title: Methods of studying prevalence and incidence of drug abuse.
mesh_terms: D002921:Cicatrix; D011307:Drug Prescriptions; D004363:Drug Utilization; D004335:Drug and Narcotic Control; D004812:Epidemiologic Methods; D006801:Humans; D007267:Injections; D012042:Registries; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000401:mortality; D011795:Surveys and Questionnaires; D013548:Sweden