Characteristics and Quality of Radiologic Randomized Controlled Trials: A Bibliometric Analysis Between 1995 and 2014

OBJECTIVE: The aim of this bibliometric study was to assess the characteristics and quality of radiologic randomized controlled trials (RCTs) over the past 20 years. MATERIALS AND METHODS: A PubMed search was conducted to identify radiologic RCTs (defined as RCTs in which the first author or corresponding author is affiliated with a radiology department) published between 1995 and 2014. The following information was extracted from each article: journal, radiologic subspecialty, imaging technique, number of subjects, study result, funding, number of authors, number of institutions, country of origin, and methodologic quality (assessed using the Jadad scale). RESULTS: A total of 358 radiologic RCTs were published between 1995 and 2014. Dramatic increases in the numbers of radiologic RCTs were found, from 43 conducted in 1995-1999 to 172 conducted in 2010-2014. One-hundred seventeen (32.7%) RCTs were concerned with the field of vascular and interventional radiology; 78 (21.8%) evaluated more than one imaging technique; 164 (45.8%) had a sample size of 50-150 subjects; 246 (68.7%) showed positive study results; 185 (51.7%) were not funded; 179 (50.0%) had four to seven authors; 263 (73.5%) were single-center trials; 88 (24.6%) had a first author or corresponding author located in the United States; and 187 (52.2%) were of low quality. In the time trend analysis, the following variables showed a significantly positive trend: abdominal imaging subspecialty, CT as the imaging technique, more than 150 subjects, more than seven authors, and high methodologic quality. CONCLUSION: The quantity and quality of radiologic RCTs have significantly increased over the past 2 decades; however, the methodologic quality remains suboptimal.