Age-adjusted rates* for drug overdose deaths, by sex and residential area† — National Vital Statistics System, United States, 1999–2015
* Death rates per 100,000 persons were adjusted to the 2000 U.S. standard population by the direct method.
† Uses the National Center for Health Statistics six classification levels for counties: 1) large central metropolitan: part of a metropolitan statistical area with ≥1 million population and covers a principal city; 2) large fringe metropolitan: part of a metropolitan statistical area with ≥1 million population but does not cover a principal city; 3) medium metropolitan: part of a metropolitan statistical area with ≥250,000 but <1 million population; 4) small metropolitan: part of a metropolitan statistical area with <250,000 population; 5) micropolitan (nonmetropolitan): part of a micropolitan statistical area (has an urban cluster of ≥10,000 but <50,000 population); and 6) non-core (nonmetropolitan): not part of a metropolitan or micropolitan statistical area.