Can we identify people at risk of non-recovery after acute occupational low back pain? Results of a review and higher-order analysis.

Purpose: To identify prognostic factors in the literature that may predict a poor recovery from acute occupational low back pain (LBP).

Methods: Four international databases (Medline, CINAHL, EMBASE, and PsycINFO) were reviewed, searching all articles indexed up to November 2007 with the term low back pain combined with the terms prognostic, prospective, or cohort. Following application of inclusion criteria, 10 articles were found to be appropriate for data extraction. Each article was critically appraised by two independent reviewers. Statistical pooling was performed on any factor evaluated in at least three independent cohorts.

Results: Seven cohorts were identified, with a total sample size of 2,484 subjects. Only three factors were followed in at least three cohorts and were therefore suitable for statistical pooling: female gender (OR=1.28, 95% CI: 1.03-1.58); pain radiation (OR=1.37, 95% CI: 0.79-2.39); and previous history of back pain (OR=0.91, 95% CI: 0.52-1.60). There was significant heterogeneity within the female gender factor; compensation of subjects for study participation appeared to moderate its effect.

Conclusion: After statistical pooling, only female gender achieved statistical significance as a prognostic factor for prolonged recovery. Further research is necessary to determine prognostic factors for non-recovery in acute LBP.