Critical Literature Review of Systematic Reviews on Chronic Low Back Pain

Article type
Year
Authors
Furlan A, Esmail R, Clarice J, Irvin E, Sinclair S, Bombardier C
Abstract
Introduction:

Objectives: To identify systematic reviews and meta-analyses of therapies for chronic non-specific low back pain and to critically appraise them.

Methods: Literature searches of MEDLINE, EMBASE, Psycinfo and the Cochrane Library were conducted. Other sources were also investigated such as: contacts with experts in the field and with the Pain Relief Group database and also the references listed in the retrieved articles. Titles and abstracts were reviewed by 2 authors (RE and JC) using 3 inclusion criteria: 1) chronic low back pain, 2) systematic literature review and 3) addresses a treatment intervention. Articles were retrieved and the same criteria were applied under blinded conditions. Data were extracted from each systematic review by 3 authors (RE, JC and AF).

Results: The search strategy retrieved 1102 titles and abstracts of which 109 met inclusion criteria. A review of the full original 109 articles excluded an additional 72 articles. Data abstraction and methodological assessment were conducted on 37 articles. The most common intervention studied was spinal manipulation/mobilization in 7 reviews followed by acupuncture in 4 and antidepressant drugs in 4. In 5 articles the authors studied more than one intervention (mixed group). The average quality score of all reviews was 4.1 according to a validated methodological quality assessment instrument which ranges from 1 (low quality) to 7 (high quality). The reviews were published between 1989 and 1999. Although there is a trend for recent reviews to be of higher quality (coef. correlation=0.26) this difference is not statistically significant (p=0.12). There were 19 narrative reviews and 18 meta-analyses. The narrative reviews achieved higher scores (4.8) compared with meta-analyses (3.5), this difference is statistically significant (p=0.035). Fifty-six percent of the reviews had positive results but they had lower quality scores (3.4) compared with those that had negative or uncertain conclusions which had higher quality scores (4.6), this difference is statistically significant (p=0.045).

Discussion: The overall quality of systematic reviews for chronic low back pain is satisfactory. There is a tendency for more recent reviews to be of better quality. Surprisingly narrative reviews were rated of higher quality than meta-analyses. Systematic reviews with negative or uncertain conclusions had higher quality scores compared to those with positive conclusions. This findings underscores the large number of low quality trials published in the field of chronic low back pain.