title: Predictors of improvement in patients with acute and chronic low back pain undergoing chiropractic treatment.
abstract: OBJECTIVE
  The purpose of this study was to investigate outcomes and prognostic factors in patients with acute or chronic low back pain (LBP) undergoing chiropractic treatment.
  
  
  METHODS
  This was a prognostic cohort study with medium-term outcomes. Adult patients with LBP of any duration who had not received chiropractic or manual therapy in the prior 3 months were recruited from multiple chiropractic practices in Switzerland. Participating doctors of chiropractic were allowed to use their typical treatment methods (such as chiropractic manipulation, soft tissue mobilization, or other methods) because the purpose of the study was to evaluate outcomes from routine chiropractic practice. Patients completed a numerical pain rating scale and Oswestry disability questionnaire immediately before treatment and at 1 week, 1 month, and 3 months after the start of treatment, together with self-reported improvement using the Patient Global Impression of Change.
  
  
  RESULTS
  Patients with acute (<4 weeks; n = 523) and chronic (>3 months; n = 293) LBP were included. Baseline mean pain and disability scores were significantly (P < .001) higher in patients with acute LBP. In both groups of patients, there were significant (P < .0001) improvements in mean scores of pain and disability at 1 week, 1 month, and 3 months, although these change scores were significantly greater in the acute group. Similarly, a greater proportion of patients in the acute group reported improvement at each follow-up. The most consistent predictor was self-reported improvement at 1 week, which was independently associated with improvement at 1 month (adjusted odds ratio [OR], 2.4 [95% confidence interval, 1.3-4.5] and 5.0 [2.4-10.6]) and at 3 months (2.9 [1.3-6.6] and 3.3 [1.3-8.7]) in patients with acute and chronic pain, respectively. The presence of radiculopathy at baseline was not a predictor of outcome.
  
  
  CONCLUSIONS
  Patients with chronic and acute pain reporting that they were "much better" or "better" on the Patient Global Impression of Change scale at 1 week after the first chiropractic visit were 4 to 5 times more likely to be improved at both 1 and 3 months compared with patients who were not improved at 1 week. Patients with acute pain reported more severe pain and disability initially but recovered faster. Patients with chronic and acute back pain both reported good outcomes, and most patients with radiculopathy also improved.
authors.affiliation: Chiropractic Department, Faculty of Medicine, University of Zürich, Zürich, Switzerland. Cynthia.peterson@balgrist.ch
authors.forename: Cynthia K
authors.initials: CK
authors.lastname: Peterson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Bolton
authors.forename: B Kim
authors.initials: BK
authors.lastname: Humphreys
mesh_terms: D059787:Acute Pain / Q000628:therapy*; D000328:Adult; D059350:Chronic Pain / Q000628:therapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000628:therapy*; D008297:Male; D026882:Manipulation, Chiropractic; D008875:Middle Aged; D011379:Prognosis; D016896:Treatment Outcome