A CNN health article from a while back says:
Experts say up to 25 percent of medication errors may be related to illegible handwriting: A pharmacist misreads an illegible prescription, one drug is mixed up with another. [...]The article mentions handwriting seminars being given to doctors, and says the following
Also last year the Institute of Medicine, an arm of the National Academy of Sciences, reported that medical mistakes overall -- including those stemming from unreadable notes from doctors -- may cause up to 98,000 deaths a year in the United States. Other researchers later termed those numbers exaggerated, but the authors stood by their report.
"It's good they're doing a seminar, but I'm surprised they're not going with automated bedside and hand-held computers, which cut the errors by up to 50 percent," Inlander said. Such devices require doctors and others to type orders into a computer system.