A pt has been recently added after a PE. Target range 2.0-3.00. Rec Dosage last week was 5.5mg per day on an INR of 2.2. Today it is 3.00, but when we enter this reading and click "recommendations" the above message comes up then it crashes with another message of "Run time error 13 - type mismatch".
Clearly 38.5mg per week is not too high and the increased INR should presumably reduce the recommended dosing anyway. So why does RAT not accept this?

dear John,
I think the reason is that RAT does not like using .5 dosing. You may have manually entered the new dose regimen, as RAT increments and decrements on 1mg doses per week.
'5.5mg per day' is not a recognised daily RAT dose.
It is crashing out as it cannot get a dose to go across the week evenly using .5 dosing.
Can you change the most recent historical weekly dose to a whole number then re-enter the INR to see if that fixes the problem.

(Also, it is generally not recommended to use 5mg nor 0.5mg warfarin tablets for safety reasons, though I don't know if you using these to get 5.5mg daily)

Colm

Yes this one has been manually edited. The GPs do this sometimes when they feel the pt will have problems with a dosing regime which is not the same every day.