A study undertaken by a Cannegieter, Rosandaal, Wintzen et al Reference: The New England Journal of Medicine, 1995 ;333:11-17 shows the complication or incident rate with corresponding INR level see Figure below.

Patients usually move into the risk areas below 1.8 and above 5.5 INR as follows

Incidence of all adverse events (all thromboemboli, major bleeds, and strokes) by intensity of anticoagulation. INR-specific incidence rates for all major adverse events per 100 person –years. The dotted lines are the 95% confidence intervals around the incidence.

Here is how Dawn AC helps reduce these risks.

As mentioned in the Randomised Study (Ref, Poller et al, The Lancet, vol,352 no.9139 pages 1505-1509) Dawn AC achieved 20% to 30% better control in terms of our algorithm (see model two) than experienced Healthcare Professionals. See Graph

Assuming that with the better information provided by the Dawn AC computer service, besides the dosing ability, then GP’s, Specialists and nursing staff are altogether better informed of the patients status, this will without doubt contribute to the lowering of the major incidence rate.

For example, the GP doesn’t prescribe an interacting drug, the computer keeps the GP informed of the patients status, with out creating a huge administration burden.

The computer system could also be used to remind the Patient to tell the GP they are on Warfarin, say, on a six monthly basis, whilst perhaps also reminding them of dietary contributions to their welfare. With this added benefit to patient management you are then facilitating an even greater impact to limit the inadvertent prescription of an interacting drug and reminding the patient of which foods to be aware of , thus, making a considerable contribution to the reduction of the Major incidence rate.