Patient safety is ensuring the avoidance of accidental medical injury or iatrogenic injury while receiving medical care. Medical errors occur in hospitals, clinics & pharmacies. Or patient may end up buying wrong medicines due to doctor's illegible handwriting.
Legibility - http://en.wikipedia.org/wiki/Medical_prescription
Prescriptions, when handwritten, are notorious for being often illegible (5% according to an Irish study.]). In the US,
sloppy handwriting kills more than 7,000 people annually", "according to a July 2006 report from the National Academies of Science's Institute of Medicine (IOM)". Pharmacists do not have special deciphering skills, when in doubt, they call the medical practitioner. At other times, even though some of the individual letters are illegible, the position of the legible letters and length of the word is sufficient to distinguish the medication based on the knowledge of the pharmacist. Some jurisdictions have made legible prescriptions a law (e.g. Florida. Some have advocated the elimination of handwritten prescriptions altogether and computer
printed prescriptions are increasingly common.