Schmitt L, Speckman J, Ansell J
Departments of Medicine & Pharmacy, Boston University Medical Center, 88 East Newton Street, Boston, MA 02118, USA.
J Thromb Thrombolysis. 2003 Jun;15(3):213-6. doi: 10.1023/B:THRO.0000011377.78585.63.
The results of clinical trials often hinge on the quality of oral anticoagulation management, yet the quality of such management is frequently not mentioned or measured. Time-in-therapeutic range (TTR) is one measure of quality of anticoagulation dose management, but various methodologies exist for measuring TTR.
This study was initiated to compare three commonly used methodologies for measuring TTR to see how they compare within the same cohort of patients.
PATIENTS/METHODS: Three common methodologies of calculating time-in-therapeutic range were analyzed retrospectively in a cohort of patients over six two-month intervals. Additional analysis was performed for three and six-month intervals. The methodologies included fraction of INRs in range; cross-section of the files; and linear interpolation.
Fraction of the INRs in range and cross-section of the files methodologies gave similar results, while linear interpolation yielded significantly shorter time-in-range for the two-month, three-month, and six-month intervals measured. The advantages and disadvantages of each methodology are discussed.
The decision of which method to use should be based on clinic size, information desired, and clinic resources for ease of applying either of the methods in clinical practice. Each of these methodologies has their limitations and the question remains as to which method best reflects the quality of anticoagulation management. Regardless of these limitations, investigators are urged to employ at least one method of measuring the quality of oral anticoagulation management so as to better assess the validity of the clinical outcomes.
临床试验结果常常取决于口服抗凝管理的质量，但这种管理的质量常常未被提及或衡量。治疗范围内时间（TTR）是抗凝剂量管理质量的一种衡量指标，但存在多种测量TTR的方法。
开展本研究以比较三种常用的测量TTR的方法，看看它们在同一组患者中的比较情况。
患者/方法：回顾性分析了一组患者在六个为期两个月的时间段内计算治疗范围内时间的三种常用方法。还对三个月和六个月的时间段进行了额外分析。这些方法包括范围内国际标准化比值（INR）的比例；病历横断面；以及线性插值法。
范围内INR的比例法和病历横断面法得出的结果相似，而线性插值法在测量的两个月、三个月和六个月时间段内得出的治疗范围内时间明显更短。讨论了每种方法的优缺点。
使用哪种方法的决定应基于诊所规模、所需信息以及诊所资源，以便于在临床实践中应用这两种方法中的任何一种。这些方法都有其局限性，哪种方法最能反映抗凝管理质量的问题仍然存在。尽管有这些局限性，但仍敦促研究人员采用至少一种测量口服抗凝管理质量的方法，以便更好地评估临床结果的有效性。
