title: Patient characteristics associated with risk of first hospital admission and readmission for acute exacerbation of chronic obstructive pulmonary disease (COPD) following primary care COPD diagnosis: a cohort study using linked electronic patient records.
abstract: OBJECTIVE
  To investigate patient characteristics of an unselected primary care population associated with risk of first hospital admission and readmission for acute exacerbation of chronic obstructive pulmonary disease (AECOPD).
  
  
  METHODS
  Retrospective open cohort using pseudonymised electronic primary care data linked to secondary care data.
  
  
  METHODS
  Primary care; Lothian (population approximately 800,000), Scotland.
  
  
  METHODS
  Data from 7002 patients from 72 general practices with a COPD diagnosis date between 2000 and 2008 recorded in their primary care record. Patients were followed up until 2010, death or they left a participating practice.
  
  
  METHODS
  First and subsequent admissions for AECOPD (International Classification of Diseases (ICD) 10 codes J44.0, J44.1 in any diagnostic position) after COPD diagnosis in primary care.
  
  
  RESULTS
  1756 (25%) patients had at least 1 AECOPD admission; 794 (11%) had at least 1 readmission and the risk of readmission increased with each admission. Older age at diagnosis, more severe COPD, low body mass index (BMI), current smoking, increasing deprivation, COPD admissions and interventions for COPD prior to diagnosis in primary care, and comorbidities were associated with higher risk of first AECOPD admission in an adjusted Cox proportional hazards regression model. More severe COPD and COPD admission prior to primary care diagnosis were associated with increased risk of AECOPD readmission in an adjusted Prentice-Williams-Peterson model. High BMI was associated with a lower risk of first AECOPD admission and readmission.
  
  
  CONCLUSIONS
  Several patient characteristics were associated with first AECOPD admission in a primary care cohort of people with COPD but fewer were associated with readmission. Prompt diagnosis in primary care may reduce the risk of AECOPD admission and readmission. The study highlights the important role of primary care in preventing or delaying a first AECOPD admission.
authors.affiliation: Department of Public Health and Health Policy, NHS Lothian, Edinburgh, Midlothian, UK.
authors.forename: L C
authors.initials: LC
authors.lastname: Hunter
authors.affiliation: Centre for Population Health Sciences, Medical School, University of Edinburgh, Edinburgh, Midlothian, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Lee
authors.affiliation: Centre for Population Health Sciences, Medical School, University of Edinburgh, Edinburgh, Midlothian, UK.
authors.forename: I
authors.initials: I
authors.lastname: Butcher
authors.affiliation: Reader in Medical Statistics and Associate Director (Statistics) Health Services Research Unit, Centre for Population Health Sciences, Medical School, University of Edinburgh, Edinburgh, Midlothian, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Weir
authors.affiliation: Clinical Director for Information Services, Information Services Division (ISD), NHS National Services Scotland, Edinburgh, Midlothian, UK.
authors.forename: C M
authors.initials: CM
authors.lastname: Fischbacher
authors.affiliation: Usher Institute of Population Health Sciences and Informatics, Medical School, University of Edinburgh, Edinburgh, Midlothian, UK.
authors.forename: D
authors.initials: D
authors.lastname: McAllister
authors.affiliation: Usher Institute of Population Health Sciences and Informatics, Medical School, University of Edinburgh, Edinburgh, Midlothian, UK.
authors.forename: S H
authors.initials: SH
authors.lastname: Wild
authors.affiliation: Clinical Lead, Lothian Respiratory Managed Clinical Network, NHS Lothian, Edinburgh, Midlothian, UK.
authors.forename: N
authors.initials: N
authors.lastname: Hewitt
authors.affiliation: Department of Public Health and Health Policy, NHS Lothian, Edinburgh, Midlothian, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Hardie
mesh_terms: D000367:Age Factors; D015992:Body Mass Index; D018450:Disease Progression; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008297:Male; D010343:Patient Admission / Q000706:statistics & numerical data; D010359:Patient Readmission / Q000706:statistics & numerical data; D011320:Primary Health Care; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000628:therapy*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D012907:Smoking
keywords: PRIMARY CARE