Purpose: We developed a pneumonia guideline at Intermountain Health Care that included admission decision support and recommendations for antibiotic timing and selection, based on the 1993 American Thoracic Society guideline. We hypothesized that guideline implementation would decrease mortality.

Subjects and methods: We included all immunocompetent patients > 65 years with community-acquired pneumonia from 1993 through 1997 in Utah; nursing home patients were excluded. We compared 30-day mortality rates among patients before and after the guideline was implemented, as well as among patients treated by physicians who did not participate in the guideline program.

Results: We observed 28,661 cases of pneumonia, including 7,719 (27%) that resulted in hospital admission. Thirty-day mortality was 13.4% (1,037 of 7,719) among admitted patients and 6.3% (1,801 of 28,661) overall. Mortality rates (both overall and among admitted patients) were similar among patients of physicians affiliated and not affiliated with Intermountain Health Care before the guideline was implemented. For episodes that resulted in hospital admission after guideline implementation, 30-day mortality was 11.0% among patients treated by Intermountain Health Care-affiliated physicians compared with 14.2% for other Utah physicians. Analysis that adjusted by logistic regression for age, sex, rural versus urban residences, and year confirmed that 30-day mortality was lower among admitted patients who were treated by Intermountain Health Care-affiliated physicians (odds ratio [OR]: 0.69; 95% confidence interval [CI]: 0.49 to 0.97; P = 0.04) and was somewhat lower among all pneumonia patients (OR: 0.81; 95% CI: 0.63 to 1.03; P = 0.08).

Conclusion: Implementation of a pneumonia practice guideline in the Intermountain Health Care system was associated with a reduction in 30-day mortality among elderly patients with pneumonia.