title: Development and validation of a clinical prediction rule for chest wall syndrome in primary care.
abstract: BACKGROUND
  Chest wall syndrome (CWS), the main cause of chest pain in primary care practice, is most often an exclusion diagnosis. We developed and evaluated a clinical prediction rule for CWS.
  
  
  METHODS
  Data from a multicenter clinical cohort of consecutive primary care patients with chest pain were used (59 general practitioners, 672 patients). A final diagnosis was determined after 12 months of follow-up. We used the literature and bivariate analyses to identify candidate predictors, and multivariate logistic regression was used to develop a clinical prediction rule for CWS. We used data from a German cohort (n = 1212) for external validation.
  
  
  RESULTS
  From bivariate analyses, we identified six variables characterizing CWS: thoracic pain (neither retrosternal nor oppressive), stabbing, well localized pain, no history of coronary heart disease, absence of general practitioner's concern, and pain reproducible by palpation. This last variable accounted for 2 points in the clinical prediction rule, the others for 1 point each; the total score ranged from 0 to 7 points. The area under the receiver operating characteristic (ROC) curve was 0.80 (95% confidence interval 0.76-0.83) in the derivation cohort (specificity: 89%; sensitivity: 45%; cut-off set at 6 points). Among all patients presenting CWS (n = 284), 71% (n = 201) had a pain reproducible by palpation and 45% (n = 127) were correctly diagnosed. For a subset (n = 43) of these correctly classified CWS patients, 65 additional investigations (30 electrocardiograms, 16 thoracic radiographies, 10 laboratory tests, eight specialist referrals, one thoracic computed tomography) had been performed to achieve diagnosis. False positives (n = 41) included three patients with stable angina (1.8% of all positives). External validation revealed the ROC curve to be 0.76 (95% confidence interval 0.73-0.79) with a sensitivity of 22% and a specificity of 93%.
  
  
  CONCLUSIONS
  This CWS score offers a useful complement to the usual CWS exclusion diagnosing process. Indeed, for the 127 patients presenting CWS and correctly classified by our clinical prediction rule, 65 additional tests and exams could have been avoided. However, the reproduction of chest pain by palpation, the most important characteristic to diagnose CWS, is not pathognomonic.
authors.affiliation: Institute of General Medicine, University of Lausanne, Lausanne, Switzerland. alexandre@ronga.net
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ronga
authors.forename: Paul
authors.initials: P
authors.lastname: Vaucher
authors.forename: Jörg
authors.initials: J
authors.lastname: Haasenritter
authors.forename: Norbert
authors.initials: N
authors.lastname: Donner-Banzhoff
authors.forename: Stefan
authors.initials: S
authors.lastname: Bösner
authors.forename: François
authors.initials: F
authors.lastname: Verdon
authors.forename: Thomas
authors.initials: T
authors.lastname: Bischoff
authors.forename: Bernard
authors.initials: B
authors.lastname: Burnand
authors.forename: Bernard
authors.initials: B
authors.lastname: Favrat
authors.forename: Lilli
authors.initials: L
authors.lastname: Herzig
mesh_terms: D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000209:etiology*; D015331:Cohort Studies; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000379:methods*; D012372:ROC Curve; D035441:Thoracic Wall / Q000503:physiopathology*