The Context of HIV Risk Among Drug Users and Their Sexual Partners

less than 2 percent of participants at that time. The legal but highly
psychoactive substance, nicotine, was reported consumed through
cigarette smoking by about one-third of the participants throughout the
study (table 1).
Infrequently Used Substances
All of the other NMPDs inquired about were used by less than 20 percent
of the participants at the start of the study and declined by at least
three-quarters to less than 5 percent by visit 6 (table 1). Reported use of
downers (mostly methaqualone and barbiturates) and the hallucinogen
1-(3,4-methylenedioxyphenyl)-2-aminopropane (MDA) have continued
to decline to less than 2 percent of participants in recent visits. Smoked
cocaine, or crack, was only assessed beginning with the 12th visit, and
use was less than 2 percent prevalent at that time.
The differentially greater decreases in the proportion of men using the
less popular NMPDs probably reflects their use by a subgroup of men
using three or more drugs and at significantly higher risk of prevalent
HIV infection, a group that has differentially dropped out of the study
over time. Men who regularly and consistently participate in the Chicago
MACS/CCS studies are significantly less likely to be HIV infected
(25-30 percent versus 50-60 percent HIV antibody prevalence rates
among the two groups) and use fewer NMPDs than the men who have
dropped out or been inconsistent in their study participation. In addition,
men developing AIDS in the course of their study participation have
either dropped out or been excluded from further behavioral assessment.
Given the significantly higher HIV infection rates among polysubstanceusing
men of the MACS (Chmiel et al. 1987; and Easterbrook et al. 1993;
Ostrow et al. 1987), the dramatic decline in popularity of uppers,
downers, and hallucinogenic drugs seen in the study cohort may reflect
the rapid increase in AIDS and related deaths among members of the fast
track subpopulation of Chicago’s gay community between 1984 and
1987. Both of these general patterns suggest that results based on
long-term and consistent participants in the Chicago MACS/CCS may
underestimate the actual rate of current NMPD use among the original
cohort members and lessen the likelihood of detecting the relationships
between NMPD use and sexual behavior patterns.
92