Skip to content | Change text size

Medication Safety- Projects

The Centre of Research in Patient Safety will investigate how social, relational, and organizational structures contribute to medication error using cognitive engineering and human factors techniques.

Warfarin complications in the community

Investigators: John McNeil, Peter Cameron, Michael Dooley, Ellen Maxwell, Rory Wolfe, Sue Evans, Alison Street, Leon Piterman, Basia Diug, Judy Lowthian
Project Coordinator: Judy Lowthian
Background: Warfarin is the mainstay of prophylaxis against stroke in atrial fibrillation and valve replacement. Warfarin’s narrow therapeutic window necessitates close monitoring of the International Normalised Ratio (INR) as numerous factors are recognised to increase or reduce its
anticoagulation effect. Despite its efficacy, it remains one of the most common drug-related causes of death and morbidity, with increased bleeding tendency as the major adverse effect of warfarin.
Aims: The aim of this project is to reduce the amount of unnecessary bleeding due to warfarin, by identifying predisposing factors and potential system of care issues amongst patients with significantly elevated INR levels; and to develop a preliminary risk profile of patients being treated with warfarin who record elevated INR levels in the blood. We hypothesize that people with an elevated INR level will have a different profile compared to those people who maintain an INR level within a
therapeutic range.
Method: Based in metropolitan Melbourne this project is being conducted in collaboration with Melbourne Pathology, and consists of two phases. The pilot study was completed in 2007, and interviewed 40 patients with INRs ≥ 6, and their primary treating doctors. The current case control study comprises 450 patients, 150 cases and 300 controls. Patients are eligible if they are aged ≥18 years, reside in the community, provide informed consent and have been on warfarin for a minimum of 6 months. Additionally, cases have recently developed an INR ≥ 6.0, whilst controls have been well stabilised for a minimum of 3 months. Patient interviews investigate potential predisposing factors including demographic and clinical characteristics, comorbidities, diet, medication, and warfarin knowledge. Standardised measures evaluate cognition, mood, social support, functional independence, and adherence and medication complexity.
Status: Recruitment of patients and data collection phase.
Publications:  Lowthian J, Evans S. Management of Atrial Fibrillation. Australian Family Physician 2007; 36(10):791; Diug B, Lowthian J, Evans S. Warfarin versus Aspirin for Stroke Prevention. Lancet 2007; 370(9599):1606;Lowthian J, Diug B. Lessons from the TAPS study- warfarin: a major cause of threats to patient safety. AFP 2008 37(12):983
Student/s: Basia Diug
Publications:

  1. Lowthian J, Evans S. Management of Atrial Fibrillation. Australian Family Physician 2007; 36(10):791
  1. Lowthian J, Diug B. Lessons from the TAPS study- warfarin: a major cause of threats to patient safety. AFP 2008 37(12):983

Contact Person:Basia Diug - basia.diug@med.monash.edu.au