Volume 191 - Issue 10
Who is responsible for the care of patients treated with warfarin therapy?
Author: John C Roberts
Med J Aust 2009; 191 (10): 575-577. || doi: 10.5694/j.1326-5377.2009.tb03323.x
Published online: 16 November 2009
Published online: 16 November 2009
To the Editor: Lowthian and colleagues ask who is responsible for the care of patients treated with warfarin therapy.1 In Melbourne, it seems that this devolves mainly upon the pathology laboratory, whereas in other states, general practitioners manage care for their own patients, in my own experience.
Where management of warfarin dosing, based on the international normalised ratio (INR) result, is performed by the laboratory, this is done as a courtesy to GPs. This practice possibly evolved from competition between private laboratories and, as such, may have been intended to induce other pathology requests to the service provider.
Larger metropolitan private pathology services may have sufficient pathologists with haematology training to provide warfarin dosing to patients, but this may not always apply in smaller laboratories. In some laboratories, warfarin dosing may be provided to patients by scientific staff. Although warfarin therapy can sometimes be challenging, its difficulties are not usually insurmountable.
Problems for pathologists arise because they are expected to give a warfarin dose by telephone to a patient they do not know and have never seen. The patient’s phone number may be not supplied or incomplete, and the call may not be answered. If answered, a brief history of previous INR results, dosages and test intervals may or may not be elicited from a person who may have poor English, who may be the patient, a relative, friend or neighbour; or a message may have to be left. If the message is received, it may not be acted on, depending on memory, understanding or level of compliance. If the message is not received, the patient and the patient’s GP may be unreasonably irate, even though multiple attempts to contact the patient may have been made. It is not hard to understand why some GPs prefer to pass this often frustrating and time-consuming aspect of treatment to pathologists — who may also be pressed for time.
Problems are further compounded if warfarin dosing devolves to pathology laboratory scientists, which may be required by their employer. Scientists would be, in effect, performing drug dosing without medical training or medical registration and may be exposing themselves to litigation risk, without carrying medical indemnity.
In other Australian states, it seems that GPs do provide treatment and dosing of warfarin for their own patients. In my view, this is the safest and most satisfactory outcome for patients, pathologists and scientists. With the projected advent of point-of-care testing with reliable INR results2 and new anticoagulant alternatives1 that would enable easier management of anticoagulant therapy by GPs, this whole issue could potentially be resolved.
Competing interests
I am an employee of a private pathology company. I have provided warfarin dosing as both a pathologist and a GP.
References
- Lowthian JA, Diug BO, Evans SM, et al. Who is responsible for the care of patients treated with warfarin therapy? Med J Aust 2009; 190: 674-677. 0_CHDBFIGH
- Nagle D. AMA welcomes PoCT final report. Australian Medicine 2009; 21 (12): 4, 6. 0_pgfId-1964533