This is a survey of the top twelve Emergency Medicine journals, as ranked by impact factor, providing a descriptive analysis of the features of the studies contained within. The authors manually reviewed 330 articles and found a mere 8.8% were randomized studies. Most (65.5%) were cross-sectional studies and 23.6% were cohort studies. 57.3% were prospective, 47.9% were from the U.S., and the minority of studies (31.2%) used informed consent or mentioned waivers of informed consent.
Of course, this will then only exacerbate the bias inherent in the already U.S.-centric published literature.
"Quality of publications in emergency medicine"