FDA Video: Medical Errors from Misreading Letters and Numbers

An article by the Institute for Safe Medication Practices (ISMP) reminds healthcare practitioners how dangerous it can be to misread the letters and numbers on prescriptions, drug orders and medical records. Unfortunately, these mistakes are easy to make because some of the alphanumeric symbols we use look so similar.

Research has shown that more than 50 percent of letter-number errors come from just four basic mixups:
  • the letter "L" and the number "1"
  • the letter "O" and the number "0"
  • the letter "Z" and the number "2"
  • the numbers "1" and "7"
These mixups are most likely to occur when the information contains both letters and numbers, as in most medication orders.

The complete ISMP article, includes a list of more than 20 commonly confused letters and numbers.