INRs: Report to One Decimal

We have been reporting INRs as only one decimal as 1.2 . We did this from the suggestions from CAP and their surveys. Also we have always rounded PTTs to a whole number. Should we be reporting 2 decimals on the INR and one on the PTTs? Thanks.

Diane Thornton
Section Supervisor Hematology
St. John’s Regional Medical Center Laboratory
Joplin, MO

Hi, Diane, thanks for your question. There is no clinical need to report the INR to two decimals, and according to the rules of significant numbers, the math supports reporting only to tenths. For the PTT, whole numbers are correct, though I know of some labs that report halves, for example 35.5. PTs are typically reported to tenths. Geo.