[DanaC]

Originally Posted by sexobon

Numbers can lie. They don't take into account human behavior. 98% is a statistical certainty, 95% a statistical probability regardless of human behavior. People may take excessive risks in other areas of infection control to their detriment with masks less than 95% effective.

Case in point: years ago, lumbar support belts were recommended by OSHA for workers doing heavy lifting. Employers wanted them used to reduce employee down time and workmen's compensation claims. Insurance companies wanted them used to reduce payouts which they wouldn't give unless the support belts were being worn at time of injury. Governments wanted them used to demonstrate their concern for the health and welfare of their constituents.. The prevailing thought was that anything was better than nothing and OSHA went along with it.

In practical application, employees started doing heavy lifting that they wouldn't have previously done, without help, thinking that the support belts would protect them and give them more time to do their jobs rather than waiting for assistance. The number of injuries shot up dramatically and it became an industry crisis. Employers balked, insurance companies balked, and governments balked as injured employees sued anyone they could over the misrepresentation that they would be safer wearing support belts; because, anything was better than nothing. OSHA not only retracted their recommendation, they specifically recommended against it.

Using numbers without factoring in human behavior is a fool's game.

Really good point.