OBJECTIVES:
To assess overall responses to treatments among non-specific low back pain (NSLBP) patients in clinical trials to examine the pattern following a wide range of treatments.
METHODS:
We conducted a systematic review of published trials on NSLBP and meta-analysis of within-group responses to treatments calculated as the standardized mean difference (SMD). We included randomized controlled trials that investigated the effectiveness of primary care treatments in NSLBP patients agedā„18 years. Outcome measures included the visual analogue scale for pain severity, Roland Morris Disability Questionnaire and Oswestry Disability Index for physical functioning.
RESULTS:
One hundred and eighteen trials investigating a wide range of primary care treatment for NSLBP were included. Plots of response to treatments showed that there was a similar pattern of initial improvement at 6 weeks followed by smaller improvement for both pain and functional disability at long-term follow-up. This was also shown by the pooled SMD for pain which was 0.86 (95% CI 0.65, 1.07) at 6 weeks, 1.07 (95% CI 0.87, 1.27) at 13 weeks, 1.03 (95% CI 0.82, 1.25) at 27 weeks and 0.88 (95% CI 0.60, 1.1) at 52 weeks. There was a wide heterogeneity in the size of improvement. This heterogeneity, however, was not explained by differences in the type of treatment classified as active, placebo, usual care or waiting list controls or as pharmacological or non-pharmacological treatment.
CONCLUSIONS:
NSLBP symptoms seem to improve in a similar pattern in clinical trials following a wide variety of active as well as inactive treatments. It is important to explore factors other than the treatment, that might influence symptom improvement.