Purpose or Case Report: 1) Determine differences in characteristics of studies published within high impact radiology and medical journals journals in comparison to a Pediatric Radiology journal.

2) Outline factors that may have contributed to differences in quality of design of studies and components that could be incorporated into the design of future pediatric radiology research studies in order to improve their quality.
Methods & Materials: Original research articles published within the May – July 2015 issues of JAMA (2014 impact factor [IF], 35.3), Radiology (2014 IF, 6.9) and Pediatric Radiology (2014 IF, 1.6) journals were evaluated for study characteristics (research design, sample size, funding), author details (academic degrees, gender of first/senior authors) and institution (country, type of centre). Case reports, editorials and pictorial reviews were excluded from analysis.

‘Oxford Centre for Evidence-Based Medicine’ levels of evidence were used to grade the design quality of the published articles. The chi squared test was used to compare number of study characteristics between the three groups. Descriptive statistics were used to differentiate study design and author details.
Results: 148 articles were analysed (35 JAMA, 80 Radiology, 33 Pediatric Radiology). There was a significant difference in the number of prospective studies among the 3 groups (17(48.6%) vs. 42 (52.5%) vs. 6 (18.2%) respectively, p-value = 0.003), in number of studies with declared funding (32 (91.4%) vs. 48 (60%) vs. 6 (18.2%), p-value <0.0001) and in number of studies that used multicentre data (33 (94.3%) vs. 12 (15%) vs. 5 (15.2%), p-value <0001).

The median (range) sample sizes were 4513 (7 – 68,374,904), 100 (3 – 124,000,000) and 56 (7 - 3834) respectively. There were more systematic reviews and randomised controlled trials within JAMA (14, 40%) compared to within Radiology (1, 1.3%) and Pediatric Radiology (0, 0%). No radiology-related studies were published in JAMA during the period of investigation.
Conclusions: Fewer radiology studies than general medical studies are systematic reviews or randomised controlled trials, the hierarchically highest quality research designs. Pediatric radiology studies have smaller sample sizes compared with adult radiology and clinical studies, are less likely to be prospective or include multicentre data, likely due to lack of external funding support for most studies. Increased awareness of these factors may be helpful in guiding future pediatric radiology research.