Incidence and risk factors for non-fatal overdose among a cohort of recently incarcerated illicit drug users

Abstract

Background Release from prison is associated with a markedly increased risk of both fatal and non-fatal drug overdose, yet the risk factors for overdose in recently released prisoners are poorly understood. The aim of this study was to identify risk and protective factors for non-fatal overdose (NFOD) among a cohort of illicit drug users in Vancouver, Canada, according to recent incarceration. Methods Prospective cohort of 2515 community-recruited illicit drug users in Vancouver, Canada, followed from 1996 to 2010. We examined factors associated with NFOD in the past six months separately among those who did and did not also report incarceration in the last six months. Results One third of participants (n=829, 33.0%) reported at least one recent NFOD. Among those recently incarcerated, risk factors independently and positively associated with NFOD included daily use of heroin, benzodiazepines, cocaine or methamphetamine, binge drug use, public injecting and previous NFOD. Older age, methadone maintenance treatment and HIV seropositivity were protective against NFOD. A similar set of risk factors was identified among those who had not been incarcerated recently. Conclusions Among this cohort, and irrespective of recent incarceration, NFOD was associated with a range of modifiable risk factors including more frequent and riskier patterns of drug use. Not all ex-prisoners are at equal risk of overdose and there remains an urgent need to develop and implement evidence-based preventive interventions, targeting those with modifiable risk factors in this high risk group.

Factors associated with history of non-fatal overdose among young nonmedical users of prescription drugs

“…Previous studies have consistently found that misuse of prescription opioids and tranquilizers is a risk factor of fatal and non-fatal OD (Paulozzi et al, 2012; Kinner et al, 2012; Hakansson et al, 2008; McGregor et al, 1998; Charlson et al, 2009; Gossop et al, 2002). However, the present study’s sampling strategy, which included various high-risk groups of young adults (e.g., IDUs and homeless, non-IDU), is an important development in this line of research because much of the prior research has exclusively focused on IDUs or older, drug-dependent heroin users.…”

“…Nonetheless, one study estimated the lifetime prevalence of non-fatal OD among young IDUs to be approximately 30% and found that risk of OD was associated with being White, homeless, using tranquilizers, and having a prolonged history of injection drug use (Sherman et al, 2007). Studies on older IDUs have described additional risk factors associated with non-fatal OD that include male gender (Bohnert et al, 2010), substance use disorders (Darke et al, 1996; Galea et al, 2006; Kaye and Darke, 2004; Maloney et al, 2009), history of drug treatment (Neale and Robertson, 2005; Darke et al, 2004), history of incarceration (Kinner et al, 2012; Britton et al, 2010; Havens et al, 2011; Wines et al, 2007), psychological distress (Tobin and Latkin, 2003; Havens et al, 2011; Bohnert et al, 2012; Latkin et al, 2004; Maloney et al, 2009), parental drug problems (Hakansson et al, 2008), injection of prescription opioids (Havens et al, 2011), and concurrent use of heroin and prescription drugs (Kerr et al, 2007). …”

“…For instance, injection of prescription opioids has been associated with non-fatal OD in some studies (Havens et al, 2011), while non-injection opioid use is associated in others (Kerr et al, 2007). Moreover, several studies have reported tranquilizer use as a significant predictor of OD (Kinner et al, 2012; Hakansson et al, 2008; McGregor et al, 1998; Charlson et al, 2009; Gossop et al, 2002), but none have examined whether this association is related to mode of drug administration.…”

Public drug injecting in London, Ontario: a cross-sectional survey

“…[7][8][9] Public injecting tends to be concentrated among the most vulnerable people who inject drugs, being independently associated with homelessness, recent incarceration, high-intensity drug use (e.g., injecting daily or more) and injecting-related risks (e.g., nonfatal overdose, needle-sharing, not cooking and filtering drugs) in several large Canadian cities. [1][2][3][4]6,10,11 At a community level, public injecting is perceived as a threat to public order and contributes to improper disposal of injection-related litter. 12 Although these public health and order challenges posed by public injecting in major urban centres are well-documented, little is known about challenges that public injecting may pose for smaller municipalities.…”

Nonfatal overdose from alcohol and/or drugs among a sample of recreational drug users

“…In addition, a temporal relationship was not established between nonfatal overdose and the independent variables, therefore causal relationships cannot be established from this study (Kerr et al, 2007). Moreover, there is evidence from other drug using populations that recent release from prison and being in treatment for drug use increases risk of both fatal and nonfatal overdose (Fischer et al, 2004;Kinner et al, 2012). Future studies should address this in order to test whether these relationships are present among recreational drug users.…”