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

1. Spaulding et al., 2009. PLoS ONE.2. Altice et al., 2001. JAIDS.3. 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

1. Palepu et al., 2003. J Urban Health.2. 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)

12

13

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