Comparing the quantity and quality of randomised placebo-controlled trials of antibiotics for acute respiratory, urinary, and skin and soft tissue infections: a scoping review

BACKGROUND: The management of acute respiratory infections (ARIs), urinary tract infections (UTIs), and skin and soft tissue infections (SSTIs) should be guided by high quality evidence. AIM: To compare the quantity and quality of randomised placebo-controlled trials of antibiotics for ARIs, UTIs, and SSTIs. DESIGN & SETTING: A scoping review of the literature was performed using comprehensive search strategies. METHOD: PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for published studies from inception until 17 April 2019. Randomised controlled trials (RCTs) that compared participants in primary care or in the community who had uncomplicated acute ARI, UTI, or studies, and were randomised to antibiotic or placebo (or no active treatment), were eligible for inclusion. Two groups of researchers independently screened articles for inclusion, extracted data, and assessed the quality of included studies. RESULTS: A total of 108 eligible studies were identified: 80 on ARI, eight on UTI, and 20 on SSTI. The quality of studies varied with unclear risk of bias (RoB) prevalent in many domains. There was a gradual improvement in the quality of trials investigating ARIs over time, which could not be assessed in SSTI and UTI studies. CONCLUSION: This review highlights a sparsity of trials assessing the effectiveness of antibiotics in people with UTIs and SSTIs, compared to trials targeting ARIs. This gap in the evidence needs to be addressed by conducting further high quality trials on the effects of antibiotics in patients with UTI and SSTI.