Abstract 1579: Factors Contributing to Bleeding Risk in Patients Receiving Warfarin Therapy in the Community
Introduction: The purpose of this study was to examine the impact of psychosocial characteristics on susceptibility to warfarin induced bleeding. Previous studies have examined the impact of disease states, concomitant medication, older age and genetic factors on warfarin stability. However, there is limited information on the impact of individual psychosocial factors such as depression, cognition and health literacy and social isolation.
Hypothesis: Warfarin instability is more common amongst individuals influenced by adverse psychosocial factors.
Methods: A case control study comprised of 149 cases with an elevated INR (≥6.0) and 300 controls with an INR persistently within their therapeutic range. Cases and controls were recruited from a large metropolitan pathology provider and each was interviewed at either a recruitment centre or at their home by a trained researcher. Standardised measures to identify potential psychosocial risk factors included the Montreal Cognitive Assessment (MOCA), Geriatric Depression Scale (GDS-5), Duke Social Support Index (DSSI) and the Short Test of Functional Health Literacy in Adults (S-TOFHLA).
Results: Total of 449 patients: 149 cases (mean age 75.4 yrs, range 25–96) and 300 controls (mean age 75.5 yrs, range 36 –92) 46.2% of cases were female compared with 41.3% of controls. Mean duration of treatment was 7.3 (0.5–30) years in cases and 6.8 (0.6 –30) years. Atrial fibrillation was the most common indication for warfarin (44.8%). Psychosocial results are in the table⇓ below.
Conclusion: This study demonstrated that impaired cognitive function, depression, reported social isolation and low health literacy were strongly related to the likelihood of warfarin instability. Patients should be reviewed regularly in a holistic manner while on chronic anticoagulant treatment to identify any of these underlying characteristics.