Combination antibiotic therapy versus monotherapy for Pseudomonas aeruginosa bacteraemia: A meta-analysis of retrospective and prospective studies

The choice of antibiotic monotherapy or combination therapy to treat Pseudomonas aeruginosa bacteraemia is controversial. The aim of this review was to compare both types of therapy to determine which delivers the best outcome for P. aeruginosa bacteraemia. We systematically searched electronic bibliographic databases, including PubMed, Ovid EMBASE and The Cochrane Library, for clinical studies that compared combination therapy with monotherapy in the treatment of P. aeruginosa bacteraemia. Eligible articles were analysed using Stata®/SE software v.12.0. Stratification analysis was conducted by study design and treatment type. Publication bias was assessed using Begg's funnel plot and Egger's test. Ten studies (eight retrospective and two prospective) involving 1239 patients were analysed. We found no difference between combination therapy and monotherapy when the data were combined (odds ratio = 0.89, 95% confidence interval 0.57-1.40; P = 0.614) or when data were analysed in subgroups. Neither combination therapy nor monotherapy treatment appears to have a significant effect on mortality rates in patients with P. aeruginosa bacteraemia. Further studies evaluating the effects of combination therapy or monotherapy in more specialised cases, such as when encountering a multidrug-resistant organism, are necessary.