The Narcotics Register Project of the New York City Department of Health was established in 1966 in response to the growing concern over the problem of narcotics addiction in New York City. The Narcotics Register has been developed, like other case registers, as a system for collecting information of a narcotic-addicted population based on cases reported by various agencies. These agencies include hospitals, addiction services, police and correctional institutions, private medical practitioners, and other health and social services programs