title: Clinical decision rule for primary care patient with acute low back pain at risk of developing chronic pain.
abstract: BACKGROUND
  Primary care clinicians need to identify candidates for early interventions to prevent patients with acute pain from developing chronic pain.
  
  
  OBJECTIVE
  We conducted a 2-year prospective cohort study of risk factors for the progression to chronic pain and developed and internally validated a clinical decision rule (CDR) that stratifies patients into low-, medium-, and high-risk groups for chronic pain.
  
  
  METHODS
  This is a prospective cohort study in primary care.
  
  
  METHODS
  Patients with acute low back pain (LBP, ≤30 days duration) were included.
  
  
  METHODS
  Outcome measures were self-reported perceived nonrecovery and chronic pain.
  
  
  METHODS
  Patients were surveyed at baseline, 6 months, and 2 years. We conducted bivariate and multivariate regression analyses of demographic, clinical, and psychosocial variables for chronic pain outcomes, developed a CDR, and assessed its performance by calculating the bootstrapped areas under the receiver-operating characteristic curve (AUC) and likelihood ratios.
  
  
  RESULTS
  Six hundred five patients enrolled: 13% had chronic pain at 6 months and 19% at 2 years. An eight-item CDR was most parsimonious for classifying patients into three risk levels. Bootstrapped AUC was 0.76 (0.70-0.82) for the 6-month CDR. Each 10-point score increase (60-point range) was associated with an odds ratio of 11.1 (10.8-11.4) for developing chronic pain. Using a less than 5% probability of chronic pain as the cutoff for low risk and a greater than 40% probability for high risk, likelihood ratios were 0.26 (0.14-0.48) and 4.4 (3.0-6.3) for these groups, respectively.
  
  
  CONCLUSIONS
  A CDR was developed that may help primary care clinicians classify patients with strictly defined acute LBP into low-, moderate-, and high-risk groups for developing chronic pain and performed acceptably in 1,000 bootstrapped replications. Validation in a separate sample is needed.
authors.affiliation: Department of Family Medicine, University of California-San Francisco, 1545 Divisadero St, San Francisco, CA 94115, USA; Osher Center for Integrative Medicine, University of California-San Francisco, 1545 Divisadero St, 4th Floor, San Francisco, CA 94115, USA. Electronic address: mehlingw@ocim.ucsf.edu.
authors.forename: Wolf E
authors.initials: WE
authors.lastname: Mehling
authors.affiliation: Department of Epidemiology and Biostatistics, University of Georgia, 101 Buck Rd, Athens, GA 30602, USA.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Ebell
authors.affiliation: Department of Medicine, University of California-San Francisco, 1545 Divisadero St, San Francisco, CA 94115, USA; Division of Research, Kaiser Permanente, Northern California, 2000 Broadway, Oakland, CA 94612, USA.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Avins
authors.affiliation: Osher Center for Integrative Medicine, University of California-San Francisco, 1545 Divisadero St, 4th Floor, San Francisco, CA 94115, USA; Department of Medicine, University of California-San Francisco, 1545 Divisadero St, San Francisco, CA 94115, USA.
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Hecht
mesh_terms: D059787:Acute Pain / Q000473:pathology* / Q000523:psychology; D000293:Adolescent; D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000473:pathology* / Q000523:psychology; D000066491:Clinical Decision-Making; D020000:Decision Support Systems, Clinical; D018450:Disease Progression; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000473:pathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011320:Primary Health Care; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
keywords: Acute pain; Chronic pain; Clinical decision rule; Low back pain; Prediction; Primary care