Center for Healthcare Organization and Implementation Research, Bedford VA Medical Center, Bedford, MA, USA; Department of Medicine, Section of General Internal Medicine, Boston University School of Medicine, Boston, MA, USA.
J Thromb Haemost. 2014 May;12(5):628-34. doi: 10.1111/jth.12530.
While a considerable amount is known about which patient-level factors predict poor anticoagulation control with warfarin, measured by percent time in therapeutic range (TTR), less is known about predictors of time above or below target.
To identify predictors of different patterns of international normalized ratio (INR) values that account for poor control, including 'erratic' patterns, where more time is spent both above and below INR target, and unidirectional patterns, where time out of range is predominantly in one direction (low or high).
We studied 103 897 patients receiving warfarin with a target INR of 2-3 from 100 Veterans Health Administration sites between October 2006 and September 2008. Our outcomes were percent time above and below the target range. Predictors included patients' demographics, comorbidities, and other clinical data.
Predictors of erratic patterns included alcohol abuse (5.2% more time below and 3.7% more time above, P < 0.001 for all results), taking > 16 medications (4.6% more time below and 1.8% more time above compared to taking seven or fewer medications), and four or more hospitalizations during the study (6.6% more time below and 2% more time above compared to no hospitalization). In contrast, predictors like cancer, non-alcohol drug abuse, dementia, and bipolar disorder were associated with more time below the target range (3.4%, 5.2%, 2.6%, and 3.2%, respectively) and less (or similar) time above range.
Different patient-level factors predicted unidirectional below-target and 'erratic' patterns of INR control. Distinct interventions are necessary to address these two separate pathways to poor anticoagulation.
尽管已经了解了许多与华法林抗凝治疗控制不佳（以治疗范围内时间百分比[TTR]衡量）相关的患者水平因素，但对于高于或低于目标时间的预测因素了解较少。
确定不同国际标准化比值（INR）值模式的预测因素，这些模式可解释控制不佳的原因，包括“不规则”模式，即更多时间处于 INR 目标值上下；以及单向模式，即超出目标范围的时间主要在一个方向（高或低）。
我们研究了 2006 年 10 月至 2008 年 9 月期间，来自 100 个退伍军人健康管理局站点的 103897 名接受华法林治疗且 INR 目标值为 2-3 的患者。我们的结局是高于和低于目标范围的时间百分比。预测因素包括患者的人口统计学特征、合并症和其他临床数据。
不规则模式的预测因素包括酒精滥用（低于目标的时间多 5.2%，高于目标的时间多 3.7%，所有结果均 P<0.001）、服用>16 种药物（低于目标的时间多 4.6%，高于目标的时间多 1.8%，而服用 7 种或更少药物）和研究期间住院 4 次或以上（低于目标的时间多 6.6%，高于目标的时间多 2%，而无住院）。相比之下，癌症、非酒精药物滥用、痴呆和双相情感障碍等预测因素与低于目标范围的时间更长（分别为 3.4%、5.2%、2.6%和 3.2%）和高于目标范围的时间更短（或相似）相关。
不同的患者水平因素预测了 INR 控制的单向低于目标和“不规则”模式。需要采取不同的干预措施来解决这两种不同的抗凝不良途径。
