title: Impact of clinical trial findings on Bell's palsy management in general practice in the UK 2001-2012: interrupted time series regression analysis.
abstract: OBJECTIVE
  To measure the incidence of Bell's palsy and determine the impact of clinical trial findings on Bell's palsy management in the UK.
  
  
  METHODS
  Interrupted time series regression analysis and incidence measures.
  
  
  METHODS
  General practices in the UK contributing to the Clinical Practice Research Datalink (CPRD).
  
  
  METHODS
  Patients ≥16 years with a diagnosis of Bell's palsy between 2001 and 2012.
  
  
  METHODS
  (1) Publication of the 2004 Cochrane reviews of clinical trials on corticosteroids and antivirals for Bell's palsy, which made no clear recommendation on their use and (2) publication of the 2007 Scottish Bell's Palsy Study (SBPS), which made a clear recommendation that treatment with prednisolone alone improves chances for complete recovery.
  
  
  METHODS
  Incidence of Bell's palsy per 100 000 person-years. Changes in the management of Bell's palsy with either prednisolone therapy, antiviral therapy, combination therapy (prednisolone with antiviral therapy) or untreated cases.
  
  
  RESULTS
  During the 12-year period, 14 460 cases of Bell's palsy were identified with an overall incidence of 37.7/100 000 person-years. The 2004 Cochrane reviews were associated with immediate falls in prednisolone therapy (-6.3% (-11.0 to -1.6)), rising trends in combination therapy (1.1% per quarter (0.5 to 1.7)) and falling trends for untreated cases (-0.8% per quarter (-1.4 to -0.3)). SBPS was associated with immediate increases in prednisolone therapy (5.1% (0.9 to 9.3)) and rising trends in prednisolone therapy (0.7% per quarter (0.4 to 1.2)); falling trends in combination therapy (-1.7% per quarter (-2.2 to -1.3)); and rising trends for untreated cases (1.2% per quarter (0.8 to 1.6)). Despite improvements, 44% still remain untreated.
  
  
  CONCLUSIONS
  SBPS was clearly associated with change in management, but a significant proportion of patients failed to receive effective treatment, which cannot be fully explained. Clarity and uncertainty in clinical trial recommendations may change clinical practice. However, better ways are needed to understand and circumvent barriers in implementing clinical trial findings.
authors.affiliation: Division of Population Health Sciences, Medical Research Institute, University of Dundee, Dundee, UK.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Morales
authors.forename: Peter T
authors.initials: PT
authors.lastname: Donnan
authors.forename: Fergus
authors.initials: F
authors.lastname: Daly
authors.forename: Tjeerd Van
authors.initials: TV
authors.lastname: Staa
authors.forename: Frank M
authors.initials: FM
authors.lastname: Sullivan
keywords: Clinical trials < Therapeutics; Epidemiology; Primary Care