title: Identifying general practice patients diagnosed with asthma and their exacerbation episodes from prescribing data.
abstract: OBJECTIVE
  To determine the reliability of identifying patients diagnosed with asthma in general practice and their asthma exacerbation episodes from prescribing data.
  
  
  METHODS
  Automated database from 17 general practitioners (29,805 patients) in the northern Netherlands.
  
  
  METHODS
  Sensitivity, specificity and predictive values of four criteria for identifying patients diagnosed with asthma and two criteria for identifying asthma exacerbation episodes were calculated using the registered diagnosis as gold standard.
  
  
  RESULTS
  Prescription of one or more anti-asthma medications identified 95% of patients with an asthma diagnosis (positive predictive value 0.70), while two or more anti-asthma medications identified 71% (positive predictive value 0.79). A combination of oral corticosteroids or antibiotics identified 55% of exacerbations.
  
  
  CONCLUSIONS
  Asthma patients can be identified reliably from prescribing data, but identification of asthma exacerbations was poor. The preference for one criterion over another for identifying patients diagnosed with asthma will depend on the reason for patient selection.
authors.affiliation: Groningen University Institute of Drug Exploration (GUIDE), Clinical Pharmacology, University of Groningen, The Netherlands. L.Pont@med.rug.nl
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Pont
authors.forename: G Th
authors.initials: GT
authors.lastname: van der Werf
authors.forename: P
authors.initials: P
authors.lastname: Denig
authors.forename: F M
authors.initials: FM
authors.lastname: Haaijer-Ruskamp
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001249:Asthma / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology*; D016208:Databases, Factual; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D015203:Reproducibility of Results
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D000900:Anti-Bacterial Agents