They say "medicine". I would say science in general, perhaps we could generalise even further to "any human activity is full of unethical people trying to exploit it". But 25%!? That suggest there is a big problem with how we "do science". Unfortunately I have no solution to the problem. Publishing everything (including raw data) for every research would probably help somewhat, but only teams repeating experiments/trials would ensure it.

I wonder if we suddenly took 10% of all money spent on science (let's say in medicine) and instead of novel research we used it to redo randomly chosen previous research. Would we loose or gain in terms of new cures? And if we gained, what if we spent 15%, or 25%? That's a great idea for a scientific study to find a point of diminishing returns on "research verification".

Would someone please write a research grant request for this?