title: Prognostic factors for recovery in chronic nonspecific low back pain: a systematic review.
abstract: BACKGROUND
  Few data are available on predictors for a favorable outcome in patients with chronic nonspecific low back pain (CNLBP).
  
  
  OBJECTIVE
  The aim of this study was to assess prognostic factors for pain intensity, disability, return to work, quality of life, and global perceived effect in patients with CNLBP at short-term (≤ 6 months) and long-term (>6 months) follow-up.
  
  
  METHODS
  Relevant studies evaluating the prognosis of CNLBP were searched in PubMed, CINAHL, and EMBASE (through March 2010). Study Selection Articles with all types of study designs were included. Inclusion criteria were: participants were patients with CNLBP (≥ 12 weeks' duration), participants were older than 18 years of age, and the study was related to prognostic factors for recovery. Fourteen studies met the inclusion criteria.
  
  
  METHODS
  Two reviewers extracted the data and details of each study.
  
  
  RESULTS
  A qualitative analysis using "level of evidence" was performed for all included studies. Data were summarized in tables and critically appraised.
  
  
  CONCLUSIONS
  The results of the studies reviewed were limited by their methodological weaknesses.
  
  
  CONCLUSIONS
  At short-term follow-up, no association was found for the factors of age and sex with the outcomes of pain intensity and disability. At long-term follow-up, smoking had the same result. At long-term follow-up, pain intensity and fear of movement had no association with disability. At short-term follow-up, conflicting evidence was found for the association between the outcomes pain intensity and disability and the factor of fear of movement. At long-term follow-up, conflicting evidence was found for the factors of age, sex, and physical job demands. At long-term follow-up, conflicting evidence also was found for the association between return to work and age, sex, and activities of daily living. At baseline, there was limited evidence of a positive influence of lower pain intensity and physical job demands on return to work. No high-quality studies were found for the outcomes of quality of life and global perceived effect.
authors.affiliation: Rotterdam University of Applied Sciences, Rotterdam, the Netherlands; Spine & Joint Centre, Rotterdam, the Netherlands; Department of General Practice, Erasmus MC, University Medical Center, Rotterdam, the Netherlands. verkerk@hr.nl
authors.forename: Karin
authors.initials: K
authors.lastname: Verkerk
authors.forename: Pim A J
authors.initials: PA
authors.lastname: Luijsterburg
authors.forename: Harard S
authors.initials: HS
authors.lastname: Miedema
authors.forename: Annelies
authors.initials: A
authors.lastname: Pool-Goudzwaard
authors.forename: Bart W
authors.initials: BW
authors.lastname: Koes
mesh_terms: D002908:Chronic Disease; D004185:Disability Evaluation; D005239:Fear; D006801:Humans; D017116:Low Back Pain / Q000523:psychology / Q000534:rehabilitation*; D010147:Pain Measurement; D011379:Prognosis; D011788:Quality of Life; D020127:Recovery of Function