National clinical practice guidelines have recommended specific empiric antimicrobial regimes for patients with community-acquired pneumonia (CAP). However, there is controversy over whether there are modifiable factors that may impact mortality during the first 48 hours after admission, and little evidence whether the use of guideline-concordant antimicrobials during this time may be beneficial. Our aim was to determine whether the use of guideline-concordant antibiotic therapy is associated with decreased mortality within the first 48 hours after admission for patients with CAP.
Eligible patients were admitted with a diagnosis of CAP between 1/1/1999 and 12/1/2001 from two tertiary teaching hospitals, had a chest x-ray consistent with CAP, and had a primary or secondary ICD-9 diagnosis of pneumonia. Patients were excluded if they were “comfort measures only” or transferred from another acute care hospital. A propensity score was used to balance the covariates associated with the use of guideline-concordant antimicrobial therapy. A multivariable logistic regression model was used to assess the association between mortality within 48 hours, and the use of guideline-concordant antibiotic therapy, after adjusting for potential confounders including the propensity score and severity of illness.
Information was obtained on 787 patients with CAP. The median age was 60 years, 79% were male, and 20% were initially admitted to the ICU. At presentation 52% of subjects were low risk, 34% were moderate risk, and 14% were high risk. 20 patients died within the first 48 hours. After adjusting for potential confounders, the use of guideline-concordant antimicrobial therapy (odds ratio 0.37, 95% confidence interval 0.14-0.95) was significantly associated with decreased mortality at 48 hours.
Using initial empiric guideline-concordant antimicrobial therapy is associated with decreased mortality at 48 hours after admission.
Further research is needed to determine what are appropriate empiric antimicrobial therapies for patients with CAP.
Eric Mortensen, None.