The natural history of back pain after a randomised controlled trial of acupuncture vs usual care--long term outcomes.

INTRODUCTION

There is growing evidence about the effectiveness of acupuncture in the short term treatment of chronic low back pain but little is known about long term outcomes. To address this question we followed up participants of a past randomised controlled trial of acupuncture to assess outcomes after 5.5 to 7 years.

METHODS

A postal questionnaire assessing pain, quality of life, disability, experience with back pain and healthcare resource use was sent to all 239 participants of the York Acupuncture for Back Pain trial.

RESULTS

Response to the survey was low at 43.9%. Pain measured by the SF-36 Bodily Pain dimension was maintained in the acupuncture group since the last follow up 3.5 to 5 years previously. The usual care group had improved over the intervening years and there was now no evidence of a difference between the groups (difference -0.4 points, 95% confidence interval -10.1 to 9.7). The results were unchanged on sensitivity analysis using multiple imputation. In both groups back pain had not completely resolved and worry about back health was moderate. Physiotherapy and acupuncture were used at similar rates for continuing treatment.

DISCUSSION

We theorise that exposure to a short course of acupuncture speeds natural recovery from a back pain episode, but improvements plateau after two years. Acupuncture is often accessed privately for long term management of back pain but is rarely available within the health service. While our study methods were robust, the low response rate means that our findings should be interpreted with caution.