Table 1 presents the drug abuse histories reported by cases from UHS and the GAIN replication cohort. Among the 3,159 UHS drug abuse cases, the majority (63.4%) reported abusing heroin/opioids 10 or more times in the past 30 days; on average, they used heroin/opioids 80.9 times over the past 30-day period, indicating their high-degree of abuse. The remainder of the UHS cases reported past 30-day abuse of cocaine, marijuana, or amphetamine/stimulants or abuse of other drugs. Nearly one-third of the UHS cases reported abusing more than one drug in the past 30 days. Among the cases from GAIN, a higher percentage abused more than one drug, as expected, given that abuse was based on lifetime history here compared to past 30 days in UHS. Marijuana was the most frequently reported drug abuse in GAIN.
