Anticoagulant use and associated outcomes in older patients receiving home palliative care: A retrospective cohort study

Abstract

Background: The benefits and harms of anticoagulants for people near the end of life are not well understood, nor is it known what proportion of patients discontinue these medications. We aimed to characterize anticoagulant use in older recipients of home palliative care and describe patient and provider characteristics, as well as outcomes associated with anticoagulant discontinuation in this group. Methods: Using linked administrative health databases, we conducted a population-based cohort study of patients aged 66 years and older who initiated home palliative care in Ontario from 2010 to 2018. We calculated the prevalence of anticoagulant use. We used multilevel logistic regression models to assess patient (e.g., sociodemographic, comorbidities) and physician (e.g., demographic, training, practice) factors associated with anticoagulant discontinuation after initiation of home palliative care. We defined discontinuation as either primary (no anticoagulant claim within 1.5 times the days' supply of the previous prescription) or secondary (no subsequent anticoagulant claim at any time after the index date). In secondary analyses, we used causespecific hazards regression to explore subsequent thrombotic and bleeding events associated with anticoagulant discontinuation, and multivariable logistic regression for location of death. Results: We identified 98 089 recipients of home palliative care, of whom 15.5% were taking anticoagulants at the time of the first palliative care visit. Depending on the definition of discontinuation, 18.0% to 24.4% of patients discontinued anticoagulants after the first home palliative care visit. Compared with warfarin, use of a direct oral anticoagulant (adjusted odds ratio [OR] 0.49, 95% confidence interval [CI] 0.43-0.56) and lowmolecular-weight heparin (adjusted OR 0.56, 95% CI 0.47-0.66) were associated with a lower likelihood of discontinuation. Few patient or physician characteristics - and no comorbidities or indications for therapeutic anticoagulation - were associated with discontinuation. Anticoagulant discontinuation after beginning home palliative care was associated with similar rates of thrombosis (adjusted hazard ratio [HR] 1.06, 95% CI 0.81-1.39), lower rates of bleeding (adjusted HR 0.75, 95% CI 0.62-0.90) and a higher likelihood of a home death (adjusted OR 1.22, 95% CI 1.09-1.36) compared with continuing anticoagulation. Interpretation: Among recipients of home palliative care in Ontario, anticoagulant use is common, and discontinuation is not influenced by comorbidities or indication for anticoagulation. Physician preference may play an important role; patients should be made aware of their options toward the end of life and supported in shared decision-making.