Two distinct rationales ensure the trustworthiness of hearsay evidence admitted under Federal Rule Evidence 803(4), which excepts statements for the purpose of medical diagnosis or treatment. First, a patient has a selfish interest in providing truthful information in order to obtain treatment. Second, a statement is reliable if a medical expert uses it to form a basis for diagnosis or treatment. Professor Mosteller examines how courts have analyzed and applied rule 803(4) in child sexual abuse cases, and concludes that their confusion of the two rationales has resulted in decisions which are theoretically, as well as constitutionally, infirm. He then offers guidance as to when and how rule 803(4) can be applied to achiece more accurate results.
Robert P. Mosteller, Child Sexual Abuse and Statements for the Purpose of Medical Diagnosis or Treatment, 67 North Carolina Law Review 257-294 (1989)