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Journal of Addictive Diseases
ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/wjad20
Factors associated with injecting-related risk
behaviors among people who inject drugs: a
systematic review and meta-analysis study
Omid Rezaei , Hesam Ghiasvand , Peter Higgs , Alireza Noroozi , Mehdi
Noroozi , Fatemeh Rezaei , Bahram Armoon & Azadeh Bayani
To cite this article: Omid Rezaei , Hesam Ghiasvand , Peter Higgs , Alireza Noroozi , Mehdi
Noroozi , Fatemeh Rezaei , Bahram Armoon & Azadeh Bayani (2020): Factors associated with
injecting-related risk behaviors among people who inject drugs: a systematic review and meta-
analysis study, Journal of Addictive Diseases, DOI: 10.1080/10550887.2020.1781346
To link to this article: https://doi.org/10.1080/10550887.2020.1781346
Published online: 07 Jul 2020.
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Factors associated with injecting-related risk behaviors among people
who inject drugs: a systematic review and meta-analysis study
Omid Rezaei, MD
a
, Hesam Ghiasvand, PhD
b,c
, Peter Higgs, PhD
d
, Alireza Noroozi, MD
e,f
, Mehdi Noroozi,
PhD
g
, Fatemeh Rezaei, MSc
h
, Bahram Armoon, PhD
i
, and Azadeh Bayani, MSc
j
a
Fellowship of Psychosomatic, Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran;
b
Health Management and Economics Research Center, Iran University of Medical Sciences, Tehran, Iran;
c
Health Economics Group,
Medical School, Saint Luke’s Campus, University of Exeter, Exeter, UK;
d
Department of Public Health, La Trobe University, Melbourne,
Australia;
e
Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran;
f
Department of
Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran,
Iran;
g
Social Determinants of Health Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran;
h
Department of Epidemiology and Biostatics, Jahrom University of Medical Sciences, Jahrom, Iran;
i
Social Determinants of Health
Research Center, Saveh University of Medical Sciences, Saveh, Iran;
j
Student Research Committee, School of Allied Medical Sciences,
Shahid Beheshti University of Medical Sciences, Tehran, Iran
ABSTRACT
We conducted this systematic review and meta-analysis study to better understand the fac-
tors (being drug use, drug type (methamphetamine vs others), sex partner, frequency of
injection, homelessness and being HIV positive) associated with injecting-related risk behav-
iors (lending and/or borrowing already used syringes) among people who inject drugs
(PWID). We searched the English language citations in PubMed, Science Direct, Web of
Science, and Cochrane electronic databases for previous studies on risk behaviors among
PWID. Two independent researchers reviewed all search results, screened for eligibility and
extracted data independently. A meta-analysis was conducted with pooled odds ratio and
the 95% confidence intervals for factors associated with injecting risk behaviors among
PWID. After detailed assessment of the citations, we included 14 studies in our meta-ana-
lysis. Binge drug use (OR, 1.39; 95% CI, 1.06–1.71) and drug type (methamphetamine vs.
others) (OR, 1.50; 95% CI, 1.22–1.77) were positively associated with the borrowing of
already used syringes among PWID. We also found that drug type (OR, 1.39; 95% CI,
1.16–1.64) and homelessness (OR, 1.89; 95% CI, 1.27–2.51) had a positive association with
the lending of already used syringes among PWID. Additionally, being HIV positive was
negatively associated with the lending of used syringes among PWID (OR, 0.58; 95% CI,
0.37–0.63). This systematic review and meta-analysis supports harm-reduction initiatives
especially the establishment and maintenance of sterile needle syringe programs.
KEYWORDS
Risk behaviors; people who
inject drugs; borrowing
syringes; lending syringes
Background
Recent global estimates for the number of people
who inject drugs (PWID) were 15.6 million with
one in six living with HIV and more than half
living with hepatitis C virus (HCV).
1
The sharing
of previously used drug injection paraphernalia
(especially needles and syringes) is the prime rea-
son for transmission of these blood borne viruses
(BBVs) in both developed and developing coun-
tries.
2
Condomless sex among and between
PWID is also noted as a high risk behavior for
BBV transmission, especially HIV and hepatitis
B, though this varies substantially between coun-
tries.
1
Earlier studies regarding HIV-related risk
taking among PWID have generally divided sex-
ual and injecting-related risk behaviors and
shown that those who share syringes, are the
most at risk group for HIV transmission.
3,4
The
borrowing and lending of already used needles
and syringes are the main reason for HCV infec-
tion with previous studies demonstrating the
risks of transmission among PWID.
5,6
Concerns
about individual and community health have
CONTACT Bahram Armoon, PhD bahramarmun@gmail.com Assistant Professor of Health Education and Promotion, Social Determinants of Health
Research Center, Saveh University of Medical Sciences, Saveh, Iran.
Supplemental data for this article can be accessed at https://doi.org/10.1080/10550887.2020.1781346.
ß2020 Taylor & Francis Group, LLC
JOURNAL OF ADDICTIVE DISEASES
https://doi.org/10.1080/10550887.2020.1781346
been raised because of the strong relationship between
injection drug use and spread of BBV infection.
7
Previous research documenting risk taking
behaviors among PWID has mostly been framed
from two perspectives: unsafe (condomless) sex
and the sharing of used injection equipment,
with these two variables being evaluated individu-
ally. The borrowing of used injection equipment
is a high risk for transmission among both HCV
positive and negative Inject drug users (IDUs).
8
Evidence suggests that people living with HCV
who continue to share their injecting equipment
risk reinfection with HCV or superinfection with
different genotypes of HCV.
9,10
Evidence from
San Francisco also suggests that HCV negative
PWID refuse to share their injection equipment
to prevent infection.
11
The sharing of injecting
equipment, as well as condomless sex, increases
the risk of infection with other blood borne
pathogens such as human immunodeficiency
virus (HIV) and hepatitis B virus among
PWID.
12–15
While previous research has shown
that PWID are able to modify their behavior to
prevent HIV,
14,16–19
few studies identifying risk
behaviors have only considered injecting risk
behaviors such as the lending and borrowing
of syringes.
Increasing awareness of the factors associated
with borrowing and lending of already used nee-
dles, syringes or other injecting paraphernalia are
important for policy-making and public health
planning purposes.
20
While previous systematic
reviews on the effectiveness of sterile needle and
syringe programs
21
have shown them to be one
of the best ways to reduce BBV transmission,
21–25
there has yet to be a systematic review and meta-
analysis assessing the factors associated with bor-
rowing and lending of used syringes among
PWID. This study differs from prior studies in
three important respects. First, we have included
data from studies published between 1987 and
2018, thereby updating previous reviews
24,26
by
over 15 years. In Ksobiech’s study
24
the focus was
on associations between needle syringe program
27
attendance and reductions in needle sharing-
related risk behaviors. They found that needle
and syringe programmes (NSPs) reduced risk
behaviors of PWID including the borrowing and
lending of already used injecting equipment.
Data from these studies include a large num-
ber of needle sharing variables, so they cannot
detect the importance of the borrowing and lend-
ing already used equipment. We designed this
systematic review and meta-analysis study to bet-
ter understand the factors (being drug use, drug
type (methamphetamine versus others), sex part-
ner, frequency of injection, homelessness and
being HIV positive) associated with injecting-
related risk behaviors (lending and/or borrowing
of needles and syringes) among PWID.
Methods
This study used the risk factors identified from
Protocols of Systematic Reviews and Meta-
Analyses (PRISMA).
28–31
Search strategy and study selection
We searched the PubMed, Science Direct, Web of
Science, and Cochrane electronic databases to find
previous studies on risk taking behaviors among
PWID for the period June 1980 –February 2018.
The study search strategy is presented in Table 1.
Furthermore, other available reviews regarding
high-risk behaviors among PWID were assessed.
All papers with an English language abstract were
included in the search. Post assessment with a
duplicate filter two independent researchers (B.A.
and H.Gh.) analyzed the search results based on
title, abstract and relevance to the subject.
Any study design (Cross-sectional, cohort, and
case-control studies) were included in the review.
Qualitative studies, secondary studies, systematic
reviews and meta-analysis studies and papers in
languages other than English were excluded.
Inclusion criteria based on PICO:
Population: Studies that were conducted
among PWID.
Intervention: Outcomes of interest included drug
use, drug type (methamphetamine versus others),
sex partner, frequency of injection, homelessness
and being HIV positive in each of the studies
and these were considered as the intervention.
Comparison Group: Participants not reporting
the borrowing and/or lending of already used
needles and syringes.
2 O. REZAEI ET AL.
Outcomes: Lending and/or borrowing syringe
were considered as the risk behaviors of interest.
Data extraction and study quality assessment
The items extracted from the chosen studies
included the first author’s name and publication
year, sample characteristics, location, and design
of the study, and also data on the exposure and
outcomes variables. We considered significant
factors, effect measure, performed adjustments,
and the analytical methods used. If we had any
ambiguities, we contacted the authors to resolve
them. We used previously defined worksheets for
recording the required data separately. First, the
authors reviewed and deleted any duplicate title
and abstract. Agreement between reviewers
according to the criteria one through three was
89%. In the second phase titles/abstracts that
qualified based on the defined criteria were
chosen for full-text review (96% agreement). For
the quality evaluation, we performed the
unweighted kappa approach to assess the
agreement between the two authors (B.A. and
A.B.). We defined the levels of agreement (poor,
slight, fair, moderate, substantial) with the values
of 0, 01–0.02, 0.021–0.04, 0.041–0.06, 0.061–0.08,
and 0.081–1.00, respectively.
32
Microsoft Excel software was used to extract
the data and two researchers (H.Gh. and B.A.)
reviewed and assessed papers independently
using a standardized data collection form. Any
conflict of ideas among reviewers was resolved
through discussion with other authors (H.Gh.
and M.N.). Researchers extracted the required
data including the year of publication, demo-
graphic data of samples (age, sex) and other
characteristics like binge drug use (defined as
going on drug ‘‘runs’’ or ‘‘binges’’ indicating
drugswereusedmorethanusualinonesitting),
the frequency of drug injecting, types of drug
used (methamphetamine use), history of HIV
testing, and HIV status independently. The qual-
ity of all reviewed papers was evaluated by the
Newcastle-Ottawa Scale
33
suggested by the
Cochrane Collaboration.
34
Table 1. Search strategy by indexing website.
PubMed (Syringe Program[Title])) OR borrowing syringes[Title/Abstract]) OR lent syringes[Title/
Abstract]) OR Receptive sharing[Title/Abstract]) OR Distributive sharing[Title/Abstract])
AND Needle Sharing[MeSH Terms] OR Syringes[MeSH Terms]
ScienceDirect TITLE-ABSTR-KEY(Needle Sharing) and TITLE-ABSTR-KEY(borrowing syringes).
TITLE-ABSTR-KEY(Needle Sharing) and TITLE-ABSTR-KEY(Receptive sharing).
TITLE-ABSTR-KEY(Needle-Exchange Programs) and TITLE-ABSTR-KEY(borrowing syringes).
TITLE-ABSTR-KEY(Needle-Exchange Programs) and TITLE-ABSTR-KEY(Receptive sharing).
TITLE-ABSTR-KEY(Needle Sharing) and TITLE-ABSTR-KEY(lent syringes).
TITLE-ABSTR-KEY(Needle Sharing) and TITLE-ABSTR-KEY(Distributive sharing).
TITLE-ABSTR-KEY(Needle-Exchange Programs) and TITLE-ABSTR-KEY(lent syringes).
TITLE-ABSTR-KEY(Needle-Exchange Programs) and TITLE-ABSTR-KEY(Distributive sharing).
Web of Knowledge TS¼(Needle-Exchange ProgramsAND borrowing syringes) OR TS¼(Needle-Exchange
ProgramsAND lent syringes) Timespan: All years.
TS¼(Needle-Exchange ProgramsAND Receptive sharing) OR TS¼(Needle-Exchange
ProgramsAND Distributive sharing) Timespan: All years.
TS¼(Syringe ProgramAND borrowing syringes) OR TS¼(Syringe ProgramAND
lent syringes)
TS¼( Needle Sharing AND borrowing syringes) OR
TS¼( Needle Sharing AND lent syringes)
TS¼(Syringe ProgramAND Receptive sharing) OR TS¼(Syringe ProgramAND
lent syringes)
TS¼( Needle Sharing AND Receptive sharing) OR
TS¼( Needle Sharing AND Distributive sharing)
TI¼(EffectivenessAND Needle Sharing) OR TI¼(Syringe ProgramAND lent syringes)
TI¼(impactAND Needle Sharing) OR TI¼(Syringe ProgramAND lent syringes)
TI¼(EffectivenessAND Needle Sharing) OR TI¼(Syringe ProgramAND
borrowing syringes)
TI¼(impactAND Needle Sharing) OR TI¼(Syringe ProgramAND lent syringes)
TI¼(EffectivenessAND Needle Sharing) OR TI¼(Syringe ProgramAND
Receptive sharing)
TI¼(impactAND Needle Sharing) OR TI¼(Syringe ProgramAND Distributive sharing)
Cochrane MeSH descriptor: [Needle-Exchange Programs] explode all trees OR MeSH descriptor:
[Syringes] explode all trees AND borrowing syringes:ti,ab,kw OR Receptive sharing:ti,ab,kw
(Word variations have been searched) AND lent syringes:ti,ab,kw OR Distributive
sharing:ti,ab,kw (Word variations have been searched)
JOURNAL OF ADDICTIVE DISEASES 3
Data synthesis and statistical analysis
A meta-analysis was conducted with procreate
pooled odds ratios
35
and the confidence intervals
of 95% on associated factors of injecting risk
behaviors among PWID. Odds ratios (OR) of
research was assessed in 2 2 tables. An OR 1
was considered as not having a positive relation-
ship between being drug use, drug type (metham-
phetamine versus others), homelessness and
being HIV positive) with injecting-related risk
behaviors (lending and/or borrowing syringes).
An OR >1 (as the statistical threshold for evalu-
ating the relationship between outcome variables
and expositive variables) indicates a protective
association between variables and vice versa.
To understand the lack of correlation between
variables, we used Q test with a P value <0.05 and
I
2
statistics with a cutoff of 50%, while 95%
uncertainty intervals were also assessed for I
2
.We
considered any negative values to I
2
as equal to
zero. Considering the varied sampling methods of
the studies, the random effect model was applied
with the aim of evaluating pooled estimation.
Factors associated with injecting risk behaviors
among PWID were explored through an OR and
95% CI, and results were shown in forest plots.
Metan and meta bias commands in STATA ver-
sion 13.0, were applied for data analysis (STATA
Corporation, College Station, TX). In order to
understand any publication bias, we used Begg’s
and Egger’s publication bias method.
36,37
We
considered a P value 0.05 as statistically
significant.
Results
Study selection
A flow diagram depicting the study selection pro-
cess is presented in Figure 1.Intotal,2,704papers
were identified from the four databases and from
additional searches of the reference lists of these
papers. Of these, 2,080 articles were selected for
abstract review. After a detailed assessment of the
citations, we included 14 studies.
38–50
Study characteristics
Table 2 presents the characteristics of the studies.
Synthesis of results/Meta-analysis
There are several risk factors influencing the bor-
rowing and/or the lending of needles and syringes
among PWID. These are shown in Figures2,3,4,
5and 6by forest plots.
Impact of age on borrowing of needles and
syringes among PWID
Figure S1 (supplementary material) is the forest
plot of the effect that age has on the borrowing
of needles and syringes among PWID.
Seven studies
38–43,50
examined the relationship
between age and borrowing and lending of nee-
dles and syringes among PWID. Five studies
were conducted in high-income countries,
38–43
and one in an upper middle-income country
(Thailand).
50
The dates of studies ranged from
1987 to 2017, and the sample sizes were between
145 and 901. Five studies were assessed as having
high quality of evidence and two studies were
categorized as having satisfactory quality of evi-
dence. Six studies used a cohort approach for
their analysis
38,39,41,43,50
and one study used a
cross–sectional design.
42
As illustrated in Figure
S1 (supplementary material) age is negatively
associated with the reporting of lending and/or
borrowing of used needles and syringes and the
heterogeneity is 86.2% and the pooled effect size
implies no significant association. (OR, 0.98; 95%
CI, 0.93–1.03).
Impact of binge drug use on borrowing of needles
and syringes among PWID
Figure 2 shows the effect of “binge drug use”on
the borrowing of syringes among PWID. The
heterogeneity is 0%, and the pooled effect size is
1.39 which implies an association between binge
drug use on borrowing of syringe among PWID.
Three studies
38,44,50
examined the relationship
between binge drug use and borrowing of needles
and syringes among PWID. Two studies were
conducted in high-income countries,
38,44
and one
in an upper middle-income country (Thailand).
50
The dates of studies ranged from 1997 to 2017,
and the sample sizes were between 154 and 505.
Two studies were assessed as having high qual-
ity evidence and one study was categorized as
4 O. REZAEI ET AL.
having a satisfactory quality of evidence. One
study used a cohort approach for their analysis,
38
one study used a cross–sectional design
51
and
another used a case-control design.
44
PWID who reported binge drug use were 1.39
timesmorelikelytoalsoreporttheborrowingofnee-
dles and syringes (OR ¼1.39, 95%CI ¼1.06, 1.71).
Impact of type of drug used (methamphetamine
versus others) on borrowing of needles and
syringes among PWID
Figure 3 presents the association between the
type of drug used (methamphetamine versus
others) and the borrowing of used needles and
syringes among PWID.
Six studies
41,43–45,50
examined the relationship
between methamphetamine use and borrowing of
needles and syringes among PWID. Five studies
were conducted in high-income coun-
tries,
41,43,44,50,52
and one in an upper middle-
income country (Thailand).
50
The dates of studies
ranged from 1992 to 2012, and the sample sizes
were between 125 and 1228. Four studies were
assessed as having high quality evidence and two
studies were categorized as having a satisfactory
quality of evidence. Four studies used a cohort
approach for their analysis,
39,41,43,50
one study
used a cross–sectional design
51
and there was one
case-control designed study.
44
The use of methamphetamine has a positive
impact on the borrowing of already used syringes
among PWID. The pooled effect size is 1.50 with
a confidence interval of between 1.22 and 1.77.
The overall heterogeneity is 46.9%. PWID who
report methamphetamine use were 1.50 times
Figure 1. PRISMA flow diagram.
JOURNAL OF ADDICTIVE DISEASES 5
more likely to report the borrowing of used nee-
dles and syringes (OR, 1.50; 95% CI, 1.22–1.77).
Impact of having a sex partner who also injects
on borrowing of needles and syringes
among PWID
Five studies
40,41,44,52,53
examined the relationship
between having a sex partner who also injects
and borrowing of needles and syringes among
PWID. Five studies were conducted in high-
income countries,
38–43
and one in an upper mid-
dle-income country (Thailand).
50
The studies
were published between 1987 and 2017 with sam-
ple sizes between 145 and 901.
Three studies were assessed as having high quality
evidence and two studies were categorized as having
a satisfactory quality of evidence. Two studies were
cross-sectional,
45,46
one study used a cohort design
41
andonestudyusedacase-controldesign.
44
Figure S2 (supplementary material) indicates that
the calculated pooled effect size is 0.60 for the impact
of sex partner on reporting the borrowing of already
used syringes among PWID. The confidence interval
was 0.11 through 1.10 indicating a notable but not
significant association between the effect of sex part-
ner on the borrowing of used syringes among PWID.
Although the heterogeneity is 88.8%, the low number
of sex partners has a limited impact on risk behaviors
among PWID (OR, 0.60; 95% CI, 0.11–1.10).
Impact of HIV testing on borrowing of needles
and syringes among PWID
Three studies
39,44,51
examined the relationship
between HIV testing and borrowing of needles
Table 2. Characteristics of studies investigating factors associated with injecting risky behaviors among people who inject drugs.
Authors Country Year Sample size Study design
Reported
risky behaviors
Quality assessment
criteria
Bozinoff et al. [1] Canada 2017 505 Cohort Borrowing and Lending Good
Hartgers et al. [2] Netherlands 1989 145 Cohort Borrowing Satisfactory
Fisher et al. [3] Canada 2002 653 Not applicable Borrowing Good
Huo and Ouellet [4] U.S.A 2007 901 Cohort Borrowing and Lending Good
Jenness et al. [5] U.S.A 2011 500 Cross section Borrowing Satisfactory
Kerr et al. [6] Canada 2010 1228 Cohort Borrowing and Lending Good
Rachlis et al. [7]. Canada 2010 620 Cohort Borrowing Good
Kerr et al. [7] Thailand’s 2011 240 Cross section Borrowing Good
Strathdee et al. [8] Canada 1997 154 case-control Borrowing Satisfactory
Hartgers et al. [9] Netherlands 1992 125 Cross section Borrowing Satisfactory
Belanger et al. [10] Canada 2002 459 Cross section Borrowing and Lending Good
Kral et al. [11] U.S.A 2004 531 Cross section Lending Good
Rezaie et al. [12]. Iran 2016 500 Cross section Lending Good
Laktin and Forman [13] U.S.A 2001 741 Cross section Lending Satisfactory
1. Bozinoff N, Wood E, Dong HR, Richardson L, Kerr T, DeBeck K: Syringe Sharing Among a Prospective Cohort of Street-Involved Youth: Implications for
Needle Distribution Programs. Aids and Behavior 2017, 21(9):2717-2725.
2. Hartgers C, Buning EC, Vansanten GW, Verster AD, Coutinho RA: THE IMPACT OF THE NEEDLE AND SYRINGE-EXCHANGE PROGRAM IN AMSTERDAM ON
INJECTING RISK BEHAVIOR. Aids 1989, 3(9):571-576.
3. Fisher DG, Harbke CR, Canty JR, Reynolds GL: Needle and syringe cleaning practices among injection drug users. Journal of drug education 2002,
32(2):167-178.
4. Huo DZ, Ouellet LJ: Needle exchange and injection-related risk behaviors in Chicago - A longitudinal study. Jaids-Journal of Acquired Immune Deficiency
Syndromes 2007, 45(1):108-114.
5. Jenness SM, Hagan H, Liu K-L, Wendel T, Murrill CS: Continuing HIV Risk in New York City Injection Drug Users: The Association of Syringe Source and
Syringe Sharing. Substance Use & Misuse 2011, 46(2-3):192-200.
6. Kerr T, Small W, Buchner C, Zhang R, Li K, Montaner J, Wood E: Syringe Sharing and HIV Incidence Among Injection Drug Users and Increased Access
to Sterile Syringes. American Journal of Public Health 2010, 100(8):1449-1453.
7. Rachlis B, Lloyd-Smith E, Small W, Tobin D, Stone D, Li K, Wood E, Kerr T: Harmful Microinjecting Practices Among a Cohort of Injection Drug Users in
Vancouver Canada. Substance Use & Misuse 2010, 45(9):1351-1366.
8. Strathdee SA, Patrick DM, Archibald CP, Ofner M, Cornelisse GA, Rekart M, Schechter MT, Oshaughnessy MV: Social determinants predict needle-sharing
behavior among injection drug users in Vancouver, Canada. Addiction 1997, 92(10):1339-1347.
9. Hartgers C, van Ameijden EJ, van den Hoek JA, Coutinho RA: Needle sharing and participation in the Amsterdam Syringe Exchange program among
HIV-seronegative injecting drug users. Public health reports (Washington, DC : 1974) 1992, 107(6):675-681.
10. Belanger D, Godin G, Alary M, Noel L, Cote N, Claessens C: Prediction of needle sharing among injection drug users. Journal of Applied Social
Psychology 2002, 32(7):1361-1378.
11. Kral AH, Anderson R, Flynn NM, Bluthenthal RN: Injection risk behaviors among clients of syringe exchange programs with different syringe dispensa-
tion policies. Journal of acquired immune deficiency syndromes (1999) 2004, 37(2):1307-1312.
12. Rezaie F, Noroozi A, Armoon B, Farhoudian A, Massah O, Sharifi H, Ahounbar E, Khodadost M, Mohammadi F, Barkhordar N: Social determinants and
hepatitis C among people who inject drugs in Kermanshah, Iran: socioeconomic status, homelessness, and sufficient syringe coverage. Journal of
Substance Use 2016:1-5.
13. Latkin CA, Forman VL: Patterns of needle acquisition and sociobehavioral correlates of needle exchange program attendance in Baltimore, Maryland,
U.S.A. Journal of acquired immune deficiency syndromes (1999) 2001, 27(4):398-404.
6 O. REZAEI ET AL.
and syringes among PWID. Three studies were
conducted in high-income countries. The dates
the studies were published ranged from 1989 to
2010, and the sample sizes were between 154 and
1228. One had a high quality of evidence and
two studies were categorized as having a satisfac-
tory quality of evidence. Two studies used a
cohort design
39,51
and one study used a case-con-
trol design. As illustrated in Figure S3 (supple-
mentary material) HIV testing is not associated
with the borrowing of used needles and syringes.
The heterogeneity is 88.4% and the pooled effect
size implies no significant association (OR, 0.70;
95% CI, 0.16–1.24).
Impact of frequency of injection on borrowing
of needles and syringes among PWID
Figure S4 (supplementary material) presents the
possible association between frequency of injec-
tion and the borrowing of syringes among
PWID. Reduced frequency of injection has a
positive impact on the borrowing of syringes
among PWID. The heterogeneity statistic is 0%,
and the pooled effect size implies no significant
association, although the confidence interval is
wide and ranges between 0.79 and 3.16 (OR,
1.98; 95% CI, 0.79–3.16).
Impact of type of drug used (methamphetamine
use versus others) on lending of needles and
syringes among PWID
Figure 4 shows the association between type of
drug used (methamphetamine use versus others)
and the lending of used syringes among PWID.
Two studies examined the relationship between
type of drug used (methamphetamine use versus
others) and the lending of used syringes among
PWID. Two studies
41,51
were conducted in high-
income countries. The dates of studies ranged
from 2007 to 2010, and the sample sizes were
between 901 and 1228. Both studies used a
cohort design and were assessed as having a high
quality level of evidence.
Figure 2. Forest plot of binge drug use on borrowing of syringe showing the OR and 95% CI by sub-groups.
JOURNAL OF ADDICTIVE DISEASES 7
Figure 3. Forest plot of type of drug used (methamphetamine vs others) on borrowing of syringe showing the OR and 95% CI by
sub-groups.
Figure 4. Forest plot of type of drug used (methamphetamine vs others) on lending syringe showing the OR and 95% CI by
sub-groups.
8 O. REZAEI ET AL.
Methamphetamine use was positively associ-
ated with the lending of syringes among PWID.
The pooled effect size is about 1.39 with a confi-
dence interval between 1.33 and 1.64. The overall
heterogeneity was 60.1%. Those PWID who
reported methamphetamine use were 1.39 times
more likely to report the lending of used needles
and syringes (OR, 1.39; 95% CI, 1.13–1.64).
Impact of homelessness on lending of needles and
syringes among PWID
Figure 5 is the forest plot outlining the effect of
homelessness on the reporting of lending used
needles and syringes among PWID.
Three studies examined the relationship
between homelessness and the lending of previ-
ously used needles and syringes among PWID.
Two studies
38,47
were conducted in high-income
countries and one of them in an upper middle
income country.
48
The dates of studies ranged
from 2004 to 2017, and the sample sizes were
between 500 and 531. Three studies were assessed
as high quality. Two studies were cross sectional
and one used a cohort design.
As illustrated in Figure 5, homelessness was
positively associated with the lending of syringes
among PWID. The heterogeneity statistics is
38.2%, and the pooled effect size implies an asso-
ciation, although the confidence interval is wide
(range between 1.27 and 2.51). Homeless PWID
were 1.89 times more likely to report the lending
of needles and syringes (OR, 1.89; 95%
CI, 1.27–2.51).
Impact of HIV status on lending of needles and
syringes among PWID
Figure 6 is the forest plot of the effect of HIV
status on lending of syringes among PWID.
Three studies
41,49,51
examined the relationship
between HIV status and of lending used needles
and syringes among PWID. Three studies were
conducted in high-income countries. The dates of
studies ranged from 2001to 2010, and the sample
sizes were between 741 and 1228. Three studies
were assessed as having a high quality of evi-
dence. Two studies used a cohort design and one
study used a cross section design.
As illustrated in Figure 6 current HIV positive
status has a negative impact on the lending of used
syringes among PWID. The heterogeneity statistic
is about 24.7%, and the pooled effect size implies
a relative neutral association. Those respondents
Figure 5. Forest plot of homelessness on lending syringes showing the OR and 95% CI by sub-groups.
JOURNAL OF ADDICTIVE DISEASES 9
who reported being currently HIV positive were
0.50 times less likely to lend already used needles
and syringes (OR, 0.50; 95% CI, 0.37–0.63).
To identify the publication bias, we used
Egger’s plot and this did not demonstrate
significant bias (P ¼0.08,) (Figure S5).
Discussion
This systematic review and meta-analysis shows
the key factors associated with injection-related
risk behaviors among PWID. The specific focus is
on the reporting of borrowing and/or lending of
already used injecting equipment. Fourteen studies
met the eligibility criteria of the study. Details of
the studies included are shown in Table 2. In our
analysis we investigated nine factors related to
injection-related risk taking among PWID. While
we found no significant relationship between age
and the borrowing of used syringes (pooled OR:
0.98; %95 CI: 0.93-1.03) previous research con-
ducted in Iran established that older PWID were
more likely to report lifetime syringe sharing.
54
Australian research has found older PWID report
lower levels of current injecting-related risk taking,
including the sharing of needles and syringes,
when compared to younger PWID
55
suggesting
that over time PWID can change their behaviors.
It is important to note evidence of PWID describ-
ing needle borrowing as a behavior which makes
them more socially connected to other PWID but
not necessarily regarding this sharing as ‘risky’.
56
A number of studies conducted in the late 1990s
found between 40-45% of PWID reported recent
borrowing of a used syringe.
57–59
These studies
identified a wide range of issues as related to
sharing behavior, including demographic charac-
teristics,
53
social dimension,
60
sexual behaviors,
61
injecting behaviors,
52
and the normalization of
sharing within injecting partnerships.
62
Other
studies found that being of younger age,
63–66
hav-
ing a shorter injection history,
64,67,68
and being in
a sexual relationship with other injectors
63,69,70
were commonly associated with the borrowing of
already used syringes. A Canadian longitudinal
cohort study of young injectors found that almost
40% (N¼191) of the sample reported either
syringe borrowing, syringe lending, or both over a
10 year period.
38
Similarly, an Iranian-based study
showed that 35.8% of PWID reported a lifetime
experience of needle and syringe sharing.
54
Recent
injecting drug use prevalence estimates showed
varied ages for PWID globally but noted evidence
for ageing populations of PWID particularly in
Figure 6. Forest plot of HIV status on lending syringes showing the OR and 95% CI by sub-groups.
10 O. REZAEI ET AL.
Europe, North America, and Australia.
1
Results
from a longitudinal cohort study with younger
injectors in San Francisco showed a positive rela-
tionship between receptive syringe sharing and
younger age.
71
Research with younger PWID sug-
gests they have less extensive experience with
injecting and that this may lead to re-use and shar-
ing of previously used syringes.
72–74
Our results
indicated a significant relationship between binge
drug use and the borrowing of syringes (pooled
OR: 1.39; %95 CI: 1.06-1.71). This finding is con-
sistent with previous studies which found that
cocaine injection (often used in binge sessions)
was significantly associated with increased odds of
becoming infected with HCV.
75–77
We also identified several related associations
with binge drug use, including syringe lending
and borrowing and HIV seroconversion. Public
health policy makers would do well to design
public health interventions to decrease vulnerabil-
ities related to binge drug use. The borrowing
and lending of syringes among PWID on a binge
may be due to the policies and regulations of cer-
tain NSP.
78
Clearly changing these policies and
regulations so as to ensure increased availability
of sterile syringes will decrease the negative pub-
lic health consequences associated with binge
injection drug use.
79
In line with the results of previous studies
showing frequent methamphetamine injection is
positively associated with syringe sharing
75,80
our
research further suggests that methamphetamine
use had a positive effect on the borrowing of nee-
dles and syringes (pooled OR: 1.50; %95CI: 1.22-
1.77). This finding is in line with the previously
published Australian research that linked fre-
quent cocaine injection to syringe sharing.
75
Our results related to drug specific HIV-risk
behaviors show that injection-related risk practices
(borrowing and lending of already used needles
and syringes) indicate another mode for possible
HIV transmission among methamphetamine
users.
81
Methamphetamine production has been
reported as highly profitable, easily concealed and
demand for the drug is growing.
82
Law enforce-
ment may have a partial influence on use
83
but will
never eliminate use and therefore, evidence-based
HIV prevention and drug treatment programs for
methamphetamine injectors are required to reduce
the most negative harms associated with its use.
84
Results of the current study showed no statistic-
ally significant correlation between having a cur-
rent sex partner who injects and the borrowing of
used syringes (pooled OR: 0.60; %95 CI: 0.11-1.01).
Gender and power dynamics for female PWID are
important risk factors for borrowing and lending
of used needles and syringes.
85
There is a great
deal of previous research highlighting that female
PWID who inject together with their sex partners
might be at higher risk primarily because they use
after and with the used equipment of their
partners.
44,63,77,80,86,87
Our study did not find a statistically significant
correlation between recent HIV testing and syr-
inge borrowing (pooled OR: 0.70; %95 CI: 0.16-
1.24). The present meta-analysis showed no sig-
nificant effect of frequency of injection on syr-
inge borrowing (pooled OR: 1.98; %95 CI: 0.79-
3.16). However, this contradicts results from
another study showing a positive association
between needle sharing and higher frequency of
injection,
88
one possible explanation for this dif-
ference could be the wide confidence intervals of
the studies.
HIV prevention interventions targeting PWID,
such as sterile syringe programs and evidence-based
treatment, should be up scaled and implemented for
methamphetamine usage.
89
NSPs are one of the most
important public-health interventions for BBV
prevention among PWID. These programs not only
supply sterile injecting equipment for active injectors,
but are also in a position to provide other prevention
materials(condomsandice-pipes),primary
health care, legal and social services, as well as drug
treatment all of which contribute to reducing the
marginalization of drug users.
90
Consistent with other studies
80,91
our results
showed that
92
use is positively associated with the
lending of syringes (pooled OR: 1.39; %95 CI:
1.13-1.64) and there is a significant association
between methamphetamine use and HIV risk
among PWID.
Our results indicate the need for continued
efforts to develop effective BBV prevention
programs and further research to better under-
stand the implications of increasing rates of
methamphetamine injection. There clearly remain
JOURNAL OF ADDICTIVE DISEASES 11
imposing structural factors that impact adequate
access to sterile syringes among PWID,
51,93
and
these together with the substantial stigma
experienced mean that peer-facilitated syringe
distribution may be beneficial and provide
necessary BBV prevention tools to PWID.
31
While access to sterile syringe distribution
services has improved across many countries,
more is needed to ensure these services are avail-
able for methamphetamine injectors specifically
as many programs were designed and developed
to work with PWID who inject opioids.
94
Our analysis found a statistically significant
relationship between syringe lending and syringe
borrowing and homelessness.
38,91
Unstable hous-
ing has a direct impact on the safe and secure
places where PWID can inject and it is more
common for them to report using in public set-
tings where they are at risk of arrest by police.
95
Public injecting has also been shown to be more
rushed, less safe and less hygienic.
96
PWID who
inject in public places are more likely to report
needle and syringe sharing than those who do
not use in public settings
28,97
and homelessness
has also been associated with drug injecting
98–102
other social vulnerabilities including poverty,
103
poor mental health,
99
and incarceration.
103
Qualitative research studies indicate that
homelessness is related with more drug use to
increase sleep or to stay awake, both of which
may increase opportunities for syringe sharing.
99
Also, homeless PWID have reported unstable
housing as a reason police use to harass them.
104
Our findings indicate an association between
homelessness and syringe sharing and point to
the need for policy interventions that improve
the accessibility of stable and affordable housing
and thereby reduce opportunities for syringe
sharing among PWID. As noted above the devel-
opment of one-stop-shop models for a range of
vulnerable PWID may prove to be the best way
of reducing overall harms.
There are limitations to this study that need to
be acknowledged and considered when conduct-
ing future research on this topic. First, a major
weakness was that some of the studies did not
provide sufficient information for inclusion in
the meta-analysis, for other studies there was no
response to author correspondence requesting
this information. With the number of included
studies we were conscious of the need to improve
the precision and estimations for our pooled OR.
A second limitation is that the studies were
observational meaning statistical measures
including “OR”and “RR”were less available.
The selected studies used a range of covariates
and different methods to develop their logistic
and linear models and performed univariate and
other multivariate approaches. The covariate clas-
sifications that contained education and income
levels were not consistent across studies. There
were few studies that directly included data on
lending and/or borrowing of syringes, so this gap
remains in the literature. Our results only present
the data that were reported in the articles.
Although understanding the relationship between
polydrug drug use, daily heroin use, incarceration
and alcohol use and increased lending and/or
borrowing of syringes are essential for the devel-
opment of appropriate prevention interventions,
only one of the included studies specifically
reports on the factors associated with lending
and/or borrowing syringes. For a number of the
papers cited in the discussion, the independent
variables were not borrowing or lending of
syringes. Instead syringe sharing in general is
used so we could not consider them as borrowing
or lending specifically. These differences in the
measurement of sharing between studies meant
that we could not include some studies in the
analysis. Moreover, the selected studies used
different logistic and linear models and applied
both univariate and other multivariate approaches
in their analysis. The covariate classifications that
were different between studies included educa-
tion, social support, and income levels. Therefore,
we specified some conditions to allow for the
integration of data and to conduct the meta-
analysis. A strength of our analysis is that the
time interval for study inclusion covered the
problems identified in a previous meta-analysis.
24
Conclusion
This systematic review and meta-analysis supports
the development of initiatives that reduce drug-
related harms including the establishment and
maintenance of sterile needle syringe programs.
27
12 O. REZAEI ET AL.
The data collected and reported suggest that pro-
gram developers and policymakers across all levels
of government should initiate and expand programs
that facilitate the distribution and collection of ster-
ile injecting equipment for PWID.
Declaration of interest
Ethical approval and consent to participate
Not applicable.
Consent for publication
Not applicable.
Availability of data and materials
The datasets used and/or analyzed during the
current study are available from the correspond-
ing author on reasonable request.
Competing interests
The authors declare that there are no conflicts
of interest.
Funding
This research did not receive any specific grant
from funding agencies in the public, commercial,
or nonprofit sector.
Authors’contributions
Study concept and design BA, AB and HGh.
Analysis and interpretation of data: EA, and FR:
Drafting the manuscript. MN, PH and AN:
Critical revision of the manuscript:OR. All
authors read and approved the final manuscript.
Acknowledgements
The authors would like to acknowledge the contributions of
Haedar Mohammadi to the work of this review of
the evidence.
Abbreviations
HCV hepatitis C virus;
PWID people who inject drugs;
BBVs blood borne viruses;
OR odds ratios;
CI: confidence interval;
PRISMA Protocols of Systematic Reviews and
Meta-Analyses;
NSPs needle syringe programs
ORCID
Bahram Armoon http://orcid.org/0000-0001-5467-9889
References
1. Degenhardt L, Peacock A, Colledge S, Leung J,
Grebely J, Vickerman P, Stone J, Cunningham EB,
Trickey A, Dumchev K, et al. Global prevalence of
injecting drug use and sociodemographic characteris-
tics and prevalence of HIV, HBV, and HCV in peo-
ple who inject drugs: a multistage systematic review.
Lancet Glob Health. 2017;5(12):e1192–e1207. doi:10.
1016/S2214-109X(17)30375-3.
2. Degenhardt L, Charlson F, Stanaway J, Larney S,
Alexander LT, Hickman M, Cowie B, Hall WD,
Strang J, Whiteford H, et al. Estimating the burden
of disease attributable to injecting drug use as a risk
factor for HIV, hepatitis C, and hepatitis B: findings
from the Global Burden of Disease Study 2013.
Lancet Infect Dis. 2016;16(12):1385–98. doi:10.1016/
S1473-3099(16)30325-5.
3. Noroozi A, Mirzazadeh A, Farhoudian A, Hajebi A,
Khankeh HR, Higgs P, Sharifi H, Armoon B,
Noroozi M. Impact of HIV status notification on
risk behaviors among men who inject drugs in
Kermanshah, West of Iran. J Res Health Sci. 2016;
16(3):116–21.
4. Noroozi M, Ahmadi S, Armoon B, Jorjoran
Shushtari Z, Sharhani A, Ahounbar E, Karimi S. e,
Rahmani A, Mokhayeri Y, Qorbani M, et al. Social
determinants associated with risky sexual behaviors
among men who inject drugs in Kermanshah,
Western Iran. J Subst Use. 2018;23(6):591–6. doi:10.
1080/14659891.2018.1459905.
5. Rezaie F, Noroozi A, Armoon B, et al. Social deter-
minants and hepatitis C among people who inject
drugs in Kermanshah, Iran: socioeconomic status,
homelessness, and sufficient syringe coverage. J
Subst Use. 2017;22(5):474–478.
6. Palmateer NE, Hutchinson SJ, Innes H, Schnier C,
Wu O, Goldberg DJ, Hickman M. Review and meta-
analysis of the association between self-reported
sharing of needles/syringes and hepatitis C virus
prevalence and incidence among people who inject
drugs in Europe. Int J Drug Policy. 2013;24(2):
85–100. doi:10.1016/j.drugpo.2012.08.006.
7. Pilarinos A, Kennedy MC, McNeil R, Dong H, Kerr
T, DeBeck K. The association between residential
eviction and syringe sharing among a prospective
JOURNAL OF ADDICTIVE DISEASES 13
cohort of street-involved youth. Harm Reduct J.
2017;14(1):24doi:10.1186/s12954-017-0150-5.
8. Cox J, Morissette C, De P, Tremblay C, Allard R,
Graves L, Stephenson R, Roy E. Access to sterile
injecting equipment is more important than aware-
ness of HCV status for injection risk behaviors
among drug users. Subst Use Misuse. 2009;44(4):
548–68. doi:10.1080/10826080802544349.
9. Bowden S, McCaw R, White P, Crofts N, Aitken C.
Detection of multiple hepatitis C virus genotypes in
a cohort of injecting drug users. J Viral Hepat. 2005;
12(3):322–4. doi:10.1111/j.1365-2893.2005.00592.x.
10. Herring BL, Page-Shafer K, Tobler LH, Delwart EL.
Frequent hepatitis C virus superinfection in injection
drug users. J Infect Dis. 2004;190(8):1396–403. doi:
10.1086/424491.
11. Smith BD, Jewett A, Burt RD, Zibbell JE, Yartel AK,
DiNenno E. “To share or not to share?”Serosorting by
hepatitis C status in the sharing of drug injection
equipment among NHBS-IDU2 participants?”JInfect
Dis. 2013;208(12):1934–42. doi:10.1093/infdis/jit520.
12. Bryant J, Treloar C. Risk practices and other charac-
teristics of injecting drug users who obtain injecting
equipment from pharmacies and personal networks.
Int J Drug Policy. 2006;17(5):418–24. doi:10.1016/j.
drugpo.2006.07.004.
13. DeP,CoxJ,BoivinJ-F,PlattRW,JollyAM.Social
network-related risk factors for bloodborne virus infec-
tions among injection drug users receiving syringes
through secondary exchange. J Urban Health. 2008;
85(1):77–89. doi:10.1007/s11524-007-9225-z.
14. Noroozi M, Noroozi A, Sharifi H, Harouni GG,
Marshall BDL, Ghisvand H, Qorbani M, Armoon B.
Needle and syringe programs and HIV-related risk
behaviors among men who inject drugs: a multilevel
analysis of two cities in Iran. Intj Behav Med. 2019;
26(1):50–8. doi:10.1007/s12529-018-9758-4.
15. Noroozi M, Rahimi E, Ghisvand H, Qorbani M,
Sharifi H, Noroozi A, Farhoudian A, Marshall BDL,
Jorjoran Shoshtari Z, Karimi SE, et al.
Decomposition of Economic Inequality in Needle
and Syringe Programs Utilization to its
Determinants among Men Who Inject Drugs in
Tehran using Blinder-Oaxaca Decomposition
Method. Subst Use Misuse. 2018;53(7):1170–6. doi:
10.1080/10826084.2017.1400567.
16. Bastos FI, Strathdee SA. Evaluating effectiveness of
syringe exchange programmes: current issues and
future prospects. Soc Sci Med. 2000;51(12):1771–82.
doi:10.1016/s0277-9536(00)00109-x.
17. Cao W, Treloar C. Comparison of needle and syr-
inge programme attendees and non-attendees from a
high drug-using area in Sydney, New South Wales .
Drug Alcohol Rev. 2006;25(5):439–44. doi:10.1080/
09595230600891282.
18. Armoon B, Noroozi M, Jorjoran Shushtari Z,
Sharhani A, Ahounbar E, Karimi S, Ahmadi S,
Farhoudian A, Rahmani A, Abbasi M, et al. Factors
associated with HIV risk perception among people
who inject drugs: findings from a cross-sectional
behavioral survey in Kermanshah, Iran. J Subst Use.
2018;23(1):63–6. doi:10.1080/14659891.2017.1348554.
19. Noroozi M, Ahounbar E, Karimi SE, Ahmadi S,
Najafi M, Bazrafshan A, Shushtari ZJ, Farhadi MH,
Higgs P, Rezaei F, et al. HIV Risk perception and
risky behavior among people who inject drugs in
Kermanshah, Western Iran. Int J Behav Med. 2017;
24(4):613–8. doi:10.1007/s12529-017-9634-7.
20. Bazrafshan MR, Noroozi M, Ghisvand H, Noroozi
A, Alibeigi N, Abbasi M, Higgs P, Armoon B.
Comparing injecting risk behaviors of long-term
injectors with new injectors in Tehran, Iran. Subst
Use Misuse. 2019;54(2):185–90. doi:10.1080/
10826084.2018.1491055.
21. Fernandes RM, Cary M, Duarte G, Jesus G, Alarc~
ao
J, Torre C, Costa S, Costa J, Carneiro AV.
Effectiveness of needle and syringe Programmes in
people who inject drugs –an overview of systematic
reviews. BMC Public Health. 2017;17(1):309doi:10.
1186/s12889-017-4210-2.
22. Abdul-Quader AS, Feelemyer J, Modi S, Stein ES,
Briceno A, Semaan S, Horvath T, Kennedy GE, Des
Jarlais DC. Effectiveness of structural-level needle/
syringe programs to reduce HCV and HIV infection
among people who inject drugs: a systematic review.
AIDS Behav. 2013;17(9):2878–92. doi:10.1007/
s10461-013-0593-y.
23. Aspinall EJ, Nambiar D, Goldberg DJ, Hickman M,
Weir A, Van Velzen E, Palmateer N, Doyle JS,
Hellard ME, Hutchinson SJ, et al. Are needle and
syringe programmes associated with a reduction in
HIV transmission among people who inject drugs: a
systematic review and meta-analysis. Int J Epidemiol.
2014;43(1):235–48. doi:10.1093/ije/dyt243.
24. Ksobiech K. A meta-analysis of needle sharing, lend-
ing, and borrowing behaviors of needle exchange
program attenders. AIDS Educ Prev. 2003;15(3):
257–68. doi:10.1521/aeap.15.4.257.23828.
25. Moradi-Joo M, Ghiasvand H, Noroozi M, Armoon
B, Noroozi A, Karimy M, Rostami A, Mirzaee MS,
Hemmat M. Prevalence of skin and soft tissue
infections and its related high-risk behaviors among
people who inject drugs: a systematic review and
meta-analysis. Journal of Substance Use. 2019;24(4):
350–60. doi:10.1080/14659891.2019.1572805.
26. Cross JE, Saunders CM, Bartelli D. The effectiveness
of educational and needle exchange programs: a
meta-analysis of HIV prevention strategies for inject-
ing drug users. Quality and Quantity. 1998;32(2):
165–80. [Mismatch] doi:10.1023/A:1004398707484.
27. Topp L, Iversen J, Baldry E, Maher L, CoA N,
Collaboration of Australian NSPs. Housing instabil-
ity among people who inject drugs: results from the
Australian needle and syringe program survey. J
14 O. REZAEI ET AL.
Urban Health. 2013;90(4):699–716. doi:10.1007/
s11524-012-9730-6.
28. ShamseerL,MoherD,ClarkeM,GhersiD,LiberatiA,
Petticrew M, Shekelle P, Stewart LA, the PRISMA-P
GroupPreferred reporting items for systematic review
and meta-analysis protocols (PRISMA-P) 2015:
elaboration and explanation. Bmj. 2015;349(jan02 1):
g7647–g7647. doi:10.1136/bmj.g7647.
29. Stroup DF, Berlin JA, Morton SC, Olkin I,
Williamson GD, Rennie D, Moher D, Becker BJ,
Sipe TA, Thacker SB, et al. Meta-analysis of observa-
tional studies in epidemiology: a proposal for report-
ing. Meta-analysis Of Observational Studies in
Epidemiology (MOOSE) groupJama. 2000;283(15):
2008–12. doi:10.1001/jama.283.15.2008.
30. Bayat A-H, Mohammadi R, Moradi-Joo M, Bayani A,
Ahounbar E, Higgs P, Hemmat M, Haghgoo A,
Armoon B. HIV and drug related stigma and risk-tak-
ing behaviors among people who inject drugs: a sys-
tematic review and meta-analysis. J Addict Dis. 2020;
38(1):71–83. doi:10.1080/10550887.2020.1718264.
31. Ghiasvand H, Bayani A, Noroozi A, Marshall BD,
Koohestani HR, Hemmat M, Mirzaee MS, Bayat AH,
Noroozi M, Ahounbar E, et al. Comparing injecting
and sexual risk behaviors of long-term injectors with
new injectors: A meta-analysis. J Addict Dis. 2018;
37(3-4):233–44. doi:10.1080/10550887.2019.1666622.
32. Landis JR, Koch GG. The measurement of observer
agreement for categorical data. biometrics. 1977;
33(1):159–74. doi:10.2307/2529310.
33. Stang A. Critical evaluation of the Newcastle-Ottawa
scale for the assessment of the quality of nonrandom-
ized studies in meta-analyses. Eur J Epidemiol. 2010;
25(9):603–5. doi:10.1007/s10654-010-9491-z.
34. Higgins JP, Green S. Cochrane handbook for system-
atic reviews of interventions. Vol 4: John Wiley &
Sons, Chichester, West Sussex, England,; 2011.
35. Hansen BT, Hukkelberg SS, Haldorsen T, Eriksen T,
Skare GB, Nygård M. Factors associated with non-
attendance, opportunistic attendance and reminded
attendance to cervical screening in an organized
screening program: a cross-sectional study of 12,058
Norwegian women. BMC Public Health. 2011;11(1):
264doi:10.1186/1471-2458-11-264.
36. Begg CB, Mazumdar M. Operating characteristics of a
rank correlation test for publication bias. Biometrics.
1994;50(4):1088–101. doi:10.2307/2533446.
37. Egger M, Smith GD, Schneider M, Minder C. Bias in
meta-analysis detected by a simple, graphical test.
BMJ. 1997;315(7109):629–34. doi:10.1136/bmj.315.
7109.629.
38. Bozinoff N, Wood E, Dong HR, Richardson L, Kerr
T, DeBeck K. Syringe sharing among a prospective
cohort of street-involved youth: implications for nee-
dle distribution programs. AIDS Behav. 2017;21(9):
2717–25. doi:10.1007/s10461-017-1762-1.
39. Hartgers C, Buning EC, Vansanten GW, Verster AD,
Coutinho RA. The impact of the needle and syringe-
exchange program in Amsterdam on injecting risk
behavior. AIDS. 1989;3(9):571–6.
40. Fisher DG, Harbke CR, Canty JR, Reynolds GL.
Needle and syringe cleaning practices among injec-
tion drug users. J Drug Educ. 2002;32(2):167–78.
doi:10.2190/2HMC-W575-5M2E-G3LU.
41. Huo DZ, Ouellet LJ. Needle exchange and injection-
related risk behaviors in Chicago: a longitudinal
study. J Acquir Immune Defic Syndr. 2007;45(1):
108–14. doi:10.1097/QAI.0b013e318050d260.
42. Jenness SM, Hagan H, Liu K-L, Wendel T, Murrill
CS. Continuing HIV risk in New York city injection
drug users: the association of syringe source and syr-
inge sharing. Subst Use Misuse. 2011;46(2-3):
192–200. doi:10.3109/10826084.2011.521467.
43. Rachlis B, Lloyd-Smith E, Small W, Tobin D, Stone
D, Li K, Wood E, Kerr T. Harmful microinjecting
practices among a cohort of injection drug users in
Vancouver Canada. Subst Use Misuse. 2010;45(9):
1351–66. doi:10.3109/10826081003767643.
44. Strathdee SA, Patrick DM, Archibald CP, Ofner M,
Cornelisse PG, Rekart M, Schechter MT,
O’Shaughnessy MV. Social determinants predict nee-
dle-sharing behaviour among injection drug users in
Vancouver, Canada. Addiction. 1997;92(10):1339–47.
45. Hartgers C, van Ameijden EJ, van den Hoek JA,
Coutinho RA. Needle sharing and participation in the
Amsterdam Syringe Exchange program among HIV-
seronegative injecting drug users. Public Health Reports
(Washington, DC: 1974). 1992;107(6):675–81.
46. Belanger D, Godin G, Alary M, Noel L, Cote N,
Claessens C. Prediction of needle sharing among injec-
tion drug users. J Appl Social Pyschol. 2002;32(7):
1361–78. doi:10.1111/j.1559-1816.2002.tb01441.x.
47. Kral AH, Anderson R, Flynn NM, Bluthenthal RN.
Injection risk behaviors among clients of syringe
exchange programs with different syringe dispensa-
tion policies. J Acquir Immune Defic Syndr (1999).
2004;37(2):1307–12.
48. Rezaie F, Farhadi MH, Farhoudian A, Najafi M,
Bazrafshan A, Higgs P, Mohammadi Shahboulagh F,
Ranjbar M, Vameghi M, Abbasi M, et al. Access to
needle and syringe programs and the relationship to
equipment sharing among people who inject drugs
in Kermanshah, Iran. J Subst Use. 2017;22(4):
397–402. doi:10.1080/14659891.2016.1227384.
49. Latkin CA, Forman VL. Patterns of needle acquisi-
tion and sociobehavioral correlates of needle
exchange program attendance in Baltimore,
Maryland, U.S.A. J Acquir Immune Defic Syndr
(1999). 2001;27(4):398–404.
50. Kerr T, Small W, Buchner C, Zhang R, Li K,
Montaner J, Wood E. Syringe sharing and HIV inci-
dence among injection drug users and increased
JOURNAL OF ADDICTIVE DISEASES 15
access to sterile syringes. Am J Public Health. 2010;
100(8):1449–53. doi:10.2105/AJPH.2009.178467.
51. Kerr T, Fairbairn N, Hayashi K, Suwannawong P,
Kaplan K, Zhang R, Wood E. Difficulty accessing
syringes and syringe borrowing among injection drug
users in Bangkok, Thailand. Drug Alcohol Rev. 2010;
29(2):157–61. doi:10.1111/j.1465-3362.2009.00093.x.
52. Hartgers C, Van Ameijden E, Van Den Hoek J,
Coutinho RA. Needle sharing and participation in
the Amsterdam Syringe Exchange program among
HIV-seronegative injecting drug users. Public Health
Rep. 1992;107(6):675–81.
53. Bealanger D, Godin G, Alary M, Bernard PM. Factors
Explaining the Intention to Use Condoms Among
Injecting Drug Users Participating in a Needle-
Exchange Program. J Appl Social Pyschol. 2002;32(5):
1047–63. doi:10.1111/j.1559-1816.2002.tb00255.x.
54. Rafiey H, Narenjiha H, Shirinbayan P, Noori R,
Javadipour M, Roshanpajouh M, Samiei M, Assari S.
Needle and syringe sharing among Iranian drug
injectors. Harm Reduct J. 2009;6(1):21doi:10.1186/
1477-7517-6-21.
55. Horyniak D, Dietze P, Degenhardt L, Higgs P,
McIlwraith F, Alati R, Bruno R, Lenton S, Burns L.
The relationship between age and risky injecting
behaviours among a sample of Australian people
who inject drugs. Drug Alcohol Depend. 2013;
132(3):541–6. doi:10.1016/j.drugalcdep.2013.03.021.
56. Smyth BP, Barry J, Keenan E. Syringe borrowing
persists in Dublin despite harm reduction interven-
tions. Addiction. 2001;96(5):717–27. doi:10.1046/j.
1360-0443.2001.9657177.x.
57. Strathdee SA, Patrick DM, Currie SL, Cornelisse
PGA, Rekart ML, Montaner JSG, Schechter MT, Oʼ
shaughnessy MV. Needle exchange is not enough:
lessons from the Vancouver injecting drug use study.
AIDS. 1997;11(8):F59–F65. doi:10.1097/00002030-
199708000-00001.
58. Gossop M, Griffiths P, Powis B, Williamson S,
Fountain J, Strang J. Continuing drug risk behaviour:
shared use of injecting paraphernalia among London
heroin injectors. AIDS Care Psychol Care. 1997;9(6):
651–60. doi:10.1080/09540129750124687.
59. Stark K, Bienzle U, Vonk R, Guggenmoos-Holzmann
I. History of syringe sharing in prison and risk of
hepatitis B virus, hepatitis C virus, and human
immunodeficiency virus infection among injecting
drug users in Berlin. Int J Epidemiol. 1997;26(6):
1359–66. doi:10.1093/ije/26.6.1359.
60. Neaigus A, Friedman SR, Jose B, et al. High-risk per-
sonal networks and syringe sharing as risk factors
for HIV infection among new drug injectors. J
Acquir Immune Defic Syndr. 1996;11(5):499–509.
61. Klee H, Morris J. The role of needle exchanges in
modifying sharing behaviour: cross-study compari-
sons 1989–1993. Addiction. 1995;90(12):1635–45.
doi:10.1111/j.1360-0443.1995.tb02834.x.
62. Salmaso S, Conti S, Sasse H. Drug use and HIV-1
infection: report from the Second Italian Multicenter
Study. J Acquir Immune Defic Syndr. 1991;4(6):607–13.
63. Carruthers S, Loxley W. Hepatitis C and young drug
users: are they about to join the epidemic? Aust J
Public Health. 1995;19(4):421–4. doi:10.1111/j.1753-
6405.1995.tb00398.x.
64. Cassin S, Geoghegan T, Cox G. Young injectors: a
comparative analysis of risk behaviour. Ir J Med Sci.
1998;167(4):234–7. doi:10.1007/BF02937420.
65. Fennema JS, Ameijden EJ, Hoek A, Coutinho RA.
Young and recent-onset injecting drug users are at
higher risk for HIV. Addiction. 1997;92(11):1457–65.
doi:10.1111/j.1360-0443.1997.tb02867.x.
66. Saxon AJ, Calsyn DA, Jackson TR. Longitudinal
changes in injection behaviors in a cohort of injec-
tion drug users. Addiction. 1994;89(2):191–202. doi:
10.1111/j.1360-0443.1994.tb00878.x.
67. Peters A, Davies T, Richardson A. Multi-site samples
of injecting drug users in Edinburgh: prevalence and
correlates of risky injecting practices . Addiction. 1998;
93(2):253–67. doi:10.1046/j.1360-0443.1998.9322539.x.
68. Stark K, Muller R, Wirth D, Bienzle U, Pauli G,
Guggenmoos-Holzmann I. Determinants of HIV
infection and recent risk behaviour among injecting
drug users in Berlin by site of recruitment.
Addiction. 1995;90(10):1367–75. doi:10.1111/j.1360-
0443.1995.tb03554.x.
69. Baker A, Kochan N, Dixon J, Wodak A, Heather N.
HIV risk-taking behaviour among injecting drug
users currently, previously and never enrolled in
methadone treatment. Addiction. 1995;90(4):545–54.
doi:10.1111/j.1360-0443.1995.tb02189.x.
70. Kemp R, Miller J, Lungley S, Baker M. Injecting
behaviours and prevalence of hepatitis B, C and D
markers in New Zealand injecting drug user popula-
tions. The NZ Med J. 1998;111(1060):50–3.
71. Evans JL, Hahn JA, Page-Shafer K, et al. Gender dif-
ferences in sexual and injection risk behavior among
active young injection drug users in San Francisco
(the UFO Study). J Urban Health. 2003;80(1):
137–46. doi:10.1093/jurban/jtg137.
72. Beletsky L, Heller D, Jenness SM, Neaigus A, Gelpi-
Acosta C, Hagan H. Syringe access, syringe sharing,
and police encounters among people who inject
drugs in New York City: a community-level perspec-
tive. Int J Drug Policy. 2014;25(1):105–11. doi:10.
1016/j.drugpo.2013.06.005.
73. KralAH,BluthenthalRN,ErringerEA,LorvickJ,Edlin
BR. Risk factors among IDUs who give injections to or
receive injections from other drug users. Addiction. 1999;
94(5):675–83. doi:10.1046/j.1360-0443.1999.9456755.x.
74. Tassiopoulos K, Bernstein J, Bernstein E. Age and
sharing of needle injection equipment in a cohort of
Massachusetts injection drug users: an observational
study. Addict Sci Clin Pract. 2013;8(1):20. doi:10.
1186/1940-0640-8-20.
16 O. REZAEI ET AL.
75. Maher L, Jalaludin B, Chant K, Kaldor J. Hepatitis C
among intravenous drug users. Epidemiology. 2005;
16(3):423.
76. Thomas DL, Vlahov D, Solomon L, Cohn S, Taylor
E, Garfein R, Nelson KE. Correlates of hepatitis C
virus infections among injection drug users.
Medicine (Baltimore)). 1995;74(4):212–20. doi:10.
1097/00005792-199507000-00005.
77. Thorpe LE, Ouellet LJ, Hershow R, Bailey SL,
Williams IT, Williamson J, Monterroso ER, Garfein
RS. Risk of hepatitis C virus infection among young
adult injection drug users who share injection equip-
ment. Am J Epidemiol. 2002;155(7):645–53. doi:10.
1093/aje/155.7.645.
78. Miller CL, Kerr T, Frankish JC, Spittal PM, Li K,
Schechter MT, Wood E. Binge drug use independ-
ently predicts HIV seroconversion among injection
drug users: implications for public health strategies.
Subst Use Misuse. 2006;41(2):199–210. doi:10.1080/
10826080500391795.
79. Noroozi M, Marshall BDL, Noroozi A, Armoon B,
Sharifi H, Farhoudian A, Ghiasvand H, Vameghi M,
Rezaei O, Sayadnasiri M, et al. Do needle and syr-
inge programs reduce risky behaviours among peo-
ple who inject drugs in Kermanshah City, Iran? A
coarsened exact matching approach. Drug Alcohol
Rev. 2018;37:S303–S308. doi:10.1111/dar.12646.
80. Hayashi K, Wood E, Suwannawong P, Kaplan K, Qi
J, Kerr T. Methamphetamine injection and syringe
sharing among a community-recruited sample of
injection drug users in Bangkok, Thailand. Drug
Alcohol Depend. 2011;115(1-2):145–9. doi:10.1016/j.
drugalcdep.2010.10.018.
81. Wood E, Tyndall MW, Spittal PM, Li K, Anis AH,
Hogg RS, Montaner JSG, O’Shaughnessy MV,
Schechter MT. Impact of supply-side policies for
control of illicit drugs in the face of the AIDS and
overdose epidemics: investigation of a massive her-
oin seizure. CMAJ. 2003;168(2):165–9.
82. Stoneberg DM, Shukla RK, Magness MB. Global
methamphetamine trends: an evolving problem. Int
Crim Just Rev. 2018;28(2):136–61. doi:10.1177/
1057567717730104.
83. Cunningham JK, Liu LM. Impacts of federal precur-
sor chemical regulations on methamphetamine
arrests. Addiction. 2005;100(4):479–88. doi:10.1111/j.
1360-0443.2005.01032.x.
84. Kerr T, Wood E, Grafstein E, Ishida T, Shannon K,
Lai C, Montaner J, Tyndall MW. High rates of pri-
mary care and emergency department use among
injection drug users in Vancouver. J Public Health
(Oxf)). 2005;27(1):62–6. doi:10.1093/pubmed/fdh189.
85. El-Bassel N, Shaw SA, Dasgupta A, Strathdee SA.
People who inject drugs in intimate relationships: it
takes two to combat HIV. Curr HIV/AIDS Rep.
2014;11(1):45–51. doi:10.1007/s11904-013-0192-6.
86. Wood E, Tyndall MW, Spittal PM, Li K, Hogg RS,
Montaner JSG, O’Shaughnessy MV, Schechter MT.
Factors associated with persistent high-risk syringe
sharing in the presence of an established needle
exchange programme. AIDS. 2002;16(6):941–3. doi:
10.1097/00002030-200204120-00021.
87. Frischer M, Haw S, Bloor M, Goldberg D, Green S,
McKeganey N, Covell R. Modeling the behavior and
attributes of injecting drug users: a new approach to
identifying HIV risk practices. Int J Addict. 1993;
28(2):129–52. doi:10.3109/10826089309039619.
88. Colledge S, Leung J, Larney S, Peacock A, Grebely J,
Hickman M, Cunningham E, Trickey A, Stone J,
Vickerman P, et al. Frequency of injecting among
people who inject drugs: a systematic review and
meta-analysis. Int J Drug Policy. 2020;76:102619doi:
10.1016/j.drugpo.2019.102619.
89. Ballester J, Valentine G, Sofuoglu M.
Pharmacological treatments for methamphetamine
addiction: current status and future directions.
Expert Rev Clin Pharmacol. 2017;10(3):305–14. doi:
10.1080/17512433.2017.1268916.
90. Harris M, Rhodes T. Hepatitis C treatment access
and uptake for people who inject drugs: a review
mapping the role of social factors. Harm Reduct J.
2013;10(1):7doi:10.1186/1477-7517-10-7.
91. Krawczyk C, Molitor F, Ruiz J, et al.
Methamphetamine use and HIV risk behaviors
among heterosexual men—preliminary results from
five northern California counties, December
2001–November 2003. MMWR. 2006;55(10):273–7.
92. Rawson RA, Gonzales R, Pearce V, Ang A, Marinelli-
Casey P, Brummer J, Methamphetamine Treatment
Project Corporate AuthorsMethamphetamine
dependence and human immunodeficiency virus risk
behavior. J Subst Abuse Treat. 2008;35(3):279–84. doi:
10.1016/j.jsat.2007.11.003.
93. Perngmark P, Vanichseni S, Celentano DD. The
Thai HIV/AIDS epidemic at 15 years: sustained nee-
dle sharing among southern Thai drug injectors.
Drug Alcohol Depend. 2008;92(1-3):183–90. doi:10.
1016/j.drugalcdep.2007.07.014.
94. Zule WA, Desmond DP. An ethnographic compari-
son of HIV risk behaviors among heroin and meth-
amphetamine injectors. Am J Drug Alcohol Abuse.
1999;25(1):1–23. doi:10.1081/ada-100101843.
95. Walsh C, Hubley AM, To MJ, Norena M,
Gadermann A, Farrell S, Hwang SW, Palepu A. The
effect of forensic events on health status and housing
stability among homeless and vulnerably housed
individuals: A cohort study. PloS One. 2019;14(2):
e0211704doi:10.1371/journal.pone.0211704.
96. Corneil TA, Kuyper LM, Shoveller J, Hogg RS, Li K,
Spittal PM, Schechter MT, Wood E. Unstable hous-
ing, associated risk behaviour, and increased risk for
HIV infection among injection drug users. Health
JOURNAL OF ADDICTIVE DISEASES 17
Place. 2006;12(1):79–85. doi:10.1016/j.healthplace.
2004.10.004.
97. Wagner KD, Simon-Freeman R, Bluthenthal RN.
The association between law enforcement encounters
and syringe sharing among IDUs on skid row: a
mixed methods analysis. AIDS Behav. 2013;17(8):
2637–43. doi:10.1007/s10461-013-0488-y.
98. Aidala A, Cross JE, Stall R, Harre D, Sumartojo E.
Housing status and HIV risk behaviors: implications
for prevention and policy. AIDS Behav. 2005;9(3):
251–65. doi:10.1007/s10461-005-9000-7.
99. Briggs D, Rhodes T, Marks D, Kimber J, Holloway
G, Jones S. Injecting drug use and unstable housing:
scope for structural interventions in harm reduction.
Drugs: education, Prevention and Policy. 2009;16(5):
436–50. doi:10.1080/09687630802697685.
100. Hunt N, Lloyd C, Kimber J, Tompkins C. Public
injecting and willingness to use a drug consumption
room among needle exchange programme attendees
in the UK. Int J Drug Policy. 2007;18(1):62–5. doi:
10.1016/j.drugpo.2006.11.018.
101. Neaigus A, Friedman SR, Curtis R, Des Jarlais DC,
Furst RT, Jose B, Mota P, Stepherson B, Sufian M,
Ward T, et al. The relevance of drug injectors’social
and risk networks for understanding and preventing
HIV infection. Soc Sci Med. 1994;38(1):67–78. doi:
10.1016/0277-9536(94)90301-8.
102. Sharifi H, Mirzazadeh A, Noroozi A, Marshall BDL,
Farhoudian A, Higgs P, Vameghi M, Mohhamadi
Shahboulaghi F, Qorbani M, Massah O, et al.
Patterns of HIV risks and related factors among peo-
ple who inject drugs in Kermanshah, Iran: a latent
class analysis. J Psychoactive Drugs. 2017;49(1):
69–73. doi:10.1080/02791072.2016.1262568.
103. Bourgois P. The moral economies of homeless her-
oin addicts: confronting ethnography, HIV risk, and
everyday violence in San Francisco shooting encamp-
ments. Subst Use Misuse. 1998;33(11):2323–51. doi:
10.3109/10826089809056260.
104. Rachlis BS, Wood E, Zhang R, Montaner JS, Kerr T.
High rates of homelessness among a cohort of
street-involved youth. Health Place. 2009;15(1):10–7.
doi:10.1016/j.healthplace.2008.01.008.
18 O. REZAEI ET AL.