title: Increasing burden of community-acquired pneumonia leading to hospitalisation, 1998-2014.
abstract: Community-acquired pneumonia (CAP) is a major cause of mortality and morbidity in many countries but few recent large-scale studies have examined trends in its incidence.
  
  
  
  Incidence of CAP leading to hospitalisation in one UK region (Oxfordshire) was calculated over calendar time using routinely collected diagnostic codes, and modelled using piecewise-linear Poisson regression. Further models considered other related diagnoses, typical administrative outcomes, and blood and microbiology test results at admission to determine whether CAP trends could be explained by changes in case-mix, coding practices or admission procedures.
  
  
  
  CAP increased by 4.2%/year (95% CI 3.6 to 4.8) from 1998 to 2008, and subsequently much faster at 8.8%/year (95% CI 7.8 to 9.7) from 2009 to 2014. Pneumonia-related conditions also increased significantly over this period. Length of stay and 30-day mortality decreased slightly in later years, but the proportions with abnormal neutrophils, urea and C reactive protein (CRP) did not change (p>0.2). The proportion with severely abnormal CRP (>100 mg/L) decreased slightly in later years. Trends were similar in all age groups. Streptococcus pneumoniae was the most common causative organism found; however other organisms, particularly Enterobacteriaceae, increased in incidence over the study period (p<0.001).
  
  
  
  Hospitalisations for CAP have been increasing rapidly in Oxfordshire, particularly since 2008. There is little evidence that this is due only to changes in pneumonia coding, an ageing population or patients with substantially less severe disease being admitted more frequently. Healthcare planning to address potential further increases in admissions and consequent antibiotic prescribing should be a priority.
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: T Phuong
authors.identifier: 0000-0001-8566-1817
authors.initials: TP
authors.lastname: Quan
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Fawcett
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: John M
authors.initials: JM
authors.lastname: Wrightson
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: John
authors.initials: J
authors.lastname: Finney
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: David
authors.initials: D
authors.lastname: Wyllie
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Katie
authors.initials: K
authors.lastname: Jeffery
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Jones
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Brian
authors.initials: B
authors.lastname: Shine
authors.affiliation: Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Lorraine
authors.initials: L
authors.lastname: Clarke
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Derrick
authors.initials: D
authors.lastname: Crook
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: A Sarah
authors.initials: AS
authors.lastname: Walker
authors.affiliation: NIHR Oxford Biomedical Research Centre, Oxford, UK Nuffield Department of Medicine, University of Oxford, Oxford, UK Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
authors.forename: Timothy E A
authors.initials: TE
authors.lastname: Peto
mesh_terms: D000328:Adult; D000368:Aged; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology; D004739:England / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology* / Q000382:microbiology
keywords: Pneumonia