title: Burden and risk factors of ambulatory or hospitalized CAP: A population based cohort study.
abstract: Data on incidence, risk factors and outcome of community-acquired pneumonia (CAP) including outpatients is sparse.
  
  
  
  We conducted a cohort study on 1.837.080 adults insured by a German statutory health insurance in 2010-2011. CAP was identified via ICD-10-GM codes, ambulatory cases were validated by antibiotic prescription within 7 days. Primary outcomes were incidence, hospitalisation and 30-day all-cause mortality. Evaluated risk factors included age, sex and comorbidities. Evaluation was done by multivariate regression analysis adjusting for these factors and health care utilization.
  
  
  
  CAP incidence was 9.7 per 1000 person years, hospitalisation rate 46.5%, and 30-day mortality 12.9%. 30-day mortality of ambulatory cases was 5% (with 27% subsequently hospitalized for another diagnosis before death). 30-day mortality of hospitalized patients was 21.9%, but in-hospital mortality 17.2%. Risk factors for CAP included age, male sex and all evaluated comorbidities with highest risk for neurologic (OR 2.4), lung (OR 2.3) or immunosuppressive (OR 2.1) disease. Mortality risk was highest for neurologic (OR 2.3) and malignant (OR 2.0) disease.
  
  
  
  CAP constitutes a major burden in terms of incidence, morbidity and all-cause mortality in hospitalized and ambulatory patients. Interventions to raise awareness for disease impact also in ambulatory patients with risk factors are warranted.
authors.affiliation: Division of Pulmonology, Medical Department I, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany. Electronic address: martin.kolditz@uniklinikum-dresden.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Kolditz
authors.affiliation: Dresden University Centre for Evidence-Based Healthcare, Medical Faculty, Technische Universität Dresden, Germany.
authors.forename: Falko
authors.initials: F
authors.lastname: Tesch
authors.affiliation: Dresden University Centre for Evidence-Based Healthcare, Medical Faculty, Technische Universität Dresden, Germany.
authors.forename: Luise
authors.initials: L
authors.lastname: Mocke
authors.affiliation: Division of Pulmonology, Medical Department I, University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany.
authors.forename: Gert
authors.initials: G
authors.lastname: Höffken
authors.affiliation: Thoraxzentrum Ruhrgebiet, Department of Respiratory and Infectious Diseases, EVK Herne and Augusta-Kranken-Anstalt Bochum, Germany.
authors.forename: Santiago
authors.initials: S
authors.lastname: Ewig
authors.affiliation: Dresden University Centre for Evidence-Based Healthcare, Medical Faculty, Technische Universität Dresden, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Schmitt
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000401:mortality; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology* / Q000401:mortality; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
keywords: Community-acquired pneumonia; Hospitalisation; Incidence; Mortality; Risk factor