Well, unsure really how many hundred years an iPad would last for
Just think a very large hospital, with say, what 200, 300 members of staff with iPads.
Nice hygienic clean HARD floors.
Just how many iPads per day do you think you would be replacing due to smashed glass from being dropped?
Well, one has to assume that if initial trials go well, otter box-type ruggedization measures would be taken to protect the units.. The data would be on servers, not on the devices themselves, so even if it gets dropped and broken, the data is "safe".
Honestly, I'd be more worried about the ipad as a source of cross contamination of germs given the tactile interface... As it is, doctors ties are considered some of the biggest carriers of germs and sources of infections in hospitals, to the point that some hospitals have banned men from wearing them in the hospital.