Most ambulance providers who service Medicare patients are trained in Advanced Life Support (ALS), but studies have begun to suggest that ALS is actually harmful to those who receive it. A 2015 study by CHAS Fellow and Medicaid Working Group investigator, Prachi Sanghavi and colleagues reveals that 90-day survival rates among patients with trauma, stroke, and respiratory failure was lower among those who had receives ALS than those who had received its Basic counterpart (BLS). The researchers therefore concluded that ALS is associated with higher mortality for several acute medical emergencies than BLS.