It takes an average of seventeen years for the data that exposes inefficacy and/or a signal of harm to trickle down into your doctor’s daily routine, a time lag problem that makes medicine’s standard of care evidence-based only in theory and not practice.

Z. S. Morris, S. Wooding, and J. Grant, “The Answer Is 17 Years, What Is the Question: Understanding Time Lags in Translational Research,” Journal of the Royal Society of Medicine 104, no. 12 (December 2011): 510–20, doi:10.1258/jrsm.2011.110180.)