Should ER studies, and the risk estimates derived from them, switch to BAC rather than self-report as the main source of estimation of alcohol consumed? The main problem with this, as has been noted in these studies, is the substantial number of cases who reported drinking but show a zero BAC, presumably because their body had already metabolized drinks they had in fact consumed (and not due to a bogus pipeline effect). Over one-quarter (26.2%, Table 2) of those reporting some drinking showed a zero BAC, while only 2.1% of those who reported no drinking had a positive BAC.
