Guideline adherence and macrolides reduced mortality in outpatients with pneumonia.

BACKGROUND

For outpatients with pneumonia, guidelines recommend empiric antibiotics and some suggest macrolides are preferred agents. We hypothesized that both guideline-concordant antibiotics and macrolides would be associated with reduced mortality.

METHODS

All outpatients with pneumonia assessed at 7 Emergency Departments in Edmonton, Alberta, Canada were enrolled in a population-based registry that included clinical-radiographic data, Pneumonia Severity Index (PSI) and treatments. Guideline-concordant regimens included macrolides and respiratory fluoroquinolones; other regimens were "discordant". Main outcome was 30-day all-cause mortality.

RESULTS

The study included 2973 outpatients; mean age 51 years, 47% female, most had mild pneumonia (73% PSI Class I-II). Over 30-days, 38 (1%) patients died, 228 (8%) were hospitalized, and 253 (9%) reached the endpoint of death or hospitalization. Most (2845 [96%]) patients received guideline-concordant antibiotics. Compared to patients receiving discordant antibiotics, those receiving guideline-concordant antibiotics were less likely to die within 30-days (8 [6%] versus 30 [1%], adjusted OR 0.23, 95% CI 0.09-0.59, p = 0.002). Within the guideline-concordant subgroup, compared to the 947 (33%) patients treated with fluoroquinolones, those receiving macrolides [1847 (64%)] were less likely to die (25 [3%] versus 4 [0.2%], adjusted OR 0.28, 95% CI 0.09-0.86, p = 0.03).

CONCLUSIONS

In outpatients with pneumonia, treatment with guideline-concordant antibiotics and macrolides were both associated with mortality reduction.