Improving outcomes in elderly patients with community-acquired pneumonia by adhering to national guidelines: Community-Acquired Pneumonia Organization International cohort study results

Arch Intern Med. 2009 Sep 14;169(16):1515-24. doi: 10.1001/archinternmed.2009.265.


Background: To define whether elderly patients hospitalized with community-acquired pneumonia (CAP) had better outcomes if they were treated with empirical antimicrobial therapy adherent to the 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) guidelines for CAP.

Methods: This was a secondary analysis of the CAPO International Cohort Study database, which contained data from a total of 1725 patients aged 65 years or older who were hospitalized with CAP. Data from June 1, 2001, until January 1, 2007, were analyzed from 43 centers in 12 countries including North America (n = 2), South America (n = 4), Europe (n = 4), Africa (n = 1), and Southeast Asia (n = 1). Initial empirical therapy for CAP was evaluated for guideline compliance according to the 2007 IDSA/ATS guidelines for CAP. Time to clinical stability, length of stay (LOS), total in-hospital mortality, and CAP-related mortality for each group were calculated. Comparisons between groups were made using cumulative incidence curves and competing risks regression.

Results: Among the 1649 patients with CAP, aged 65 years or older, 975 patients were given antimicrobial regimens adherent to the IDSA/ATS for CAP guidelines, while 660 patients were treated with nonadherent regimens (465 patients were "undertreated"; 195 were "overtreated"). Adherence to guidelines was associated with a statistically significant decreased time to achieve clinical stability compared with nonadherence: the proportion of patients who reached clinical stability by 7 days was 71% (95% confidence interval [CI], 68%-74%) and 57% (95% CI, 53%-61%) (P < .01), respectively. Guideline adherence was also associated with shorter LOS (median adherence LOS, 8 days; interquartile range [IQR], 5-15 days; median nonadherence LOS, 10 days; IQR, 6-24 days) (P < .01) and decreased overall in-hospital mortality (8%; 95% CI, 7%-10% vs 17%; 95% CI, 14%-20%) (P < .01).

Conclusion: Implementation of national guidelines at the local hospital level will improve not only mortality and LOS of elderly patients hospitalized with CAP but also time to clinical stability.

Publication types

  • Multicenter Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anti-Infective Agents / therapeutic use*
  • Cohort Studies
  • Community-Acquired Infections / drug therapy
  • Drug Therapy, Combination
  • Female
  • Guideline Adherence*
  • Humans
  • Length of Stay
  • Male
  • Pneumonia / drug therapy*
  • Pneumonia / mortality
  • Retrospective Studies
  • beta-Lactams / therapeutic use*


  • Anti-Infective Agents
  • beta-Lactams