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

when they were begun in 1984, and approximately 600 men continue to
participate semiannually in this, the tenth year of the study. NMPD use
patterns have been analyzed for all men attending at each semiannual
assessment and also for the smaller number of men (approximately 350)
who have participated every year since the start of the study. Since there
were no significant differences between the serial cross-sectional and
panel patterns for commonly used substances, the former are presented
here.
PATTERNS OF NMPD USE IN A COHORT OF GAY AND
BISEXUAL MEN
Table 1 illustrates the long-term patterns (1984-1993) of use of those
continuously monitored NMPDs and cigarette smoking in the Chicago
MACS/CCS cohort, while table 2 shows the alcohol consumption
patterns for that same period. While frequency of use in the past
6 months was assessed for nine classes of drugs at each semiannual visit,
prevalence patterns suggest three general categories of NMPD use by
members of the Chicago MACS/CCS cohort seen at each semiannual
evaluation.
Frequently Used NMPDs
The prevalence rates for use of marijuana and volatile nitrates (poppers)
are extremely similar, and are the highest of any of the classes of
recreational substances throughout the study period (table 1). There was
a gradual decline during the first 3 years of the study, from approximately
70 percent of participants using either substance in 1984 to less than 50
percent reporting use from 1986 onward, but little reported change in
popularity since visit 6 or 7. At the start of the study, over 60 percent of
men reported using both marijuana and poppers; this proportion declined
to approximately 35 percent by visit 12. This drop in use of both
marijuana and poppers corresponded with a drop in the average number
of NMPDs used, from two to one (figure 1). From visits 12 to 16 there
was a further drop in popper use (to 20 percent), but a more recent
rebound (visits 17 to 19) to approximately one-third is evident in the
latest data. Cocaine was the third most popular NMPD used throughout
the study, decreasing from a prevalence of one-third of the cohort at the
study’s beginning to one-sixth from visits 6 to 7 onward. Cocaine use
was almost exclusively through nasal insufflation: Crack cocaine use was
only specifically assessed beginning with visit 12 and was reported by
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