title: Risk factors for drug-resistant bacterial pneumonia in older patients hospitalized with pneumonia in a Chinese population.
abstract: BACKGROUND
  The relationship between healthcare-associated pneumonia (HCAP) and resistant bacteria is unclear. The aim of this study was to identify the risk factors for pneumonia caused by drug-resistant bacteria (DRB).
  
  
  METHODS
  A prospective cohort study was conducted at a tertiary teaching hospital in Hong Kong. Consecutive older patients (aged ≥65 years) were hospitalized with pneumonia from January 2004 to June 2005. DRB comprised methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae and Acinetobacter baumannii.
  
  
  RESULTS
  The entire cohort consisted of 1176 older patients. Of 472 (40.1%) patients with etiological diagnosis established, bacterial pneumonia was found in 354 (30.1%) cases. DRB were isolated in 48 patients: P. aeruginosa (41), MRSA (5) and ESBL producing enteric bacilli (3). Co-infection with P. aeruginosa and MRSA was found in one patient. The prevalence of DRB in culture-positive pneumonia was 20.1% (48/239). Patients with DRB were more likely to have limitation in activities of daily living, bronchiectasis, dementia, severe pneumonia, recent hospitalization and recent antibiotic use. Logistic regression revealed that bronchiectasis [relative risk (RR) 14.12, P = 0.002], recent hospitalization (RR 4.89, P < 0.001) and severe pneumonia (RR 2.42, P = 0.010) were independent predictors of drug-resistant bacterial pneumonia.
  
  
  CONCLUSIONS
  Recent hospitalization is the only risk factor for HCAP which is shown to be associated with DRB. Nursing home residence is not a risk factor. The concept of HCAP may not be totally applicable in Hong Kong where the prevalence of drug-resistant pathogens in pneumonia is low.
authors.affiliation: Department of Medicine and Therapeutics, 9/F, Clinical Science Building, Prince of Wales Hospital, The Chinese University of Hong Kong, 32 Ngan Shing Street, Shatin, NT, HKSAR. hmma@cuhk.edu.hk.
authors.forename: H M
authors.initials: HM
authors.lastname: Ma
authors.forename: Margaret
authors.initials: M
authors.lastname: Ip
authors.forename: Jean
authors.initials: J
authors.lastname: Woo
authors.forename: David S C
authors.initials: DS
authors.lastname: Hui
authors.forename: Grace C Y
authors.initials: GC
authors.lastname: Lui
authors.forename: Nelson L S
authors.initials: NL
authors.lastname: Lee
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Chan
authors.forename: T H
authors.initials: TH
authors.lastname: Rainer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001987:Bronchiectasis / Q000150:complications; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003428:Cross Infection; D024881:Drug Resistance, Bacterial; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus; D018410:Pneumonia, Bacterial / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology*; D011023:Pneumonia, Staphylococcal; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents