Another example related to children - in 1993 guidance changed from having children sleep on their front to having them sleep on their backs. The result was a reduction in SIDS deaths from 0.13% to 0.035%. However the rate of kids having a flat spot on the back of their heads increased to 47% of 2 month olds. That flat spot pushes the rest of their skull forward and can result in a prominent forehead and misshapen features (iow, makes your kid ugly). Is the trade off between a 0.1% reduction in death rate worth a 50% chance of being ugly?