Gender differences in injection risk behaviors at the first injection episode

Abstract

Objectives

To examine gender differences in drug injection equipment sharing at injecting initiation.

Methods

Young injecting drug users (IDUs) in New York City February 1999–2003 were surveyed about injection risk behaviors and circumstances at initiation. Analyses were gender-stratified and excluded participants who initiated alone. Multiple logistic regression estimated adjusted odds ratios.

Results

Participants (n = 249) were 66% male and 82% White. Mean initiation age was 19.2; mean years since initiating was 3.0. Women were significantly more likely to cite social network influence as a reason for initiating, to have male and sex partner initiators, and to share injecting equipment than men. Among women, sharing any injection equipment was associated with initiation by a sex partner and having ≥2 people present. Among men, being injected by someone else predicted sharing any injection equipment, while using a legally obtained syringe was protective.

Conclusions

Social persuasion stemming from sexual and/or social relationships with IDUs may increase women's risk of sharing injection equipment at initiation, and consequently, their early parenteral risk of acquiring blood-borne infections. Interventions should focus on likely initiates, especially women in injecting-discordant sex partnerships, and IDUs (potential initiators).

Introduction

Many new injecting drug users (IDUs) are at risk of infection with blood-borne infections such as HIV, the Hepatitis B virus (HBV) and the Hepatitis C virus (HCV) within their first few years of initiating injecting (Friedman et al., 1989, Nicolosi et al., 1992, Garfein et al., 1996, Fennema et al., 1997, Doherty et al., 2000a). Female new IDUs, in particular, may be at increased risk for early infection. Studies in New York City (NYC), for instance, have found higher HIV seroprevalence among female new IDUs than among male new IDUs (Friedman et al., 1993, Des Jarlais et al., 1999), and female new IDUs in NYC have also been found to be significantly more likely to be infected with HCV than male IDUs (Neaigus et al., 2007). The very first injection has increasingly been recognized as a potentially vulnerable time for the transmission of blood-borne infections. While a growing number of studies have examined circumstances around the first injection episode (Hser et al., 1987, Stenbacka, 1990, Crofts et al., 1996, Atwood, 1999, Doherty et al., 2000b, Roy et al., 2002), and the relationship of these circumstances to current risk behavior (Chitwood et al., 2000, Vidal-Trecan et al., 2002, Treloar et al., 2003, Novelli et al., 2005), little is known about gender differences in injection risk behavior at the initiation event, and the circumstances that may be associated with such risk. Interventions targeted at preventing infection among those non-injecting drug users who may be at risk of transitioning to injecting, such as individuals in injecting-discordant relationships, require information that can help elucidate the social and circumstantial predictors of infection risk at injecting initiation, and how these predictors may vary by gender.

Initiates to injecting are at high risk of infection during the first injecting event for a variety of reasons. The first injection event is often unplanned (Crofts et al., 1996, Doherty et al., 2000b, Vidal-Trecan et al., 2002, Treloar et al., 2003), and thus initiates may not have opportunity to obtain either clean syringes or clean drug preparation equipment, such as cookers used to mix and heat the drugs, cottons used to filter out the drug's impurities, or water used to dissolve the drugs or rinse equipment. Inexperienced injectors may also be ill-informed regarding the risks associated with sharing injection paraphernalia due to their lower levels of contact with harm reduction services (Treloar et al., 2003). Moreover, initiates may be subject to the influence of their initiators, many of whom may be more likely to have previously engaged in injection risk behavior (Kral et al., 1999, Day et al., 2005) and thus may be high risk sharing partners.

Gender may be an additional determinant of risk-taking behavior at injecting initiation. Many studies have found that female IDUs were more likely than men to have been initiated by male sexual partners (Powis et al., 1996, Crofts et al., 1996, Diaz et al., 2002, Evans et al., 2003). Several studies of IDUs’ injecting behavior have shown that it is common for women to use syringes and ancillary drug preparation equipment after men have used them to inject themselves (Sotheran et al., 1992, Davies et al., 1996, Bennett et al., 2000). Others have found that sharing drug injecting equipment is frequent among women who have injecting sex partners (Barnard, 1993, Neaigus et al., 1995, MacRae and Aalto, 2000, Evans et al., 2003, Tortu et al., 2003).

In the following, we describe the circumstances of injecting initiation in a sample of young, predominantly White, new IDUs recruited in New York City, and compare by gender the influence of the circumstances of initiating injecting on the prevalence of injection risk behavior at the initiation event. We evaluate the hypotheses that women are more likely to engage in injection risk behavior at the first injection, and that the correlates of injection risk at initiation will vary by gender.