Trends in the Population Prevalence of People Who Inject Drugs in US Metropolitan Areas 1992–2007

Abstract

BackgroundPeople who inject drugs (PWID) have increased risk of morbidity and mortality. We update and present estimates and trends of the prevalence of current PWID and PWID subpopulations in 96 US metropolitan statistical areas (MSAs) for 1992–2007. Current estimates of PWID and PWID subpopulations will help target services and help to understand long-term health trends among PWID populations.MethodologyWe calculated the number of PWID in the US annually from 1992–2007 and apportioned estimates to MSAs using multiplier methods. We used four types of data indicating drug injection to allocate national annual totals to MSAs, creating four distinct series of component estimates of PWID in each MSA and year. The four component estimates are averaged to create the best estimate of PWID for each MSA and year. We estimated PWID prevalence rates for three subpopulations defined by gender, age, and race/ethnicity. We evaluated trends using multi-level polynomial models.ResultsPWID per 10,000 persons aged 15–64 years varied across MSAs from 31 to 345 in 1992 (median 104.4) to 34 to 324 in 2007 (median 91.5). Trend analysis indicates that this rate declined during the early period and then was relatively stable in 2002–2007. Overall prevalence rates for non-Hispanic black PWID increased in 2005 as compared to other racial/ethnic groups. Hispanic prevalence, in contrast, declined across time. Importantly, results show a worrisome trend in young PWID prevalence since HAART was initiated – the mean prevalence was 90 to 100 per 10,000 youth in 1992–1996, but increased to >120 PWID per 10,000 youth in 2006–2007.ConclusionsOverall, PWID rates remained constant since 2002, but increased for two subpopulations: non-Hispanic black PWID and young PWID. Estimates of PWID are important for planning and evaluating public health programs to reduce harm among PWID and for understanding related trends in social and health outcomes.

Population Size Estimates for Men who Have Sex with Men and Persons who Inject Drugs

“…[6][7][8] These estimates are extremely useful for studies that are nationwide or are conducted in specific metropolitan areas, but they do not allow for aggregation of data across sub-national areas that also contain small cities or nonmetropolitan areas. We are not aware of published estimates of the overall prevalence of injection drug use by urbanicity, although estimates for prevalence of injection drug use by region and estimates for injection of specific drugs by urbanicity have been published.…”

HIV Infection and HIV-Associated Behaviors Among Persons Who Inject Drugs — 20 Cities, United States, 2015

“…All comparisons were considered significant if there was no overlap in their adjusted 95% CIs; because of the sampling methodology, RDS analysis is limited to calculating point estimates with CIs and precludes any other statistical testing. A weighted average of MSA-level estimates was calculated using the estimated size of the population of persons who inject drugs in each MSA to describe aggregated prevalence of HIV and percentage of participants engaging in selected behaviors ( 7 ). §§§ …”

Female and male differences in AIDS diagnosis rates among people who inject drugs in large U.S. metro areas from 1993 to 2007

“…For each MSA, period and gender, we calculated IARs by dividing the total number of AIDS diagnoses during that period by the estimated number of male or female PWID without AIDS. Methods for creating annual estimates of PWID for each MSA for females and males have been reported in detail elsewhere, but involve calculating the number of PWID in the US and then apportioning estimates to MSAs using multiplier methods [3, 11–13]. These estimates were based on data on HIV counseling and testing, drug treatment, AIDS diagnoses, and estimates from published national and MSA-specific research studies [3, 13].…”

“…In 2011, 20% of new AIDS diagnoses among females were injection-related, while only 10% of AIDS diagnoses among males were from PWID [1]. During this time, we have estimated that PWID prevalence per 10,000 adult population in large US metropolitan statistical areas (MSAs) also fell from 157 in 1993–1995 to 133 in 2005–2007 among males, and from 82 to 75 among females [3]. These data raise questions about changes in epidemiological patterns of AIDS among female PWID and how these patterns may vary across geographic areas.…”