Estimating the Prevalence of Injection Drug Use among Black and White Adults in Large U.S. Metropolitan Areas over Time (1992–2002): Estimation Methods and Prevalence Trends

Abstract

No adequate data exist on patterns of injection drug use (IDU) prevalence over time within racial/ethnic groups in U.S. geographic areas. The absence of such prevalence data limits our understanding of the causes and consequences of IDU and hampers planning efforts for IDU-related interventions. Here, we (1) describe a method of estimating IDU prevalence among non-Hispanic Black and non-Hispanic White adult residents of 95 large U.S. metropolitan statistical areas (MSAs) annually over an 11-year period (1992--2002); (2) validate the resulting prevalence estimates; and (3) document temporal trends in these prevalence estimates. IDU prevalence estimates for Black adults were calculated in several steps: we (1) created estimates of the proportion of injectors who were Black in each MSA and year by analyzing databases documenting injectors' encounters with the healthcare system; (2) multiplied the resulting proportions by previously calculated estimates of the total number of injectors in each MSA and year (Brady et al., 2008); (3) divided the result by the number of Black adults living in each MSA each year; and (4) validated the resulting estimates by correlating them cross-sectionally with theoretically related constructs (Black- and White-specific prevalences of drug-related mortality and of mortality from hepatitis C). We used parallel methods to estimate and validate White IDU prevalence. We analyzed trends in the resulting racial/ethnic-specific IDU prevalence estimates using measures of central tendency and hierarchical linear models (HLM). Black IDU prevalence declined from a median of 279 injectors per 10,000 adults in 1992 to 156 injectors per 10,000 adults in 2002. IDU prevalence for White adults remained relatively flat over time (median values ranged between 86 and 97 injectors per 10,000 adults). HLM analyses described similar trends and suggest that declines in Black IDU prevalence decelerated over time. Both sets of IDU estimates correlated cross-sectionally adequately with validators, suggesting that they have acceptable convergent validity (range for Black IDU prevalence validation: 0.27 < r < 0.61; range for White IDU prevalence: 0.38 < r < 0.80). These data give insight, for the first time, into IDU prevalence trends among Black adults and White adults in large U.S. MSAs. The decline seen here for Black adults may partially explain recent reductions in newly reported cases of IDU-related HIV evident in surveillance data on this population. Declining Black IDU prevalence may have been produced by (1) high AIDS-related mortality rates among Black injectors in the 1990s, rates lowered by the advent of HAART; (2) reduced IDU incidence among Black drug users; and/or (3) MSA-level social processes (e.g., diminishing residential segregation). The stability of IDU prevalence among White adults between 1992 and 2002 may be a function of lower AIDS-related mortality rates in this population; relative stability (and perhaps increases in some MSAs) in initiating IDU among White drug users; and social process...

Estimates of the Population Prevalence of Injection Drug Users among Hispanic Residents of Large US Metropolitan Areas

“…A substantial decline in IDU prevalence was previously observed among African American residents of these MSAs on average during this period, while IDU prevalence among non-Hispanic Whites was little changed. 9,23 The decline in Hispanic IDU prevalence is similar to the decline in overall IDU prevalence during this time period. 8 Mortality from AIDS, overdose, and other causes is likely to have contributed to the reduction in IDU prevalence among Hispanics, just as these causes are likely to have contributed to the reduction in IDU prevalence overall.…”

“…Figure 1 depicts average IDU prevalence among Hispanic residents, compared with previously published data for non-Hispanic Black and non-Hispanic White residents across 1992 192 189 21 1068 133 68, 239 1993 178 178 16 931 110 58, 232 1994 178 184 16 1070 115 61, 217 1995 168 175 11 905 101 53, 222 1996 162 173 11 874 95 51, 208 1997 158 172 9 840 95 49, 198 1998 155 172 8 807 95 47, 191 1999 154 173 9 915 99 51, 182 2000 148 164 7 787 95 45, 181 2001 147 162 8 865 99 49, 168 2002 144 160 6 809 93 45, 165 time. 9 Generally, estimates of Hispanic IDU population prevalence were higher than published estimates for non-Hispanic White residents and lower than published estimates for non-Hispanic Black residents.…”

“…The average annual logged linear decline is −0.070; however, the positive polynomial term (0.0028) indicates a flattening of the slope over time. The (9,266). However, the highest IDU prevalence rates among Hispanic residents tended to be in smaller northeastern MSAs.…”

“…Data on overall IDU prevalence and on IDU prevalence among nonHispanic White and non-Hispanic Black residents aged 15-64 of the 96 largest US metropolitan statistical areas (MSAs) have been published for the 1992-2002 period. 8,9 The current study fills a crucial gap by providing estimates of IDU population prevalence among Hispanic residents aged 15-64 in the same set of MSAs during the same time period. To extend the analysis to more recent years, we also examine change in the estimated proportion of IDUs who were Hispanic from 2002 to 2007.…”

Special Issue: Sexual Acquisition and Transmission of HIV Cooperative Agreement Program (SATHCAP), July 2009

“…The papers by Shoptaw et al 20 and Gorbach et al in this issue 21 are vital for understanding the Los Angeles findings, and like others, they show how HIV/AIDS propagation depends on a complex mix of heterogeneous communities. [22][23] An overarching theory of HIV transmission would be a boonas Kurt Lewin remarked, "There is nothing so practical as good theory" 24 -but until we have one, we should remain wary of making things simpler than possible.…”