Influence of Age on Warfarin Dose, Anticoagulation Control, and Risk of Hemorrhage
dc.contributor.author | Shendre, Aditi | |
dc.contributor.author | Parmar, Gaurav M. | |
dc.contributor.author | Dillon, Chrisly | |
dc.contributor.author | Beasley, T. Mark | |
dc.contributor.author | Limdi, Nita A. | |
dc.contributor.department | Epidemiology, School of Public Health | en_US |
dc.date.accessioned | 2018-03-07T15:52:42Z | |
dc.date.available | 2018-03-07T15:52:42Z | |
dc.date.issued | 2018 | |
dc.description.abstract | Objective We assessed the influence of age on warfarin dose, percentage time in target range (PTTR), and risk of major hemorrhage. Design Warfarin users recruited into a large prospective inception cohort study were categorized into three age groups: young (younger than 50 yrs), middle aged (50–70 yrs), and elderly (older than 70 yrs). The influence of age on warfarin dose and PTTR was assessed using regression analysis; risk of major hemorrhage was assessed using proportional hazards analysis. Models were adjusted for demographic, clinical, and genetic factors. Setting Two outpatient anticoagulation clinics. Participants A total of 1498 anticoagulated patients. Outcomes Warfarin dose (mg/day), PTTR, major hemorrhage. Results Of the 1498 patients, 22.8% were young, 44.1% were middle aged, and 33.1% were elderly. After accounting for clinical and genetic factors, compared with young warfarin users, warfarin dose requirements were 10.6% lower among the middle aged and an additional 10.6% lower for the elderly. Compared with young patients, middle-aged and elderly patients spent more time in target international normalized ratio (INR) range (p<0.0001), despite having fewer INR assessments (p<0.0001). Compared with young warfarin users, absolute risk of hemorrhage was marginally higher among the middle aged (p=0.08) and significantly higher among the elderly (p=0.016). Compared with young warfarin users, after adjustment, the relative risk of hemorrhage increased by 31% for each age category (p=0.026). Conclusions In a real-world setting, despite achieving better anticoagulation control, elderly patients had a higher risk of major hemorrhagic events. As the population ages and the candidacy for oral anticoagulation increases, strategies that mitigate the elevated risk of hemorrhage need to be identified. | en_US |
dc.eprint.version | Author's manuscript | en_US |
dc.identifier.citation | Shendre, A., Parmar, G. M., Dillon, C., Beasley, T. M. and Limdi, N. A. (2018), Influence of age on warfarin dose, anticoagulation control, and risk of hemorrhage. Pharmacotherapy. Accepted Author Manuscript. http://dx.doi.org/10.1002/phar.2089 | en_US |
dc.identifier.uri | https://hdl.handle.net/1805/15386 | |
dc.language.iso | en | en_US |
dc.publisher | Wiley | en_US |
dc.relation.isversionof | 10.1002/phar.2089 | en_US |
dc.relation.journal | Pharmacotherapy | en_US |
dc.rights | Publisher Policy | en_US |
dc.source | Author | en_US |
dc.subject | age | en_US |
dc.subject | warfarin dose | en_US |
dc.subject | percent time in target range (PTTR) | en_US |
dc.title | Influence of Age on Warfarin Dose, Anticoagulation Control, and Risk of Hemorrhage | en_US |
dc.type | Article | en_US |