Reduction in Needle Sharing Among Seattle-Area Injection Drug Users Across 4 Surveys, 1994-2013.

Objectives: We evaluated time trends in sharing needles and other injection equipment from 1994 to 2013 among injection drug users in the Seattle, Washington area.

Methods: We combined data from 4 sources: the Risk Activity Variables, Epidemiology, and Network (RAVEN) study, recruited from institutional settings; the Kiwi study, recruited from jails; National HIV Behavioral Surveillance system (NHBS) surveys, which used respondent-driven sampling; and surveys at needle-exchange sites.

Results: Levels of needle sharing were higher in the earlier studies: RAVEN, 1994 to 1997 (43%) and Kiwi, 1998 to 2002 (61%).

Assessing differences in groups randomized by recruitment chain in a respondent-driven sample of Seattle-area injection drug users.

Purpose: Respondent-driven sampling (RDS) is a form of peer-based study recruitment and analysis that incorporates features designed to limit and adjust for biases in traditional snowball sampling. It is being widely used in studies of hidden populations. We report an empirical evaluation of RDS's consistency and variability, comparing groups recruited contemporaneously, by identical methods and using identical survey instruments.

Unmet health care needs and hepatitis C infection among persons who inject drugs in Denver and Seattle, 2009.

Persons who inject drugs (PWID) shoulder the greater part of the hepatitis C virus (HCV) epidemic in the USA. PWID are also disproportionately affected by limited access to health care and preventative services. We sought to compare current health care coverage, HCV, and HIV testing history, hepatitis A and B vaccination coverage, and co-occurring substance use among PWID in two US cities with similar estimated numbers of PWID.

Evidence for risk reduction among amphetamine-injecting men who have sex with men; results from national HIV behavioral surveillance surveys in the Seattle area 2008-2012.

In the Seattle area men who have sex with men and also inject amphetamines (amphetamine-injecting MSM/IDU) are disproportionately likely to be infected with HIV. To characterize their distinctive characteristics, we combined data from two Seattle-area surveys of men who have sex with men (MSM) and two surveys of injection drug users (IDU). Amphetamine-injecting MSM/IDU were compared with: male IDU, MSM and other MSM/IDU.

"To share or not to share?" Serosorting by hepatitis C status in the sharing of drug injection equipment among NHBS-IDU2 participants.

Background: Persons who inject drugs (PWID) are at high risk for acquiring hepatitis C virus (HCV) infection. The Centers for Disease Control and Prevention estimates there are 17 000 new infections per year, mainly among PWID. This study examines injection equipment serosorting-considering HCV serostatus when deciding whether and with whom to share injection equipment.

Comparing study populations of men who have sex with men: evaluating consistency within repeat studies and across studies in the Seattle area using different recruitment methodologies.

There is no gold standard for recruiting unbiased samples of men who have sex with men (MSM). To assess differing recruitment methods, we compared Seattle-area MSM samples from: venue-day-time sampling-based National HIV Behavioral Surveillance (NHBS) surveys in 2008 and 2011, random-digit-dialed (RDD) surveys in 2003 and 2006, and STD clinic patient data 2001-2011. We compared sociodemographics, sexual and drug-associated behavior, and HIV status and testing.

Evaluating consistency in repeat surveys of injection drug users recruited by respondent-driven sampling in the Seattle area: results from the NHBS-IDU1 and NHBS-IDU2 surveys.

Purpose: We compared data from two respondent-driven sampling (RDS) surveys of Seattle-area injection drug users (IDU) to evaluate consistency in repeat RDS surveys.

Methods: The RDS-adjusted estimates for 16 key sociodemographic, drug-related, sexual behavior, and HIV- and hepatitis C virus-related variables were compared in the 2005 and the 2009 National HIV Behavioral Surveillance system surveys (NHBS-IDU1 and NHBS-IDU2). Time trends that might influence the comparisons were assessed by the use of data from reported HIV cases in IDU, surveys of needle exchange users, and two previous IDU studies.

Variations in patterns of sexual risk behavior among Seattle-area MSM based on their HIV status, the HIV status of their partner and partner type.

We evaluated sexual risk behavior in 368 Seattle-area MSM recruited in the 2008 National HIV Behavioral Surveillance survey. We found significant concordance between participants' self-reported HIV status and that of their sexual partners. Persons unaware of partners' HIV status were more likely to report only oral sex.

Evaluating respondent-driven sampling in a major metropolitan area: Comparing injection drug users in the 2005 Seattle area national HIV behavioral surveillance system survey with participants in the RAVEN and Kiwi studies.

Purpose: To empirically evaluate respondent-driven sampling (RDS) recruitment methods, which have been proposed as an advantageous means of surveying hidden populations.

Methods: The National HIV Behavioral Surveillance system used RDS to recruit 370 injection drug users (IDU) in the Seattle area in 2005 (NHBS-IDU1). We compared the NHBS-IDU1 estimates of participants' area of residence, age, race, sex, and drug most frequently injected to corresponding data from two previous surveys, the RAVEN and Kiwi Studies, and to persons newly diagnosed with HIV/AIDS and reported from 2001 through 2005.

Serosorting for hepatitis C status in the sharing of injection equipment among Seattle area injection drug users.

Background: Hepatitis C virus (HCV) is a major health problem among injection drug users (IDU). One potential means of reducing risk of HCV transmission among IDU is serosorting, whereby IDU preferentially share injection equipment with persons of like HCV status.

Methods: We surveyed Seattle area IDU recruited by respondent-driven sampling as part of the National HIV/AIDS Behavioral Surveillance system in 2005.

Trends in hepatitis B virus, hepatitis C virus, and human immunodeficiency virus prevalence, risk behaviors, and preventive measures among Seattle injection drug users aged 18-30 years, 1994-2004.

Injection drug users (IDUs) are at risk for infection with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Information on time trends in prevalence of these viruses among IDUs and in behaviors influencing their transmission can help define the status of these epidemics and of public health efforts to control them. We conducted a secondary data analysis combining cross-sectional data from IDUs aged 18-30 years enrolled in four Seattle-area studies from 1994 to 2004.