COMPARING INJECTION RISK BEHAVIORS AMONG INDIVIDUALS WITH AND WITHOUT ACCESS TO NEEDLE AND SYRINGE EXCHANGEASSESSING THE IMPACT OF NASCENT HARM REDUCTION EFFORTS IN MALAYSIA

ALEXANDER R. BAZAZIALEXEI ZELENEV

JEANNIA J. FUADEEBA KAMARULZAMAN

FREDERICK L. ALTICEYALE SCHOOL OF MEDICINE, YALE SCHOOL OF PUBLIC HEALTH

UNIVERSITY OF MALAYA CENTRE OF EXCELLENCE FOR RESEARCH IN AIDS

BACKGROUND• Numerous studies show that needle and syringe

exchange programs (NSEPs) reduce injection risk behaviors and transmission of blood-borne viruses; not associated with increased injection frequency

• Recommended as one of nine interventions in the WHO comprehensive package for people who inject drugs (PWIDs)

• NSEP was first introduced in KL in 2006 after Malaysia did not meet Millennium Development Goal 6, and has since expanded nationwide

Des Jarlais 2013; Watters 1994; Hartgers 1989; WHO 2012; Kamarulzaman 2009

CHALLENGES TO EVALUATING NSEPSelection bias in observational studies:

• Individuals at higher risk for HIV are more likely to use NSEPs.

Predictors of initial engagement in NSEPs:• Homelessness, high-risk injection practices

Predictors of retention in NSEPs: • Frequent injection, high-risk injection practices

Randomized trials rarely conducted due to logistical and ethical issues.

Fisher 2002; Hagan 2000; Hahn 1997

SPECIFIC AIMTo estimate the difference in HIV risk behaviors that can be attributed to NSEPs by matching similar individuals with and without access to NSEPs from a sample of PWIDs in Klang Valley, Malaysia.

DATA DESCRIPTION• Cross-sectional sample of 460 PWIDs recruited using

respondent-driven sampling in 2010• Recruitment at 3 locations in Kuala Lumpur and

surrounding areas in the Klang Valley• “Treatment” variable was defined as receiving most

injection equipment from a NSEP• Outcomes:

• Receptive sharing of injection equipment in prior 30 days

• Binary (any sharing vs. no sharing) and count data (frequency)

• Syringe barrel and needle reuse in prior 30 days• Count data (frequency)

SYRINGE NEEDLE

ANALYTIC METHODS• Parameter of interest: “Average effect of treatment on the treated”

• What is the estimated effect of NSEPs on the HIV risk behaviors of people who accessed NSEPs?

• First, each participant accessing NSEP was matched 1:4 to the most similar participants not accessing NSEPs.• Participants were matched on correlates of accessing NSEP that

were not likely influenced by NSEP: • 1) recruitment site, 2) injections per day, 3) daily injection, and 4)

unstable housing • Nearest neighbor matching used, Abadie & Imbens robust standard

errors calculated.

• Then, examined differences in HIV risk behaviors between each participant accessing NSEP and the average of their four matched participants (“controls”)

Fisher 2002; Hagan 2000; Hahn 1997; Abadie & Imbens 2004

SAMPLE DESCRIPTION (N=460)

“Treatment”Received most injection equipment from NSEP, prior 6 months 35%

Outcomes, prior 30 daysAny receptive needle or syringe sharing 48%

Any receptive syringe sharing 20%Any receptive needle sharing 44%

Mean # episodes of needle or syringe sharing (SD) 21.4 (37.7)Mean # syringe uses before discarding (SD) 16.6 (28.6) Mean # needle uses before discarding (SD) 7.8 (13.7)

Sample is predominantly Malay (90%) men (96%) who had been injecting for >5 years (82%). All used opioids: (heroin) (94%); methadone (33%); buprenorphine (18%). Also, benzodiazepines (33%), methamphetamine (32%), and alcohol (18%).

Outcome, previous 30 days NSEP Users

Inferred Outcome if

No Access to NSEP

Est. Avg. Difference in

Outcome Attributable

to NSEP

95% CI P-value

Any receptive needle or syringe sharing

55% 86% -31% -39 to -20% <0.001

Any receptive syringe sharing 10% 13% -3% -15 to 11% 0.734

Any receptive needle sharing 53% 85% -32% -41 to -22% <0.001

Mean total episodes of needle and syringe sharing

36 episodes 50 episodes -14 episodes -26 to -4 0.006

Mean times syringe used before discarding 5 uses 30 uses -25 uses -37 to -20 <0.001

Mean times needle used before discarding 3 uses 11 uses -8 uses -16 to -5 <0.001

RESULTS

CONCLUSIONS• There was a significant reduction (31%) in sharing of

needles, but not syringe barrels, among PWIDs accessing NSEP services. • Syringe sharing is less common than needle sharing,

and syringes are reused many more times than detachable needles.

• NSEPs reduce reuse and therefore circulation time of both needles and syringes, potentially lowering the risk of transmission of blood-borne viruses.

• Despite limitations in the study design and availability of measures related to accessing NSEPs, these data provide empirical support for expansion of NSEPs in Malaysia

ACKNOWLEDGMENTSRESEARCH ASSISTANTS

• Ezra Akbar• Nur Afiqah Salleh• Mohd Azizi• Hisyamuddin Nawi• Syazwani Zakaria• Amran Hashim• Nur Ainna Amira• Elfaridz Mohd. Radzi

CLINIC DIRECTORS• Ishak Khafidz, M.D.• Mohd Ghanni, M.D.• L. Ting, M.D.

• IKHLAS• Persuatan Insaf Murni Malaysia• KAWAN

NEEDLE EXCHANGES

• Theresa Anthony, CERiA• Rusdi Rashid, M.D. UMCAS• Hussain Habil, M.D. UMCAS• Malaysian AIDS Council

OTHER ASSISTANCE

• University Malay High Impact Research Grant

• Yale Downs Fellowship• Yale OIMSE, OSR

FUNDING

ALL THE PARTICIPANTS WHO GAVE GENEROUSLY OF THEIR TIME.

Outcome, previous 30 days NSEP Users Not NSEP User Crude

DifferenceEst. Difference Due to NSEP

Any receptive needle or syringe sharing

55% 44% +11% -31%

Any receptive syringe sharing 10% 25% -15% -3%

Any receptive needle sharing 53% 39% +14% -32%

Mean total episodes of needle and syringe sharing

36 episodes 13 episodes +22 episodes -14 episodes

Mean times syringe used before discarding 5 uses 23 uses -18 uses -25 uses

Mean times needle used before discarding 3 uses 10 uses -7 uses -8 uses

APPENDIX (1): CRUDE AND ADJUSTED DIFFERENCES IN OUTCOMES

Variable NSEP Users Not NSEP User

Recruitment site

Kajang 30.7% 25.3%

Kampung Baru 65.0% 7.1%

Shah Alam 4.3% 67.7%

Daily injection 97.6% 87.9%

Injections per day, mean 3.7 injections 3.1 injections

Unstable housing 21.5% 14.1%

APPENDIX (2): MATCHING VARIABLES