Suchman A L, Griner P F
Ann Intern Med. 1986 Jun;104(6):810-6. doi: 10.7326/0003-4819-104-6-810.
The activated partial thromboplastin time (APTT) and prothrombin time (PT) have three principal uses. In screening for coagulation disorders (or increased risk of postoperative hemorrhage), the tests add no information to the preoperative care of patients without clinical findings indicative of increased bleeding risk. Furthermore, the prevalence of asymptomatic congenital coagulopathies is so low that false-positive test results greatly outnumber true-positive results. Thus, clinicians may use clinical assessment to screen and should reserve coagulation tests to investigate patients with abnormal findings. In evaluating abnormal bleeding, these tests are sufficiently sensitive that if both are negative, further investigation of the coagulation system is obviated. If one or both tests are positive, the pattern of results directs further attention to limited segments of the coagulation sequence. In monitoring anticoagulation therapy, the APTT and PT tests appear to contribute to the safety and effectiveness of heparin and warfarin therapies, respectively.
活化部分凝血活酶时间（APTT）和凝血酶原时间（PT）有三个主要用途。在筛查凝血障碍（或术后出血风险增加）时，对于没有提示出血风险增加临床症状的患者，这些检查对术前护理没有额外帮助。此外，无症状先天性凝血病的患病率很低，以至于假阳性检查结果远多于真阳性结果。因此，临床医生可通过临床评估进行筛查，对于有异常发现的患者才应进行凝血检查以进一步评估。在评估异常出血时，这些检查足够敏感，如果两者均为阴性，则无需进一步检查凝血系统。如果一项或两项检查为阳性，结果模式会将进一步的注意力指向凝血序列的特定部分。在监测抗凝治疗时，APTT和PT检查似乎分别有助于肝素和华法林治疗的安全性和有效性。
