The use of external data sources and ratio estimation to improve estimates of hardcore drug use from the NHSDA.

Levels of hardcore drug use have been especially difficult to estimate because of the relative rarity of the behavior, the difficulty of locating hardcore drug users, and the tendency to underreport stigmatized behavior. This chapter presents a new application of ratio estimation, combining sample data from the National Household Survey on Drug Abuse (NHSDA) together with population counts of the number of persons arrested in the past year from the Uniform Crime Report (UCR) and the number of persons in drug treatment programs in the past year from the National Drug and Alcoholism Treatment Unit Survey (NDATUS). The population counts serve as a benchmark accounting for undercoverage and underreporting of hard drug users.