首先看一下SDTM_IG（Study Data Tabulation Model Implementation Guide）中關(guān)于Domain EG的介紹：
Findings related to the collection of ECG data, including position of the subject, method of evaluation, all cycle measurements and all findings from the ECG including an overall interpretation if collected or derived.
簡(jiǎn)單看顽悼，Domain EG是關(guān)于ECG的數(shù)據(jù)信息的。這次只介紹EGBLFL的編程細(xì)節(jié)。先看IG中的介紹：Baseline Flag铲球，Indicator used to identify a baseline value. The value should be “Y” or null. 這一變量是用來標(biāo)記受試者的基線值殿遂。什么為基線叹洲？基線是臨床試驗(yàn)開始前受試者觀察指標(biāo)的測(cè)量值情臭。如果在臨床試驗(yàn)開始前点晴，有多個(gè)測(cè)量值霍掺，取時(shí)間距臨床試驗(yàn)開始最近的測(cè)量值作為基線值匾荆。編程流程有兩個(gè)要點(diǎn)：1）“臨床試驗(yàn)開始”拌蜘；2）“時(shí)間最近”。
接下來列舉一些項(xiàng)目牙丽，Spec中 EGBLFL 的生成要求：
- Latest non missing measurement (EGDTC if EGSTRESC is not missing) on or before first dose date(DM.RFSTDTC) then set to 'Y', otherwise set to missing
- For quantitative EGTESTCD and EGTESTCD='INTP', use Implementation Notes to derive EGBLFL.For other qualitative EGTESTCD, merge derived EGBLFL to each QSTESTCD via EGDTC. For EGTESTCD='EGCOM', call missing EGBLFL.
- The latest record on or prior to the date of initial dose is flagged as the baseline. i.e. assign xxBLFL as "Y". Else null. If time is not available the last observed measurement on or before the date of initial dose will be considered the baseline measurement. If date and time are available the last observed measurement on or before the date and time of initial dose will be considered the baseline measurement.
從這上面看简卧，“臨床試驗(yàn)開始”有定義為RFSTDTC（Subject Reference
Start Date/Time），又定義為“the date of initial dose”烤芦。我們來看一下RFSTDTC的解釋：Reference Start Date/time for the subject in ISO 8601 character format. Usually equivalent to date/time when subject was first exposed to study treatment. 也就是說举娩，這兩個(gè)時(shí)間通常是一樣的。
