Discordance between patient preferences for end-of-life care and documentation of their wishes is a common problem in hospitals. Such events have been described as silent misdiagnoses and may be classified as medical errors. This audit study across 16 hospitals in Canada quantified how often medical orders for life-sustaining treatments do not match patient preferences. Only 2% of patients who reported a preference for cardiopulmonary resuscitation (CPR) had CPR withheld in their medical orders; whereas, 35% of patients who wished to forgo CPR had orders to receive it in the event of an arrest. This mismatch represents a considerable source of potential overtreatment, which may result in numerous adverse downstream effects. A previous WebM&M commentary discussed tools for eliciting end-of-life preferences.