UNSAFE INJECTION PRACTICES IN A COHORT OF INJECTION DRUG USERS IN VANCOUVER

COULD SAFER INJECTING ROOMS HELP?

Abstract

Background

In several European countries safer injecting rooms have reduced the
public disorder and health-related problems of injection drug use. We
explored factors associated with needle-sharing practices that could
potentially be alleviated by the availability of safer injecting rooms
in Canada.

Methods

The Vancouver Injection Drug User Study is a prospective cohort study
of injection drug users (IDUs) that began in 1996. The analyses
reported here were restricted to the 776 participants who reported
actively injecting drugs in the 6 months before the most recent
follow-up visit, during the period January 1999 to October 2000.
Needle sharing was defined as either borrowing or lending a used
needle in the 6-month period.

Results

Overall, 214 (27.6%) of the participants reported sharing needles
during the 6 months before follow-up; 106 (13.7%) injected drugs in
public, and 581 (74.9%) reported injecting alone at least once.
Variables independently associated with needle sharing in a
multivariate analysis included difficulty getting sterile needles
(adjusted odds ratio [OR] 2.7, 95% confidence interval [CI] 1.8-4.1),
requiring help to inject drugs (adjusted OR 2.0, 95% CI 1.4-2.8),
needle reuse (adjusted OR 1.8, 95% CI 1.3-2.6), frequent cocaine
injection (adjusted OR 1.6, 95% CI 1.1-2.3) and frequent heroin
injection (adjusted OR 1.5, 95% CI 1.04-2.1). Conversely, HIV-positive
participants were less likely to share needles (adjusted OR 0.5, 95%
CI 0.4-0.8), although 20.2% of the HIV-positive IDUs still reported
sharing needles.

Interpretation

Despite the availability of a large needle-exchange program and
targeted law enforcement efforts in Vancouver, needle sharing remains
an alarmingly common practice in our cohort. We identified a number of
risk behaviours -- difficulty getting sterile needles, needle sharing
and reuse, injection of drugs in public and injecting alone (one of
the main contributing causes of overdosing) -- that may be alleviated
by the establishment of supervised safer injecting rooms.

Introduction

The incidence of fatal overdoses and the emergence of the HIV epidemic
among injection drug users (IDUs) have led to wider recognition that
illicit drug use is a public health problem. Public health initiatives
aimed at preventing overdoses and disease transmission among IDUs are
referred to as harm reduction. [1] In addition to prevention, harm
reduction aims to protect drug users by enabling them to inject safely
until they can be helped off drugs. [2] A cornerstone of harm
reduction is making sterile needles available through needle-exchange
programs and other means. [3] Although needle exchange is accepted as
a public health intervention in many cities in Canada, the apparent
tolerance of drug use associated with it has made needle exchange
controversial in some smaller Canadian settings and in many countries
around the world. [4] Nevertheless, overwhelming evidence indicates
that needle-exchange programs can substantially reduce HIV risk
behaviour and the transmission of bloodborne infections, including
HIV. [5,6,7,8] However, such programs have not been sufficient to
prevent HIV epidemics in all settings. This is true of Vancouver's
Downtown Eastside, where an HIV epidemic, characterized by a peak
annual incidence rate of 18%, was documented in 1997 despite the
presence of a needle-exchange program. [9] The inability of the
program to prevent this epidemic was later attributed to specific
local factors, including a high prevalence of cocaine injection. [10]

As in many other settings, a primary response to the HIV epidemic was
to increase targeted law enforcement efforts in the Downtown Eastside
so that greater numbers of police officers could patrol the
neighbourhood's alleys and other areas where drug use is concentrated.
[11] Currently in Canada the vast majority of resources aimed at
preventing the harms of drugs are now allocated to policing. In
British Columbia, 82% of the total direct costs associated with
illicit drug use are accounted for by law enforcement. [12] Despite
the resources provided to law enforcement, the incidence of hepatitis
C and HIV infection in Vancouver's Downtown Eastside indicate that a
substantial number of IDUs continue to share needles. [13]
Furthermore, the region continues to experience an epidemic of
overdoses, 312 occurring on average each year since 1996. [14]

A harm reduction intervention that has been highly effective elsewhere
is safer injecting rooms, which are legally sanctioned and supervised
facilities where IDUs can inject pre-obtained illicit drugs. Within
these facilities, IDUs are provided access to health care and other
services as well as sterile injecting equipment. [15,16] Although
safer injecting rooms have not been established in North America, over
45 of them now operate in about a dozen European cites, and a facility
has recently opened in Australia. [15] The reported benefits of these
facilities include improved health and social functioning of clients,
reductions in public disorder (e.g., drug injection, intoxication and
discarding of needles in public), reductions in overdoses and
reductions in risk behaviours for disease transmission.
[15,16,17,18,19]

Several cities in Canada, including Vancouver, [20] are considering
scientific evaluations of safer injecting rooms. These proposals have
met resistance from community groups expressing fear that the drug
epidemic in Canada is such that the European experience is unlikely to
be replicated here. [21,22] Therefore, we conducted analyses to
examine factors associated with needle sharing among Vancouver IDUs
and to evaluate whether any of these factors could potentially be
alleviated by the establishment of safer injecting rooms.

Methods

Beginning in May 1996 people who had injected illicit drugs in the
previous month were recruited into the Vancouver Injection Drug User
Study. In brief, over 1400 subjects were recruited through
self-referral and street outreach efforts. Eligible subjects were
those who had injected illicit drugs at least once in the previous
month, resided in the Greater Vancouver area and provided written
informed consent. At baseline and semi-annually, subjects provided
blood samples and completed an interviewer-administered questionnaire.
The questionnaire was designed to elicit demographic data and
information about drug use, HIV risk behaviours and drug treatment.

For our analyses, we included baseline data and data from the most
recent follow-up questionnaire available (administered during January
1999 to October 2000). Demographic characteristics such as age, sex
and ethnic background were derived from the baseline questionnaire. To
evaluate current drug injection practices, information such as drug
use and health-related characteristics such as HIV status were
obtained from the most recent follow-up questionnaire.

We chose needle sharing as the dependent variable because this
behaviour has been shown to have the highest risk of HIV transmission
among IDUs. Needle sharing was defined as either the lending or
borrowing of a used needle in the 6 months before the follow-up visit.
We did not restrict our analyses to needle sharing with either casual
or intimate partners, because we have recently shown that both risk
behaviours are associated with HIV seroconversion among IDUs in
Vancouver. [23] People who had not injected drugs in the 6 months
before the most recent follow-up visit were excluded from our
analyses, because we sought to evaluate predictors of needle sharing
among people who were actively injecting drugs. We also examined, and
report on briefly in this article, the proportion of IDUs who reported
sharing needles as defined above in the cohort during the prior 5
follow-up visits.

Univariate and multivariate analyses were performed to determine
factors associated with current needle sharing practices.
Sociodemographic and behavioural characteristics considered in the
analyses included age, sex, ethnic background, education level, HIV
status, and self-report at baseline of ever having had a diagnosis of
mental illness. We also considered information on the receipt of
methadone treatment, being refused drug treatment, being refused
sterile needles at pharmacies and requiring help injecting.

Characteristics of drug use considered in our analyses included
difficulty getting sterile needles, frequency of cocaine and heroin
injection, average use of needles (once v. more than once), nonfatal
overdoses, injection in public, safety of needle disposal and
frequency of injecting alone. As we have done previously, [9,10]
frequent cocaine or heroin use was defined as injection of the drug
once or more daily. Safe needle disposal was defined as the placement
of needles in a "safe place" or a sharps container or the return of
needles to the needle-exchange program. To evaluate the effect of
police activities on drug use, we considered the number of subjects
who reported that police activities affected their source of drugs.

Statistical analyses were used to compare IDUs who shared needles and
those who did not share needles in the 6 months before the most recent
follow-up visit. Categorical explanatory variables were analyzed using
Pearson's c2 test, and continuous variables were analyzed using the
Wilcoxon rank-sum test. All variables that were statistically
significant at the 0.05 cutoff point were considered in a logistic
regression analysis. All reported p values are two-sided.

Results

Since the study's inception, 124 participants have died (28 of
HIV/AIDS, 41 of an overdose and 55 of other causes). A total of 962
participants responded to at least 1 questionnaire during the period
January 1999 to October 2000 and were therefore eligible for our
study. Compared with the 351 participants who did not come in for the
most recent follow-up, those included in our study were more likely to
be female (p = 0.001), Aboriginal (p = 0.001), HIV-positive at last
follow-up (p = 0.001), older (p ( 0.001) and have a high school
education (p = 0.006). No significant differences were found between
the groups with regard to difficulty acquiring clean needles (p
0.30), frequency of cocaine injection (p = 0.72) or heroin injection
(p = 0.93), or need for help injecting (p = 0.84). Of the 962
participants eligible for our study, 776 (80.7%) reported injecting
drugs in the 6 months before the most recent follow-up visit and were
therefore included in our analyses; 562 (72.4%) reported not sharing
needles and 214 (27.6%) reported sharing needles in that 6-month
period. The proportions of active IDUs who reported needle sharing at
the 4 follow-up visits before the study period were 31.2%, 22.7%,
23.5% and 25.5% respectively. Of the 247 HIV-positive IDUs, 20.2%
reported sharing needles in the 6 months before the most recent
follow-up visit. Of the 776 IDUs in our study, 106 (13.7%) injected
drugs in public, and 581 (74.9%) injected alone at least once.

The results of the univariate analysis of sociodemographic and
health-related characteristics are shown in Table 1. Being refused
sterile needles at pharmacies (odds ratio [OR] 2.0) and requiring help
to inject drugs (OR 1.9) were positively associated with sharing
needles. Although not achieving statistical significance, having a
diagnosis of mental illness was associated with sharing needles (OR
1.4, p = 0.07). Alternatively, being older (OR 0.97 per year of age
[95% CI 0.95-0.99]; data not shown), and being HIV positive (OR 0.6)
were inversely associated with needle sharing. We found no evidence
that ethnic background, education level, sex, receipt of methadone
treatment or being refused drug addiction treatment were associated
with needle sharing.

The results of the univariate analysis of drug use and behavioural
characteristics are shown in Table 2. Factors positively associated
with needle sharing were difficulty getting sterile needles (OR 3.1),
frequent cocaine injection (OR 1.6), frequent heroin injection (OR
1.8), use of needles more than once on average (OR 2.0), nonfatal
overdose (OR 1.7) and reporting that police activities had affected
the source of drugs (OR 1.9). We found no evidence that injection in
public, unsafe needle disposal or injecting alone were associated with
needle sharing.

The variables that were found to be independently associated with
needle sharing in the stepwise logistic regression analyses are listed
in Table 3. Difficulty getting sterile needles (adjusted OR 2.7),
requiring help to inject drugs (adjusted OR 2.0), frequent cocaine
injection (adjusted OR 1.6), frequent heroin injection (adjusted OR
1.5) and use of needles more than once on average (adjusted OR 1.8)
were all positively associated with needle sharing. HIV-positive
status was inversely associated with needle sharing (adjusted OR 0.5).
Interpretation Despite targeted police efforts and a large
needle-exchange program in Vancouver's Downtown Eastside, 27.6% of the
IDUs included in our study reported sharing needles, and 9.7% had had
a nonfatal overdose in the 6 months before the most recent follow-up
visit. Having difficulty getting sterile needles, needing help
injecting, reusing needles, and frequent cocaine and heroin injection
were all associated with needle sharing.

Several of our findings suggest that barriers to sterile needle use
persist despite the presence of a large needle-exchange program. [9]
Although expanding the program would likely help to reduce needle
sharing further, several risk factors remained independently
associated with needle sharing after adjustment for difficulty getting
needles. Furthermore, 19.1% of the participants included in our study
shared needles even though they did not report having difficulty
getting sterile needles. All of these factors suggest that expansion
of the needle-exchange program alone will not be sufficient to
eliminate this risk.

Several conditions, such as lack of experience or physical disability,
may place IDUs in need of help with injections. The high prevalence of
assisted injection has been documented in other settings, [24]
although the strong association with HIV risk behaviour has not been
previously established to our knowledge. Again, adequate availability
of sterile needles will probably not be sufficient to mitigate this
risk behaviour.

We also found that subjects who were HIV-positive were half as likely
as HIV-negative IDUs to share needles. This suggests a benefit of HIV
testing and counselling in this community. [25] However, despite
substantial outreach services offering testing and counselling to IDUs
in Vancouver, only 15.0% of the participants in our study had ever had
an HIV test before recruitment into the study (unpublished data).

Another major problem associated with injection drug use is death from
overdose. In Canada, British Columbia has the highest number of such
deaths per capita, with about 4.7 per 100 000 population annually, and
in several recent years illicit drugs have been the leading cause of
death among adults 30 to 49 years of age. [12,14] Although
needle-exchange programs have been associated with reductions in
overdoses, 26 overdoses continue to occur all too frequently among
IDUs.

Several of the variables we examined highlight the public disorder
problems associated with injection drug use. For instance, in the 6
months before the most recent follow-up visit 13.7% of the
participants in our study reported injecting drugs in public and 45.6%
reported that they did not always practise safe needle disposal.

We found a positive association between police activities and needle
sharing. Although further study of this association is required, the
potentially negative consequences of policing efforts on HIV risk
behaviour, such as creating fear of possessing needles, have been
reported elsewhere. [27,28]

Our study has several limitations. Compared with the IDUs included in
our study, those who did not come in for the most recent follow-up had
a number of characteristics (e.g., younger and more likely to be HIV
negative) that may make them more likely to be involved in needle
sharing. Furthermore, it has been shown previously that IDUs may
substantially underreport HIV risk behaviour and that HIV testing and
counselling that accompany cohort studies such as ours may reduce risk
behaviour over time. [29,30] Therefore, we may have underestimated the
extent of needle sharing among IDUs.

In summary, our data demonstrate a continued health crisis among IDUs.
Furthermore, the proportion of IDUs who reported needle sharing did
not decrease over the past 5 follow-up visits, despite the presence of
a large needle-exchange program and targeted law enforcement efforts.

Meanwhile, in several European cities, the risk factors we identified
have proven amenable to improvement through the establishment of safer
injecting rooms as part of comprehensive harm reduction strategies.
Increases in HIV testing and counselling, health and social
functioning, and drug addiction treatment have occurred among clients
of safer injecting rooms in these cities. [15,16,31] Conversely, the
incidence of HIV risk behaviour including needle sharing, hospital
admissions, improper needle disposal, drug injection in public places
and death from overdose have all decreased. [15,16,31,32] In fact,
there has not been a fatal overdose in a safer injecting room since
their establishment in the mid-1980's. [17] In the present study we
did not evaluate safer injecting rooms per se. We have merely
identified risk factors among IDUs that have proven amenable to
improvement through the availability of such facilities in other
settings. [15,16,31,32] Given the high prevalence of HIV risk
behaviours, overdoses and other health-related concerns that persist
in Vancouver, it is crucial to evaluate whether the European
experience with safer injecting rooms can be replicated in Canada.

Competing Interests None declared.

Contributors Mr. Wood and Dr. Schechter were the principal authors and
were involved in all aspects of the study. Drs. Tyndall, Spittal,
Hogg, Montaner and O'Shaughnessy were involved in the original concept
and design of the study and in revising the manuscript. Mr. Kerr
prepared much of the background material and literature review on
safer injecting rooms and was involved in revising the manuscript. Ms.
Li was involved in data collection, statistical analyses, and drafting
and revising the manuscript.

Acknowledgments We thank Bonnie Devlin, Caitlin Johnston, Robin
Brooks, Suzy Coulter, Steve Kain, Guillermo Fernandez, John Charette,
Will Small and Nancy Laliberte for their research and administrative
assistance. We also thank all of the participants in the Vancouver
Injection Drug User Study.

The study was supported by the US National Institutes of Health (grant
no. RO1 DA11591). Mr. Wood is supported by the Canadian Institutes for
Health Research and the British Columbia Health Research Foundation.
Dr. Schechter holds a tier I Canada Research Chair in HIV/AIDS and
Urban Population Health.

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