Prognostic factors for improved physical and emotional functioning one year after interdisciplinary rehabilitation in patients with chronic pain: Results from a national quality registry in Sweden.

OBJECTIVE: To investigate prognostic factors for physical and emotional functioning following interdisciplinary multimodal pain rehabilitation, by targeting patients' baseline characteristics and health measures.
METHODS: A prospective cohort of 2,876 patients from 38 specialist clinics across Sweden, who were completing interdisciplinary multimodal pain rehabilitation programmes, was followed through the Swedish Quality Registry for Pain Rehabilitation, from initial assessment to 12-month follow-up. Using logistic regression, baseline data were regressed to predict improvement in Physical functioning and Emotional functioning, fused by principal component analyses using the 36-item Short Form Health Survey (SF-36) and the Hospital Anxiety and Depression Scale (HADS).
RESULTS: Employment status emerged as having the largest effect sizes in both Physical functioning and Emotional functioning; Working: odds ratio (OR) 2.05 (95% confidence interval (95% CI) 1.64-2.56) and OR 1.59 (95% CI 1.27-1.98), respectively. Strong beliefs in restored health, better initial emotional health, lower levels of pain and pain interference, and younger age all predicted Physical functioning. European origin, higher levels of general activity, and sense of life control all predicted Emotional functioning. Worse initial physical and emotional health predicted the corresponding dependent outcomes.
CONCLUSION: Employment was consistently found to be an important prognostic factor, suggesting the significance of avoiding delay in interdisciplinary multimodal pain rehabilitation. A positive treatment expectancy was of importance. In general, multidimensional measures indicated that better initial status was more favourable; however, inconsistency implies a complex prognostic picture.