Prescriber guidelines improve initiation of anticoagulation

To improve the initiation of anticoagulation in patients with thrombotic disorders.

We carried out a preliminary audit in 1991, developed and implemented strategies to address identified problems, and followed up with another audit in 1993. Medical records of inpatients at The Royal Melbourne Hospital whose anticoagulation therapy was initiated with heparin (intravenous) in therapeutic doses and subsequently converted to warfarin were prospectively assessed over 19-day periods.

Pocket-sized laminated prescriber guidelines for initiating anticoagulation were disseminated after publishing the results of the first audit, together with a single prominent display of two posters in series advocating the use of the guidelines.

The audits identified 25 eligible patients in 1991 and 27 in 1993. The mean duration of intravenous heparin therapy was reduced from 150 hours in 1991 to 97 hours in 1993 (P < 0.002). The mean delay before initiating warfarin therapy after starting heparin therapy was reduced from 69 hours in 1991 to 21 hours in 1993 (P < 0.002). The mean percentage of time the activated partial thromboplastin time was within the therapeutic range increased from 30% in 1991 to 44% in 1993 (P < 0.05) and was above the therapeutic range increased from 13% in 1991 to 24% in 1993 (P < 0.01). Although the number of adverse events was too small to draw definitive conclusions, no difference in adverse haemorrhagic effects was noted between the 1991 and 1993 groups.

There was an improvement in the initiation of anticoagulation and we hypothesise that this was most likely due to a broad acceptance of the guidelines into clinical practice.