- 學位論文
不同PT/INR危急值警示系統與warfarin使用安全性之評估
Impact of Personal Handy-phone System (PHS) Reminder System on Practitioner Performance and Patient Outcomes in Warfarin Users
摘要
華法林 (warfarin) 是一種常見的的口服抗凝血劑，用來預防及治療與凝血機制相關疾病。而此藥的療效是不容易被控制，會受很多干擾因子影響，像病患本身的體質、飲食習慣、同時併用的藥物等等，都會使得華法林的療效不穩定。過多的劑量會增加發生出血併發症的危險，過少的劑量則有可能會導致栓塞。因此醫生抽血檢驗凝血酶原時間 (PT) ，來監測華法林的藥效，確保病人的療效是在安全範圍之內。為了使各地醫院治療目標一致，將凝血酶原時間轉換為國際標準化比值 (INR) ，一般認為白種人的華法林療效範圍約在INR值2-3之間，但是對於亞洲人而言，較低劑量是相對比較安全的，出現嚴重的併發症的比例較低。 我們擷取在2006年1月1日至2008年12月31日間，曾在台大醫院門診服用華法林的病患資料。全部共有4794位病患被納入分析，他們的平均INR值為2.00 ± 1.20，出血及栓塞事件的發生率為每病人年6.1%。 臺大醫院檢驗醫學部設有危急值警示系統，用來監測INR值是否超過安全值，當PT > 50時，則檢驗醫學部人員會打電話通知醫生，告知有病患的INR值超過安全範圍。檢驗醫學部在2007年5月17日建立PHS危急值警示系統，改用傳簡訊的方式通知醫生，取代原有的打電話方式。我們將2006年1月1日至2007年5月16日訂為人工通報時期，而將PHS通報時期訂為2007年9月1日至2008年12月31日。利用兩個時期的比較，我們評估改用PHS危急值警示系統之後，華法林的併發症發生率是否有升高，和醫生對於通報處理的比較。我們考慮了併發症發生率與季節相關，將兩組的追蹤時段各取一『日曆年』來做比較，另外也對於不同科別及醫生年資分別做探討。我們的結果顯示，醫生對於危急值的處理，和病人的出血及栓塞事件發生率，並沒有因改為PHS危急值警示系統而改變，甚至對於資深醫師醫療行為有提升的作用。 根據我們的研究，台灣病患服用華法林的劑量不宜太高。另外，在監測華法林的療效上，傳簡訊通知醫師的效果與打電話告知差異不大，病人發生併發症情況及醫師的醫療行為在二種警示系統上並沒有明顯改變；對於資深醫師，傳簡訊的方式較能增進醫療的品質。所以，PHS危急值警示系統是適合用在實驗室危急值的通報上。
並列摘要
Warfarin is a common oral anticoagulant that prescribed for the management of thromboembolic disorders. It has narrow therapeutic range, and its therapeutic effect was varied due to multiple factors such as a patient’s physical condition, diet habits, and concurrently used medicines etc. Higher dosage of warfarin may increase the risk of bleeding, but lower dosage may lead to thromboembolism. Therefore, clinicians monitored warfarin effect with prothrombin time (PT) tests and standardized international normalized ratio (INR) to ensure patients’ safety and effectiveness. In general, a recommendation of a therapeutic INR value of 2 to 3 was made for most indications for Caucasians, but a lower dosage of warfarin treatment might be appropriate for Asians. We included relevant records of outpatients receiving warfarin at National Taiwan University Hospital (NTUH) from January1st, 2006 to December 31st, 2008. In this study, a total of 4794 outpatients were included, and the mean INR values of them were 2.00 ± 1.20. The incidence rate of adverse drug events was 6.1% per patient-year. A PHS alert system for high PT/INR threshold values (PT > 50 seconds) has been established since May 17th, 2007 in NTUH. We defined January 1st, 2006 to May 16th, 2007 as the manual reminders period, and starting from September 1st, 2007 to December 31st, 2008 as the PHS alert system period. We assessed the impact of the new PHS alert system by comparing practitioner performance and patient outcomes between manual reminders and PHS periods. Adverse drug events in one calendar year were also analyzed between 2 groups considering seasonal effect. Physician specialty and seniority were took into account when practitioner performance was evaluated. Lower dosage of warfarin treatment might be considered as appropriate for patients in Taiwan. A switch to PHS alert system from manual reminders did not compromise patient outcomes and clinician performance, and indeed improved quality of care in senior physicians. PHS alert system was promising as a reminder of laboratory alert values to clinicians.