Background: The main aim of this study was to compare the effectiveness of a brief intervention based on cognitive-behavioural principles (Solution Finding Approach – SFA) with the McKenzie approach (McK). A secondary aim was to determine if there were any clinical characteristics that distinguished patients who responded best to the McKenzie method.

Methods: Eligible patients who were referred by GPs to physiotherapy departments in the UK with neck or back pain were randomly allocated to McK (n= 161) or to SFA (n=154) and their outcome compared at 6 weeks, 6 and 12 months. In addition, putative predictors within the McKenzie group were compared using univariate analysis to examine the relationship between variables and outcomes. Significant variables were assessed using multiple logistic regression analyses.

Results: Both groups demonstrated modest improvements in outcomes. There were no statistically significant differences in outcomes, except 2 small but significant differences at 6 weeks. At 6 weeks, patient satisfaction was greater for McK (median 90% compared with 70% for SFA). The number of treatment successes in the McK group depended upon the definition used, but were limited. Less chronic back pain (rather than neck pain) in patients demonstrating centralisation responded best.

Conclusion: In the original RCT there were few differences between McK and SFA though modest improvements in both. In a secondary analysis of the results for the McK group there were few treatment successes according to our definition of success; these were most likely to occur in back pain patients with shorter duration symptom who demonstrated centralisation response.