title: Using an electronic medical record (EMR) to conduct clinical trials: Salford Lung Study feasibility.
abstract: BACKGROUND
  Real-world data on the benefit/risk profile of medicines is needed, particularly in patients who are ineligible for randomised controlled trials conducted for registration purposes. This paper describes the methodology and source data verification which enables the conduct of pre-licensing clinical trials of COPD and asthma in the community using the electronic medical record (EMR), NorthWest EHealth linked database (NWEH-LDB) and alert systems.
  
  
  METHODS
  Dual verification of extracts into NWEH-LDB was performed using two independent data sources (Salford Integrated Record [SIR] and Apollo database) from one primary care practice in Salford (N = 3504). A feasibility study was conducted to test the reliability of the NWEH-LDB to support longitudinal data analysis and pragmatic clinical trials in asthma and COPD. This involved a retrospective extraction of data from all registered practices in Salford to identify a cohort of patients with a diagnosis of asthma (aged ≥18) and/or COPD (aged ≥40) and ≥2 prescriptions for inhaled bronchodilators during 2008. Health care resource utilisation (HRU) outcomes during 2009 were assessed. Exacerbations were defined as: prescription for oral corticosteroids (OCS) in asthma and prescription of OCS or antibiotics in COPD; and/or hospitalisation for a respiratory cause.
  
  
  RESULTS
  Dual verification demonstrated consistency between SIR and Apollo data sources: 3453 (98.6%) patients were common to both systems; 99.9% of prescription records were matched and of 29,830 diagnosis records, one record was missing from Apollo and 272 (0.9%) from SIR. Identified COPD patients were also highly concordant (Kappa coefficient = 0.98). A total of 7981 asthma patients and 4478 COPD patients were identified within the NWEH-LDB. Cohort analyses enumerated the most commonly prescribed respiratory medication classes to be: inhaled corticosteroids (ICS) (42%) and ICS plus long-acting β2-agonist (LABA) (40%) in asthma; ICS plus LABA (55%) and long-acting muscarinic antagonists (36%) in COPD. During 2009 HRU was greater in the COPD versus asthma cohorts, and exacerbation rates in 2009 were higher in patients who had ≥2 exacerbations versus ≤1 exacerbation in 2008 for both asthma (137.5 vs. 20.3 per 100 person-years, respectively) and COPD (144.6 vs. 41.0, respectively).
  
  
  CONCLUSIONS
  Apollo and SIR data extracts into NWEH-LDB showed a high level of concordance for asthma and COPD patients. Longitudinal data analysis characterized the COPD and asthma populations in Salford including medications prescribed and health care utilisation outcomes suitable for clinical trial planning.
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK. Hanaa.Elkhenini@srft.nhs.uk.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK. Hanaa.Elkhenini@srft.nhs.uk.
authors.forename: Hanaa F
authors.initials: HF
authors.lastname: Elkhenini
authors.affiliation: GlaxoSmithKline R&D, Worldwide Epidemiology, Wavre, Belgium.|GlaxoSmithKline R&D, Worldwide Epidemiology, Uxbridge, UK.
authors.forename: Kourtney J
authors.initials: KJ
authors.lastname: Davis
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: Norman D
authors.initials: ND
authors.lastname: Stein
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: John P
authors.initials: JP
authors.lastname: New
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Delderfield
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Gibson
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|University Hospital South Manchester, Manchester, UK.
authors.forename: Jorgen
authors.initials: J
authors.lastname: Vestbo
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|University Hospital South Manchester, Manchester, UK.
authors.forename: Ashley
authors.initials: A
authors.lastname: Woodcock
authors.affiliation: Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.|NorthWest EHealth, Salford Royal NHS Foundation Trust, Salford, UK.
authors.forename: Nawar Diar
authors.initials: ND
authors.lastname: Bakerly
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy / Q000453:epidemiology; D002986:Clinical Trials as Topic / Q000379:methods*; D016208:Databases, Factual / Q000706:statistics & numerical data*; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005240:Feasibility Studies; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000453:epidemiology