POLICYMAKING in the fight against drug abuse should be driven by accurate epidemiologic data. By providing information on patterns and consequences of use and demographics of users, such data can show trends over time and the effectiveness of existing strategies.
None of the existing datasets are flawless, as might be expected for information on illegal activities in a variety of populations. Thus, absolute numbers are less important than what the indexes show when looked at as a whole over prolonged periods.
Kleber HD. Tracking the Cocaine EpidemicThe Drug Abuse Warning Network. JAMA. 1991;266(16):2272-2273. doi:10.1001/jama.1991.03470160104041