While the term “treatment” has a prospective focus, the term “diagnosis” does not. – Opinion. After an ER visit, Patient was left brain dead. Afterwards, his roommate asked a doctor if past cocaine use could have been a cause. At trial, roommate’s statement to the doctor was the focus of the defense case. The trial court admitted the evidence and doctors won. The court of appeals held the admission of drug-use evidence was error. The Court disagreed, holding that CRE 803(4), the medical diagnosis or treatment hearsay exception, applied. Statements offered to determine the nature, source or cause of a condition, which also describe medical history and are pertinent to the diagnosis, are excepted, as in this case. No further inquiry into roommate’s motives was required, nor was subjective reliance by the doctor. And, though prejudicial, the statements were not unfair. Doctors win.