications There are not many studies that describe patients who undergo MMRP in primary care since previously such patients were treated mostly in specialist care. More knowledge is needed about these patients in order to improve rehabilitation plans and interventions. The results suggest that the questionnaire identifies the complexity among chronic pain patients in primary care. The identified components could improve assessment before MMRP and contribute to better tailored programmes.