Frequency
TIW
Three times weekly
Risk
Can be mistaken for "three times a day" or "twice weekly"
Safer Alternative
Write "3 times weekly"
Example
TIW misread as TID (three times daily)
Three times weekly
Can be mistaken for "three times a day" or "twice weekly"
Write "3 times weekly"
TIW misread as TID (three times daily)