Group cognitive behavioural treatment for low-back pain in primary care : a randomised controlled trial and cost-effectiveness analysis

Background Low-back pain is a common and costly problem. We estimated the effectiveness of a group cognitive behavioural intervention in addition to best practice advice in people with low-back pain in primary care. Methods In this pragmatic, multicentre, randomised controlled trial with parallel cost-effectiveness analysis undertaken in England, 701 adults with troublesome subacute or chronic low-back pain were recruited from 56 general practices and received an active management advisory consultation. Participants were randomly assigned by computer-generated block randomisation to receive an additional assessment and up to six sessions of a group cognitive behavioural intervention (n=468) or no further intervention (control; n=233). Primary outcomes were the change from baseline in Roland Morris disability questionnaire and modified Von Korff scores at 12 months. Assessment of outcomes was blinded and Wowed the intention-to-treat principle, including all randomised participants who provided follow-up data. This study is registered, number ISRCTN54717854. Findings 399 (85%) participants in the cognitive behavioural intervention group and 199 (85%) participants in the control group were included in the primary analysis at 12 months. The most frequent reason for participant withdrawal was unwillingness to complete questionnaires. At 12 months, mean change from baseline in the Roland Morris questionnaire score was 1.1 points (95% CI 0.39-1.72) in the control group and 2.4 points (1.89-2.84) in the cognitive behavioural intervention group (difference between groups 1.3 points, 0.56=2.06; p=0.0008). The modified Von Korff disability score changed by 5.4% (1.99-8.90) and 13.8% (11.39-16.28), respectively (difference between groups 8.4%, 4.47-12.32; p<0.0001). The modified Von Korff pain score changed by 6.4% (3.14-9.66) and 13.4% (10.77-15.96), respectively (difference between groups 7.0%, 3.12-10.81; p