Predictive factors for disability outcome at twenty weeks and two years following a pain self-management group intervention in patients with persistent neck pain in primary health care.

OBJECTIVE To explore possible predictors associated with short-term (post-treatment) and long-term (2 years) treatment success in terms of pain-related disability for patients with persistent neck pain following a pain and stress self-management intervention (PASS). METHODS Data from 77 participants assigned to PASS in a randomized controlled trial were explored to identify possible predictors of favourable outcome regarding pain-related disability as measured by the Neck Disability Index (NDI), by use of Pearson correlation analysis, partial least squares (PLS) and ordinary least squares (OLS) regression analyses. Data from self-assessment questionnaires completed by the participants before, post-treatment (i.e. 20 weeks after inclusion) and 2 years after inclusion in the study, were used. RESULTS Multivariate PLS regression analysis showed that baseline scores in NDI, the Self-Efficacy Scale (SES) and pain intensity explained 31% of the variance in disability (NDI) post-treatment. Multivariate PLS regression analysis showed that post-treatment scores in NDI, SES and pain intensity explained 68% of the variance in disability (NDI) at 2 years. CONCLUSION Treatment gains, as measured by post-treatment scores at 20-week follow-up, in disability, self-efficacy and pain intensity were associated with long-term outcome in pain-related disability at 2 years, in patients with persistent neck pain participating in a self-management group intervention in primary health care.