title: Validation of the Recording of Acute Exacerbations of COPD in UK Primary Care Electronic Healthcare Records.
abstract: BACKGROUND
  Acute Exacerbations of COPD (AECOPD) identified from electronic healthcare records (EHR) are important for research, public health and to inform healthcare utilisation and service provision. However, there is no standardised method of identifying AECOPD in UK EHR. We aimed to validate the recording of AECOPD in UK EHR.
  
  
  METHODS
  We randomly selected 1385 patients with COPD from the Clinical Practice Research Datalink. We selected dates of possible AECOPD based on 15 different algorithms between January 2004 and August 2013. Questionnaires were sent to GPs asking for confirmation of their patients' AECOPD on the dates identified and for any additional relevant information. Responses were reviewed independently by two respiratory physicians. Positive predictive value (PPV) and sensitivity were calculated.
  
  
  RESULTS
  The response rate was 71.3%. AECOPD diagnostic codes, lower respiratory tract infection (LRTI) codes, and prescriptions of antibiotics and oral corticosteroids (OCS) together for 5-14 days had a high PPV (>75%) for identifying AECOPD. Symptom-based algorithms and prescription of antibiotics or OCS alone had lower PPVs (60-75%). A combined strategy of antibiotic and OCS prescriptions for 5-14 days, or LRTI or AECOPD code resulted in a PPV of 85.5% (95% CI, 82.7-88.3%) and a sensitivity of 62.9% (55.4-70.4%).
  
  
  CONCLUSIONS
  Using a combination of diagnostic and therapy codes, the validity of AECOPD identified from EHR can be high. These strategies are useful for understanding health-care utilisation for AECOPD, informing service provision and for researchers. These results highlight the need for common coding strategies to be adopted in primary care to allow easy and accurate identification of events.
authors.affiliation: Respiratory Epidemiology, Occupational Medicine and Public Health, National Heart and Lung Institute, Imperial College London, London, United Kingdom.|Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Kieran J
authors.initials: KJ
authors.lastname: Rothnie
authors.affiliation: Respiratory Epidemiology, GSK R&D, Uxbridge, United Kingdom.
authors.forename: Hana
authors.initials: H
authors.lastname: Müllerová
authors.affiliation: UCL Respiratory Medicine, University College London, London, United Kingdom.
authors.forename: John R
authors.initials: JR
authors.lastname: Hurst
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.affiliation: Respiratory Epidemiology, GSK R&D, Collegeville, PA, United States of America.
authors.forename: Kourtney
authors.initials: K
authors.lastname: Davis
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Thomas
authors.affiliation: Respiratory Epidemiology, Occupational Medicine and Public Health, National Heart and Lung Institute, Imperial College London, London, United Kingdom.|Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Quint
mesh_terms: D000368:Aged; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology