Figure 2.

The temporal diagram showing historical electronical health record (EHR) data up to 2 years prior to an index visit at an emergency department or an inpatient facility. A case index visit represents a first-time suicide attempt visit and a control index visit represents a randomly selected visit from controls with longitudinal EHR data. A first-time suicide attempt visit ($V_{t_0}$) is defined as first known suicide attempt visit between 2005 and 2016; $V_{t_0}$: the index visit; $V_{t_{-1}}$: last point of clinical contact or last clinical encounter prior to the index visit ($V_{t_0}$). A prediction window is defined as the time interval between the index visit time ($V_{t_0}$) and the historical most recent clinical-visit time ($V_{t_{-1}}$) prior to the index visit.