title: Prognosis of patients with nonspecific neck pain: development and external validation of a prediction rule for persistence of complaints.
abstract: METHODS
  Reanalysis of data from 3 randomized controlled trials.
  
  
  OBJECTIVE
  Development and validation of a prediction rule that estimates the probability of complaints persisting for at least 6 months in patients presenting with nonspecific neck pain in primary care.
  
  
  BACKGROUND
  A substantial proportion of the neck pain patients will develop chronic neck pain. An important question is whether we can identify patients at risk of persistent complaints at the first consultation with the physician, based on their personal characteristics? A prediction model that quantifies prognosis in patients with nonspecific neck pain is not available.
  
  
  METHODS
  The study population consisted of a sample (n = 468) from the adult primary care population (18-70 years) in The Netherlands presenting with nonspecific neck pain. The primary outcome measure was global perceived recovery measured at 6 months of follow-up. Seventeen baseline characteristics of the patients were included in the analysis. Significant predictors were identified by multivariable backward stepwise logistic regression analysis. A score chart was constructed by using the regression coefficient estimates. The score chart was externally validated in a cohort of patients with nonspecific neck pain (n = 315), who participated in a randomized controlled trial in the United Kingdom (PANTHER-trial).
  
  
  RESULTS
  The multivariable analysis resulted in a set of 9 predictors. The score chart has a discriminative ability of 0.66. External validation of the score chart showed a discriminative ability of 0.65, an adequate calibration, a good fit, and a low explained variation.
  
  
  CONCLUSIONS
  We developed a score chart, estimating the probability of persistent complaints at 6 months follow-up for patients with nonspecific neck pain. This chart performed well in the study population and external validation population. The prediction which patients are more likely to develop persistent complaints is significantly improved by the score chart.
authors.affiliation: Department of General Practice, Erasmus Medical Centre, Rotterdam, The Netherlands. j.schellingerhout@erasmusmc.nl
authors.forename: Jasper M
authors.initials: JM
authors.lastname: Schellingerhout
authors.forename: Martijn W
authors.initials: MW
authors.lastname: Heymans
authors.forename: Arianne P
authors.initials: AP
authors.lastname: Verhagen
authors.forename: Martyn
authors.initials: M
authors.lastname: Lewis
authors.forename: Henrica C W
authors.initials: HC
authors.lastname: de Vet
authors.forename: Bart W
authors.initials: BW
authors.lastname: Koes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011379:Prognosis