The dilemma of monotherapy or combination therapy in community‐acquired pneumonia

Scope To study the factors associated with mortality in hospitalized patients with community‐acquired pneumonia treated with monotherapy or combination therapy. Methods PubMed and Scopus were searched. Patients receiving macrolides, β‐lactams and fluoroquinolones, as monotherapy or in combination, were included. Meta‐analyses and meta‐regressions were performed. Results Fifty studies were included. Overall, monotherapy was not associated with higher mortality than combination (RR 1.14, 95% CI 0.99‐1.32, I2 84%). Monotherapy was associated with higher mortality than combination in North American and retrospective studies. β‐lactam monotherapy was associated with higher mortality than β‐lactam/macrolide combination in the primary (1.32, 1.12‐1.56, I2 85%) and most sensitivity analyses. There was no difference in mortality between fluoroquinolone monotherapy and β‐lactam/macrolide combination (0.98, 0.78‐1.23, I2 73%). In meta‐regressions, the moderators that could partially explain the observed statistical heterogeneity were the frequency of cancer patients (P = .03) and Pneumonia Severity Index score IV (P = .008). Conclusion Due to the considerable heterogeneity and inclusion of unadjusted data, it is difficult to recommend a specific antibiotic regimen over another. Specific antibiotic regimens, study design and the characteristics of the population under study seem to influence the reported outcomes.