Petitti D B, Strom B L, Melmon K L
Division of Research, Kaiser Permanente Medical Care Program, Oakland, California.
J Clin Epidemiol. 1989;42(8):759-64. doi: 10.1016/0895-4356(89)90073-5.
We previously showed that the risk of major hemorrhage in patients with venous thromboembolism treated with warfarin was strongly related to duration of anticoagulant therapy. We here report the results of a more detailed analysis of factors other than duration of warfarin therapy associated with the risk of hemorrhage in these patients. Almost 7% of patients had a major hemorrhage on warfarin and an additional 23.7% had at least one minor bleeding episode. Age, female sex, and congestive heart failure were associated with small increases in the risk of major hemorrhage but not with the risk of minor bleeding. A prothrombin time ratio greater than 2.5 was associated with a fourteen-fold increase in the risk of a major hemorrhage (95% CI 5.1, 42.7), but major hemorrhages occurred in patients on warfarin at all measured values of the prothrombin time ratio. Taken together with the findings from our previous analysis, the study suggests that prevention of bleeding in patients on warfarin would best be accomplished by minimizing the duration of warfarin therapy, by scrupulous monitoring of the prothrombin time ratio, and by considering the "therapeutic range" for the prothrombin time ratio to be somewhat less than 2.0-2.5.
我们之前表明，接受华法林治疗的静脉血栓栓塞患者发生大出血的风险与抗凝治疗的持续时间密切相关。我们在此报告对这些患者中除华法林治疗持续时间外与出血风险相关的其他因素进行更详细分析的结果。近7%的患者在服用华法林期间发生了大出血，另有23.7%的患者至少发生过一次轻微出血事件。年龄、女性性别和充血性心力衰竭与大出血风险的小幅增加相关，但与轻微出血风险无关。凝血酶原时间比值大于2.5与大出血风险增加14倍相关（95%置信区间5.1, 42.7），但在所有测量的凝血酶原时间比值下，服用华法林的患者中均发生了大出血。结合我们之前分析的结果，该研究表明，预防服用华法林患者出血的最佳方法是尽量缩短华法林治疗的持续时间，严格监测凝血酶原时间比值，并考虑将凝血酶原时间比值的“治疗范围”设定为略低于2.0 - 2.5。
