In-hospital observation after antibiotic switch in pneumonia: a national evaluation

Am J Med. 2006 Jun;119(6):512.e1-7. doi: 10.1016/j.amjmed.2005.09.012.


Purpose: To evaluate the clinical benefit of in-hospital observation after the switch from intravenous (IV) to oral antibiotics in a large Medicare population. Retrospective studies of relatively small size indicate that the practice of in-hospital observation after the switch from IV to oral antibiotics for patients hospitalized with community-acquired pneumonia (CAP) is unnecessary.

Methods: We performed a retrospective examination of the US Medicare National Pneumonia Project database. Eligible patients were discharged with an ICD-9-CM diagnosis consistent with community-acquired pneumonia and divided into 2 groups: 1) a "not observed" cohort, in which patients were discharged on the same day as the switch from IV to oral antibiotics and 2) an "observed for 1 day" cohort, in which patients remained hospitalized for 1 day after the switch from IV to oral antibiotics. We compared clinical outcomes between these 2 cohorts.

Results: A total of 39,242 cases were sampled, representing 4341 hospitals in all 50 states and the District of Columbia. There were 5248 elderly patients who fulfilled eligibility criteria involving a length of stay of no more than 7 hospital days (2536 "not observed" and 2712 "observed for 1 day" patients). Mean length of stay was 3.8 days for the "not observed" cohort and 4.5 days for the "observed for 1 day" cohort (P <.0001). There was no significant difference in 14-day hospital readmission rate (7.8% in the "not observed" cohort vs 7.2% "observed for 1 day" cohort, odds ratio 0.91; 95% confidence interval [CI] 0.74-1.12; P =.367) and 30-day mortality rate (5.1% "not observed" cohort vs 4.4% in the "observed for 1 day" cohort, odds ratio 0.86; 95% CI, 0.67-1.11; P =.258) between the "not observed" and "observed for 1 day" cohorts.

Conclusions: Our analysis of the US Medicare Pneumonia Project database provides further evidence that the routine practice of in-hospital observation after the switch from IV to oral antibiotics for patients with CAP may be avoided in patients who are clinically stable although these findings should be verified in a large randomized controlled trial.

Publication types

  • Evaluation Study
  • Multicenter Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Administration, Oral
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / administration & dosage*
  • Community-Acquired Infections / drug therapy
  • Confounding Factors, Epidemiologic
  • Female
  • Health Services Research
  • Humans
  • Infusions, Intravenous
  • Inpatients / statistics & numerical data*
  • Length of Stay* / economics
  • Male
  • Medicare
  • Observation
  • Odds Ratio
  • Patient Readmission / statistics & numerical data
  • Pneumonia, Bacterial / drug therapy*
  • Pneumonia, Bacterial / economics
  • Pneumonia, Bacterial / transmission
  • Research Design
  • Retrospective Studies
  • Treatment Outcome
  • United States


  • Anti-Bacterial Agents