M-J Milloy 1,2 , T Kerr 1,3 , J Montaner 1,3 , E Wood 1,3

1. Dose-response relationship between incarceration and non-adherence to HAART among injection drug users in a Canadian setting M-J Milloy1,2, T Kerr1,3, J Montaner1,3, E Wood1,3 1. BC Centre for Excellence in HIV/AIDS, St. Paul’s Hospital, Vancouver, BC, Canada; 2. School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada; 3. Department of Medicine, University of British Columbia, Vancouver, BC, Canada

2. INTRODUCTION • Incarceration: Opportunity to engage individuals in HIV care? • 10% of all HIV+ individuals in US incarcerated ≥ 1 time/year1 • Clinical trials demonstrated effectiveness of DOT interventions in prisons2,3 • Spaulding et al., 2009. PLoS ONE. • Altice et al., 2001. JAIDS. • Babudieri et al., 2000. JAMA.

3. INTRODUCTION • Effect of incarceration on adherence among IDU remains equivocal • Incarcerated associated with greater risk of non-suppression1 and discontinuation2 • Effect of long-term patterns of incarceration, release and re-incarceration on HIV treatment remains undetermined Palepu et al., 2003. J Urban Health. Kerr et al., 2005. AIDS Care.

4. OBJECTIVE To estimate the effect of the cumulative burden of incarceration on non-adherence to ART among a long-running cohort of community-recruited HIV-seropositive individuals who use injection drugs

5. METHODS: Sample • AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS): • Ongoing prospective cohort recruited using community outreach in Vancouver’s Downtown Eastside (DTES) • Eligibility: HIV+, ≥18 year old, injection drug use in previous month, informed consent • Current study restricted to ART-exposed

6. METHODS: Data • Every six months, participants respond to interviewer-administered questionnaire • Behavioural data including drug use, incarceration, housing, etc. • Linkage to Drug Treatment Programme • Comprehensive ART dispensation records • HIV clinical monitoring (CD4, HIV RNA load)

7. METHODS: Measures • Outcome of interest: Non-adherence to prescribed ART • Non-adherence: < 95% days dispensed of all days eligible in previous six months • Validated measure based on prescription refill • Adherence not confounded by financial ability given universal free access in BC

8. METHODS: Measures • Primary explanatory: Burden of incarceration • Incarceration event: Overnight or longer in youth detention, local jail, regional prison or federal penitentiary • Measured longitudinally at each follow-up • Cumulative sum converted into factor: • Zero events (Reference); • 1 – 2 incarceration events; • 3 – 5 incarceration events; • > 5 incarceration events

9. METHODS: Analysis • Multivariate modeling: • Generalised linear mixed effects • Including primary explanatory variable (incarceration) and possible confounders: Illicit drug use, housing, socio-demographics, CD4, HIV RNA pVL • Model built using Greenland et. al’s a priori stepwise backwards procedure

10. RESULTS: Sample • May 1996 to Sept 2009: 490 ART-exposed individuals recruited • 201 (41%) women and 192 (39%) Aboriginal ancestry • 2220 person-years of follow-up • Median follow-up: 29 months (Inter-quartile range [IQR]: 0 – 64)

11. RESULTS: Incarceration • Incarceration during study period • 1156 incarceration events among 271(55%) participants • Crude incarceration rate: 53 per 100 person-years (95% Confidence Interval [CI]: 50 – 56 per 100) • Median # incarceration events among incarcerated: 3 (IQR: 1 – 6)

14. DISCUSSION • Cumulative burden of incarceration a strong predictor of non-adherence • Dose-dependent relationship between incarceration and non-adherence • Increasing number of incarceration cycles present elevating barrier to adherence • Finding considers effect of incarceration within course of HIV disease among IDU

15. DISCUSSION • Prison-related barriers to adherence1 • Short-term interruptions common in intake and post-release periods • Disruptions caused by transitions between correctional/non-correctional settings • Lack of capacity for HIV care among prison medical staff • HIV-related stigma among prisoners 1. Small et al., 2009. AIDS Care.

16. DISCUSSION • HIV treatment efforts among IDU should directly address incarceration1 • Reform prison health care to improve access and adherence to ART • Reduce exposure to incarceration through community diversion 1. Maru et al., 2007. Lancet ID.

17. DISCUSSION • Time to consider a risk environment for HIV disease progression? • Risk environment framework1: HIV transmission risk produced by individual, social, enviromental and structural factors • Increasing evidence of importance of social, structural and environmental context in producing adherence among IDU 1. Rhodes et al., 2005. Soc Sci Med.

18. DISCUSSION • Study limitations: • ACCESS not a random sample of HIV-positive IDU; results may not be generalizable to other settings and other correctional systems • Incarceration not randomly assigned; observed association may be under influence of unmeasured confounding

19. CONCLUSION • Dose-dependent relationship between cumulative burden of incarceration and non-adherence to ART • Finding illuminates structural-level barrier to adherence among IDU • Efforts to deliver HIV treatment to IDU must consider role of incarceration

20. ACKNOWLEDGEMENTS • ACCESS participants • Deborah Graham, Tricia Collingham, Caitlin Johnston, Steve Kain, Calvin Lai for their research and administrative assistance • The ACCESS study is supported by United States National Institutes of Health (R01DA021525) and Canadian Institutes of Health Research (MOP-79297, RAA-79918) • Dr. Kerr is supported by the Michael Smith Foundation for Health Research and the Canadian Institutes of Health Research • Mr. Milloy is supported by the Canadian Institutes of Health Research