Center for Health Quality, Outcomes and Economic Research, Bedford VA Medical Center, Bedford, MA 01730, USA.
J Thromb Haemost. 2012 Apr;10(4):590-5. doi: 10.1111/j.1538-7836.2012.04649.x.
Not all clinicians target the same International Normalized Ratio (INR) for patients with a guideline-recommended target range of 2-3. A patient's mean INR value suggests the INR that was actually targeted. We hypothesized that sites would vary by mean INR, and that sites of care with mean values nearest to 2.5 would achieve better anticoagulation control, as measured by per cent time in therapeutic range (TTR).
To examine variations among sites in mean INR and the relationship with anticoagulation control in an integrated system of care.
PATIENTS/METHODS: We studied 103,897 patients receiving oral anticoagulation with an expected INR target between 2 and 3 at 100 Veterans Health Administration (VA) sites from 1 October 2006 to 30 September 2008. Key site-level variables were: proportion near 2.5 (that is, percentage of patients with mean INR between 2.3 and 2.7) and mean risk-adjusted TTR.
Site mean INR ranged from 2.22 to 2.89; proportion near 2.5, from 30 to 64%. Sites' proportions of patients near 2.5, below 2.3 and above 2.7 were consistent from year to year. A 10 percentage point increase in the proportion near 2.5 predicted a 3.8 percentage point increase in risk-adjusted TTR (P < 0.001).
Proportion of patients with mean INR near 2.5 is a site-level 'signature' of care and an implicit measure of targeted INR. This proportion varies by site and is strongly associated with site-level TTR. Our study suggests that sites wishing to improve TTR, and thereby improve patient outcomes, should avoid the explicit or implicit pursuit of non-standard INR targets.
并非所有临床医生都将患者的国际标准化比值（INR）设定在指南推荐的 2-3 范围内。患者的平均 INR 值表明了实际的目标 INR 值。我们假设各中心的平均 INR 值会有所不同，而接近 2.5 的平均 INR 值的治疗中心将能更好地控制抗凝效果，其衡量标准是治疗范围内时间的百分比（TTR）。
在一个综合性医疗体系中，研究各中心之间平均 INR 的差异及其与抗凝控制之间的关系。
患者/方法：我们研究了 2006 年 10 月 1 日至 2008 年 9 月 30 日期间，103897 名在 100 个退伍军人事务部（VA）医疗中心接受 INR 目标值在 2-3 之间的口服抗凝治疗的患者。关键的中心层面变量包括：接近 2.5 的比例（即平均 INR 在 2.3-2.7 之间的患者百分比）和平均风险调整 TTR。
中心平均 INR 值范围为 2.22-2.89；接近 2.5 的比例为 30%-64%。各中心接近 2.5 的患者比例、低于 2.3 和高于 2.7 的比例在逐年保持一致。接近 2.5 的患者比例每增加 10%，风险调整 TTR 就会增加 3.8%（P<0.001）。
接近 2.5 的平均 INR 患者比例是一种中心层面的“特征”，也是目标 INR 的隐含衡量标准。该比例因中心而异，与中心层面的 TTR 密切相关。我们的研究表明，希望提高 TTR 从而改善患者预后的中心应避免明确或隐含地追求非标准 INR 目标。
