偏低的APTT(Active partial thromboplastin time,部份凝血活酶時間)在傳統上被認為是有問題的抽 血技術所造成的假性數據。然而，近年來有證據顯示偏低的APTT反而是反映了人體内為容易凝血的狀 態，可能與增加栓塞機率和不良的心血管事件有關。過去文獻指出一般血凝實驗室APTT偏低的比率約 為6%-9°%，本研究統計個案醫院2014年1月至4月門診、病房和急診室APTT偏低的比例數據，分別為 7.8°%、8.3°%和22.4°%，經過探討急診室比率較高的原因是因為抽血流程問題造成，並非是因為容易凝血 狀態之病人較多。透過文獻查證以及跨部門團隊合作運用品管圏手法制訂改善策略，採取措施包括：使 用真空抽血設備、將APTT藍頭抽血管直立擺放、製作提醒小卡提示採血管要上下混合、制定抽血標準 作業流程和在職教育訓練。最後，急診室APTT偏低比率有明顯的改善，由原本改善前的24.3%下降至 15.9%。

Short activated partial thromboplastin times (APTTs) are generally considered to be a surrogate marker of inappropriate blood collections. However, recent evidence suggests that short APTT may reflect a hypercoagulable state, potentially associated with an increased thrombotic risk and adverse cardiovascular events. Earlier studies have showed the proportion of short APTT is about 6%-9% in the hemostasis laboratory. We prospectively computed the rate of short APTT in outpatient, inpatient and emergency (ER) from January to April, 2014, and the proportion were 7.8%, 8.3% and 22.4%, respectively. We assumed that higher proportion in ER might be due to the inappropriate blood collections not more patients in a hypercoagulable state. Through a literature review and in accordance with the improvement strategy, the following methods were taken: using vacuum extraction tube systems, putting sodium citrate tube upright, reminding cards for overturning the blood collection tube, creation of standard operating procedures, in-service training. In conclusion, there was a significant reduction in the proportion of short APTT in ER with a reduction from 24.3% to 15.9%.