Diagnostic codes associated with hypnotic medications during outpatient physician-patient encounters in the United States from 1990-1998

Study Objectives: This investigation tabulates the most common diagnostic codes associated with use of hypnotic medications during physician-patient encounters in the U.S. Design: Estimates were derived from the National Ambulatory Medical Care Survey (NAMCS) from 1990 through 1998. Diagnoses were coded according to the International Classification of Disease-Clinical Modification-9th Edition (ICD-9-CM). Setting: The NAMCS collects outpatient visit data from nonfederal physicians of all specialties, except anesthesiology, pathology, and radiology. Participants: N/A Interventions: N/A Measurements and Results: Hypnotic medications were more commonly associated with psychiatric codes than with the symptom of insomnia. Primary insomnia did not appear among the codes most commonly associated with a hypnotic prescription. Conclusions: Hypnotics were more commonly associated with psychiatric codes than with insomnia codes, but it is unknown whether the coding accurately reflects the true diagnoses. Still; since there is minimal data on the efficacy and safety of hypnotics in persons with psychiatric disorders, these findings may signal a critical knowledge gap in the treatment of insomnia.