UBC Faculty Research and Publications

Homelessness and adherence to antiretroviral therapy among a cohort of HIV-infected injection drug users Palepu, Anita; Milloy, M-J; Kerr, Thomas; Zhang, Ruth; Wood, Evan Jun 1, 2011

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata


52383-Palepu_A_et_al_Homelessness_adherence_antiretroviral.pdf [ 166.97kB ]
JSON: 52383-1.0360661.json
JSON-LD: 52383-1.0360661-ld.json
RDF/XML (Pretty): 52383-1.0360661-rdf.xml
RDF/JSON: 52383-1.0360661-rdf.json
Turtle: 52383-1.0360661-turtle.txt
N-Triples: 52383-1.0360661-rdf-ntriples.txt
Original Record: 52383-1.0360661-source.json
Full Text

Full Text

Journal of Urban Health: Bulletin of the New York Academy of Medicine, Vol. 88, No. 3doi:10.1007/s11524-011-9562-9* 2011 The Author(s). This article is published with open access at Springerlink.comHomelessness and Adherence to AntiretroviralTherapy among a Cohort of HIV-Infected InjectionDrug UsersABSTRACT Homelessness is prevalent among HIV-infected injection drug users (IDU)and may adversely affect access and adherence to antiretroviral therapy (ART).There are limited descriptions of the effect of homelessness on adherence to ART inlong-term cohorts of HIV-infected IDU. We used data from a community-recruitedprospective cohort of HIV-infected IDU, including comprehensive ART dispensationrecords, in a setting where HIV care is free. We examined the relationship betweenthe homelessness measured longitudinally, and the odds of ≥95% adherence to ARTusing generalized estimating equations logistic regression modeling adjusting forsociodemographics, drug use, and clinical variables. Between May 1996 andSeptember 2008, 545 HIV-infected IDU were recruited and eligible for the presentstudy. The median follow-up duration was 23.8 months (IQR 8.5–91.6 months)contributing 2,197 person-years of follow-up. At baseline, homeless participantswere slightly younger (35.8 vs. 37.9 years, p=0.01) and more likely to inject heroinat least daily (37.1% vs. 24.6%. p=0.004) than participants who had housing. Themultivariate model revealed that homelessness (adjusted odds ratio [AOR] 0.66; 95%CI: 0.53–0.84) and frequent heroin use (AOR 0.40; 95% CI: 0.30–0.53) weresignificantly and negatively associated with ART adherence, whereas methadonemaintenance was positively associated (AOR 2.33; 95% CI: 1.86–2.92). Sub-optimalART adherence was associated with homelessness and daily injection heroin useamong HIV-infected IDU. Given the survival benefit of ART, it is critical to developand evaluate innovative strategies such as supportive housing and methadonemaintenance to address these risk factors to improve adherence.KEYWORDS Homeless persons, HIV/AIDS, antiretroviral therapy, adherenceINTRODUCTIONDespite dramatic advances in antiretroviral therapy (ART) resulting in improvedHIV treatment outcomes and survival,1–4 HIV-infected injection drug users (IDU)appear to have derived less benefit than other HIV-infected populations.5–7 Thereare a myriad of reasons ranging from barriers to accessing ART7,8 to decreasedadherence due to ongoing substance use9–12 and inadequate integration of addictionPalepu, Kerr, and Wood are with the Department of Medicine, University of British Columbia, Vancouver,BC, Canada; Palepu is with the Centre for Health Outcomes and Evaluation Sciences, Vancouver, BC,Canada; Milloy and Wood are with the School of Population and Public Health, University of BritishColumbia, Vancouver, BC, Canada; Zhang is with the British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada.Correspondence: Anita Palepu, 620B-1081 Burrard Street, Vancouver, BC V6Z 1Y6, Canada. (E-mail:anita@hivnet.ubc.ca)545Anita Palepu, M-J Milloy, Thomas Kerr, Ruth Zhang,and Evan Woodtreatment with HIV care.13–15 Another contributing factor may be the physical andsocial environments16,17 where a significant proportion of IDUs experience unstablehousing or homelessness.18–20Individuals who are unstably housed or homeless have a substantially increasedHIV/AIDS infection rate compared to persons who are housed.21 Homeless personsalso have higher risks of serious morbidity and mortality, with the most frequentlyreported causes of death being related to violence, HIV/AIDS, and substancemisuse.22–26 Furthermore, homeless persons living with HIV have been found to beless likely to access and receive optimal regular HIV care.16,27–29 This may alsorelated to healthcare associated barriers, given that prescribing physicians may beless likely to prescribe ART to these patients, although Bangsberg et al.30demonstrated that providers inaccurately estimated ART adherence compared tostructured patient report, which was more closely related to pill count among asample of homeless or unstably housed HIV-infected persons.Although homeless IDU have been reported to have lower rates of adherence toART, active drug use and homelessness are states that can change over time andlong-term evaluations of the impact of homelessness on adherence are limited andoften conducted in settings with financial barriers to care. Unlike previous studiesthat have examined homelessness and HIV treatment adherence, the context of thisstudy is one where HIV care is universally available and ART is provided at nocharge. Thus, we used the data derived from a longstanding community-based cohort ofHIV-infected IDU with detailed data on housing status and drug use behaviors todetermine the longitudinal impact of homelessness on adherence to ART.METHODSData for these analyses was derived from the AIDS Care Cohort to evaluateExposure to Survival Services (ACCESS), an ongoing prospective observationalcohort of HIV-infected illicit drug users in Vancouver, Canada. The methods for thisstudy have been previously described.8,31,32 In brief, beginning in May 1996,participants were recruited through snowball sampling and extensive street outreachin the city’s Downtown Eastside neighborhood, the local epicenter of drug-relatedHIV transmission. ACCESS eligibility criteria include: aged 18 years or older, HIV-infected, having used illicit drugs other than cannibinoids in the previous month,and having provided written informed consent. At baseline and every 6-monthfollow-up interview, participants answer a standardized interviewer-administeredquestionnaire, are examined by a study nurse and provide blood samples forserologic analysis. The information on sociodemographic, drug uses and otherbehavioral characteristics gathered at each interview is augmented with data on HIVcare and treatment outcomes from the British Columbia Centre for Excellence inHIV/AIDS Drug Treatment Programme. This province-wide, centralized antiretro-viral therapy dispensary and HIV/AIDS monitoring lab provides a completeprospective profile of CD4 cell counts, plasma HIV-1 RNA viral load, anddispensation of specific antiretroviral agents for each participant.8,31,32MeasuresIn the present study, we included all participants who were HIV-infected who had abaseline CD4 count and viral load measurement. The primary outcome of interestwas adherence to antiretroviral therapy. As in previous studies using this validatedand confidential pharmacy dispensation data,32–34 we measured adherence toPALEPU ET AL.546therapy in each 6-month period as a ratio of the number of days ARTwas dispensedover the number of days an individual was eligible for ART, and defined adherenceas equal to or greater than 95% adherence to ART during this period.33 The clinicalutility of this measure and its reliable prediction of virological suppression10,32–36and survival32,33 has been previously shown. The primary explanatory variable,homelessness, was defined as living on the street or having no fixed address in theprevious 6 months, which corresponded with the timeline of our primary outcome,ART adherence variable.We also considered other explanatory variables that might confound therelationship between homelessness and ART adherence. These included demo-graphic and socioeconomic characteristics such as age (per year older), gender(female vs. male), Aboriginal ancestry (yes vs. no), educational attainment (Ghighschool diploma vs. ≥ high school diploma), and legal employment (yes vs. no). Legalemployment referred to having salaried or temporary work at any time in theprevious 6 months. We also included the individual-level behavioral variables:injection cocaine use (≥daily vs. Gdaily), injection heroin use (≥daily vs. Gdaily),injection methamphetamine use (≥daily vs. Gdaily), and inhalation crack cocaine use(≥daily vs. Gdaily). We also included current use of methadone maintenancetherapy. These variables were time-updated, referred to the 6-month period prior tothe interview, and were consistent with previous analyses.32,37 Clinical variablesincluded were the baseline CD4+ cell count (per 100 cells/mm3) and HIV-1 RNAplasma viral load (per log10). For both measures, we used the mean of all availableobservations in the previous 6 months; if none were available, we used the mostrecent observation. Plasma HIV-1 RNA was measured using the Roche AmplicorMonitor assay (Roche Molecular Systems, Mississauga, Canada). We also includedthe year of the baseline interview to account for any cohort effects in ARTprescribing.Statistical AnalysisWe first compared the baseline characteristics of the study sample stratified byhomelessness, using the chi-squared test for categorical variables and the Wilcoxonrank-sum test for continuous variables. We then examined the bivariate relation-ships between adherence and all explanatory variables over the study period usinggeneralized estimating equations logistic regression models employing an exchange-able working correlation matrix.38,39 This form of regression modeling was used toaccount for the correlation between covariates gathered over time from the sameindividual, and to estimate the independent effect of homelessness on the likelihoodof adherence to ART within each individual. There were 93 (17%) subjects whonever accessed ART during the follow-up period and they were categorized as beingnon-adherent to ART. To account for possible confounding and calculate the besteffect estimate, we constructed a multivariate model using an a priori definedmodeling strategy suggested by Greenland et al.40 First, we fit a full model includingthe primary explanatory and all secondary explanatory variables. Using a manualstepwise approach, we constructed reduced models, each with one variable removedfrom the full set of secondary explanatory variables. Comparing the value of thecoefficient for the primary explanatory in the full model and each of the reducedmodels, we removed the secondary explanatory corresponding to the smallestrelative change. We continued this process until the maximum change from the fullmodel exceeded 5%. Several authors have successfully used this technique toHOMELESSNESS AND ANTIRETROVIRAL THERAPY ADHERENCE TO ANTIRETROVIRAL THERAPY 547estimate the independent relationship between an outcome of interest and a selectedexplanatory variable.40–42 We also examined selected interaction terms.RESULTSBetween May 1996 and April 2008, there were 545 HIV-infected individuals whowere eligible for the present study. The median follow-up duration was 23.8 months(IQR 8.5–91.6 months) contributing to 2,197 person-years of follow-up. Thecharacteristics of participants who were homeless at baseline are presented inTable 1. There were 143 (26.2%) IDU who were homeless at baseline. There wereno significant differences at baseline between the participants who were homelessand those who were not, other than that they were slightly younger (35.8 years vs.37.9 years, p=0.01) and that they were more likely to inject heroin at least daily(37.1% vs. 24.6%. p=0.004).During the study period, there were 1,186 (26.6%) observations that were 95%adherent, out of 4,460 total observations. Table 2 presents the bivariate associationbetween each explanatory variable on ART adherence over the study period.Participants who were homeless were less likely to be adherent to ART (odds ratio[OR] 0.62; 95% CI: 0.50–0.77). Female sex, lower educational attainment, frequentalcohol use, and injection drug use were negatively associated with ART adherence,whereas older age, methadone maintenance therapy, and time since the baselineinterview were positively associated with adherence to ART.The multivariate model result is depicted in Figure 1 and illustrates that afteradjustment, homelessness (adjusted odds ratio [AOR] 0.66; 95% CI: 0.53–0.84) andfrequent heroin use (AOR 0.40; 95% CI: 0.30–0.53) were significantly andnegatively associated with ART adherence adjusting for baseline CD4 count andbaseline plasma viral load. Methadone maintenance therapy was positivelyassociated with ART adherence (AOR 2.33; 95% CI: 1.86–2.92). There were nosignificant interactions.DISCUSSIONIn this long-term prospective study of HIV-infected IDU, we found that homelessnessand at least daily heroin use were negatively associated with ART adherence,whereas methadone maintenance was positively associated with adherence to ART.It has been previously shown that HIV-infected IDU who are able to achieve the95% level of adherence derive the clinical benefits of treatment through HIV-1 RNAviral suppression and CD4 cell count rise.10,43A number of studies have also found that ART adherence is negativelyassociated with ongoing drug use.9,11,12,36 These studies have emphasized theimportance of addressing addiction issues for HIV-infected IDU to optimize HIVtreatment outcomes. Lucas et al.44 recently reported a small randomized controlledtrial comparing clinic-based buprenorphine-naloxone (BUP) versus off-site referralfor opiate treatment for HIV-infected opioid-dependent patients and found thatintegrating BUP in the clinic setting increased access to addiction treatment andimproved substance abuse treatment outcomes. Methadone maintenance therapyhas also been shown to improve ART adherence and HIV treatment outcomes invariety of settings.34,37,45,46Homelessness in and of itself represents a significant structural risk factor forincreased morbidity and mortality,22,23,25,47 and for HIV-infected drug and alcoholPALEPU ET AL.548users who are homeless, their existing vulnerabilities are further heightened.48Homelessness among HIV-infected IDU may affect ART adherence through amultitude of mechanisms, including poor access to regular meals and water, lack ofa fixed daily routine, no place to store the medication, lack of privacy, and stigma, asTABLE 1 Selected sociodemographic, behavioral, and clinical characteristics at baseline,stratified by homelessness in ACCESS (n=545 participants)CharacteristicHomelessnessORa 95% CIb p ValueYes No143 (26.2) 402 (73.8)AgeMedian (IQR) 35.8 (29.1–42.3) 37.9 (31.8–43.9) 0.97 0.95–0.99 0.01GenderMale 95 (66.4) 246 (61.2) 1.00Female 48 (33.6) 156 (38.8) 0.80 0.53–1.19 0.266Aboriginal ancestryNo 96 (67.1) 264 (65.7) 1.00Yes 47 (32.9) 138 (34.4) 0.94 0.62–1.40 0.751Educational attainment≥ High school diploma 124 (86.7) 345 (85.8) 1.00GHigh school diploma 19 (13.3) 57 (14.2) 0.93 0.53–1.62 0.791Formal employmentNo 115 (80.4) 350 (87.1) 1.00Yes 28 (19.6) 52 (12.9) 1.64 0.99–2.72 0.054Frequent alcohol useGDaily 129 (90.2) 348 (86.6) 1.00≥Daily 14 (9.8) 54 (13.4) 0.70 0.38–1.30 0.258Frequent crack cocaine useGDaily 100 (69.9) 313 (77.9) 1.00≥Daily 43 (30.1) 89 (22.1) 1.51 0.99–2.32 0.06Frequent cocaine injectionGDaily 92 (64.3) 261 (4.9) 1.00≥Daily 51 (35.7) 141 (35.1) 1.03 0.69–1.53 0.899Frequent heroin injectionGDaily 90 (62.9) 303 (75.4) 1.00≥Daily 53 (37.1) 99 (24.6) 1.80 1.20–2.71 0.004Frequent speedball injectionGDaily 123 (86.0) 344 (85.6) 1.00≥Daily 20 (14) 58 (14.4) 0.96 0.56–1.67 0.897Frequent crystal meth injectionGDaily 140 (97.9) 395 (98.3) 1.00≥Daily 3 (2.1) 7 (1.7) 1.21 0.31–4.74 0.727Current methadone maintenance therapyNo 100 (69.9) 276 (68.7) 1.00Yes 43 (30.1) 126 (31.3) 0.94 0.62–1.42 0.777CD4+ cell countMedian (IQR) 100 cells/mm3 3.5 (2.1–5.3) 3.4 (2.1–4.7) 1.04 0.96–1.12 0.532HIV-1 RNA viral loadMedian (IQR) per log10 4.3 (2.9–4.9) 4.2 (2.6–4.8) 1.06 0.92–1.23 0.472aOdds ratiob95% Confidence intervalHOMELESSNESS AND ANTIRETROVIRAL THERAPY ADHERENCE TO ANTIRETROVIRAL THERAPY 549TABLE 2 Bivariate GEE logistic regression analysis of explanatory variables and ART adherencein ACCESS (n=545 participants contributed to 4,460 observations)Characteristic ORa 95% CIb p ValueHomelessnesscNo 1.00Yes 0.62 0.50–0.77 G0.001Age(per year) 1.06 1.04–1.08 G0.001GenderMale 1.00Female 0.69 0.52–0.89 0.006Aboriginal ancestryNo 1.00Yes 0.97 0.74–1.28 0.84Formal employmentcNo 1.00Yes 1.11 0.87–1.41 0.40Educational attainment≥High school diploma 1.00GHigh school diploma 0.56 0.37–0.85 0.007Frequent alcohol usecGDaily 1.00≥Daily 0.64 0.47–0.86 0.004Frequent crack cocaine usecGDaily 1.00≥Daily 0.94 0.78–1.13 0.51Frequent cocaine use, injectioncGDaily 1.00≥Daily 0.48 0.40–0.57 G0.001Frequent heroin use, injectioncGDaily 1.00≥Daily 0.38 0.30–0.48 G0.001Frequent speedball use, injectioncGDaily 1.00≥Daily 0.34 0.25–0.48 G0.001Frequent methamphetamine use, injectioncGDaily 1.00≥Daily 0.70 0.44–1.14 0.15Methadone maintenance therapyNo 1.00Yes 2.44 2.01–2.96 G0.001CD4 cell countPer 100 cells/mm3 0.94 0.89–0.99 0.047Per log10 unit increase 0.54 0.48–0.60 G0.001GEE generalized estimating equationsaOdds ratiob95% Confidence intervalcRefers to the 6-month period prior to the interviewPALEPU ET AL.550well as concomitant psychiatric disorders.15 Given the complexity of managing theirhealth, it is not surprising that case management has been shown to be positivelyassociated with ART adherence and improved HIV treatment outcomes amonghomeless HIV-infected persons.49Directly administered ART or modified directly observed ART administrationamong HIV-infected IDU or persons with substance dependence have been evaluatedin randomized trials and have found improved adherence and HIV treatmentoutcomes.50–53 One study followed patients after the directly administered ARTintervention when they went to self-administration and found no difference in viralsuppression at 6 months after the end of the trial, suggesting that ongoing strategiesare required to maintain the initial benefit.54A focus on individual-level behaviors alone may not be effective in improvingART adherence, especially in the context of homelessness or unstable housing.Strategies that address broader determinants of health, such as housing, for thisvulnerable group are more likely to be effective in creating the social and physicalenvironments that reduce the ongoing risks for non-adherence and other HIV-riskbehavior.16,55 The Housing and Health randomized trial of the effects of HousingOpportunities for People with AIDS rental assistance on the health and risk behaviorof homeless and unstably housed HIV-infected persons was recently reported.56They noted a significant increase in stable housing status over time for both theintervention and control group; however, it was higher for the intervention group at18 months (82.5% vs. 50.6%, pG0.0001). In terms of health outcomes, there wasno difference between groups in the proportion non-adherent to ART or new uptakeof ART. The intervention group reported more appropriate medical care, had bettermental and physical health scores, and lower stress than the control group.56 Thepower to detect differences between groups was attenuated by the higher-than-expected movement into housing among the control group in this trial. In contrast,the Chicago Housing for Health Partnership randomized trial examined theeffect of a housing and case management program for hospitalized homelesspersons with HIV who were ready for discharge, and found that more of theintervention group were alive after 12 months and had CD4 counts ≥200 cells/mm3 (55% vs. 34%, p=0.04). Unfortunately, they do not report on ARTmedication adherence.57 The housing model used in this study was “HousingFirst”58,59 and there were no sobriety or treatment adherence requirements for theparticipants, unlike housing ready models.FIGURE 1. Multivariable logistic regression model using GEE of factors associated with 95%antiretroviral therapy adherence.HOMELESSNESS AND ANTIRETROVIRAL THERAPY ADHERENCE TO ANTIRETROVIRAL THERAPY 551Our study had limitations. The cohort was not a random sample of HIV-infected participants and this is not feasible as no registry of all HIV-infectedindividuals, particularly illicit drug users, exists. This may limit the generalizability ofour results to other settings. Our pharmacy refill measure may be an overestimation ofadherence in our sample as we do not know if the study participants ingested theirmedication, although the measure has proven to be a potent predictor of virologicsuppression and mortality among HIV-infected persons.32–34In summary, we found that over a quarter of our HIV-infected IDU werehomeless at baseline and that in our longitudinal analysis, homelessness andfrequent heroin use were negatively associated with ART adherence. Onlymethadone maintenance was positively associated with adherence. Given the highmorbidity and mortality associated with sub-optimal ART adherence, future studiesshould evaluate innovative interventions that strengthen the links betweensupportive housing and addiction treatment for HIV-infected IDU.ACKNOWLEDGMENTSThe authors thank the study participants for their contribution to the research aswell as current and past researchers and staff. We would specifically like to thankDeborah Graham, Tricia Collingham, Caitlin Johnston, and Steve Kain for theirresearch and administrative assistance, and Drs. Julio Montaner and Robert Hoggfor facilitating access to the British Columbia Centre for Excellence HIV/AIDS DrugTreatment Program data. The study was supported by the US National Institutes ofHealth (R01DA021525) and the Canadian Institutes of Health Research (MOP-79297, RAA-79918). Thomas Kerr is supported by the Michael Smith Foundationfor Health Research and the Canadian Institutes of Health Research (CIHR). M-JMilloy is supported by a doctoral research award from CIHR.Human participant protection. The ACCESS cohort is reviewed annually and hasbeen approved by the University of British Columbia/Providence HealthcareResearch Ethics Board.Funding support. The study was supported by the US National Institutes of Health(R01DA021525) and the Canadian Institutes of Health Research (MOP-79297,RAA-79918).OPEN ACCESS This article is distributed under the terms of the Creative CommonsAttribution Noncommercial License which permits any noncommercial use,distribution, and reproduction in any medium, provided the original author(s) andsource are credited.REFERENCES1. Hammer SM, Squires KE, Hughes MD, et al. A controlled trial of two nucleosideanalogues plus indinavir in persons with human immunodeficiency virus infection andCD4 cell counts of 200 per cubic millimeter or less. AIDS Clinical Trials Group 320 StudyTeam. NEJM. 1997; 337(11): 725–33.2. Mocroft A, Ledergerber B, Katlama C, et al. Decline in the AIDS and death rates in theEuroSIDA study: an observational study. Lancet. 2003; 362(9377): 22–9.PALEPU ET AL.5523. Hogg RS, Yip B, Chan KJ, et al. Rates of disease progression by baseline CD4 cell countand viral load after initiating triple-drug therapy. JAMA. 2001; 286(20): 2568–77.4. Palella FJ Jr, Delaney KM, Moorman AC, et al. Declining morbidity and mortality amongpatients with advanced human immunodeficiency virus infection. HIV Outpatient StudyInvestigators. NEJM. 1998; 338(13): 853–60.5. Vlahov D, Celentano DD. Access to highly active antiretroviral therapy for injection drugusers: adherence, resistance, and death. Cad Saúde Pública. 2006; 22(4): 705–18.6. Lert F, Kazatchkine MD. Antiretroviral HIV treatment and care for injecting drug users:an evidence-based overview. Int J Drug Policy. 2007; 18(4): 255–61.7. Wood E, Montaner JSG, Tyndall MW, Schechter MT, O_Shaughnessy MV, Hogg RS.Prevalence and correlates of untreated human immunodeficiency virus type 1 infectionamong persons who have died in the era of modern antiretroviral therapy. J Infect Dis.2003; 188(8): 1164–70.8. Strathdee SA, Palepu A, Cornelisse PG, et al. Barriers to use of free antiretroviral therapyin injection drug users. JAMA. 1998; 280(6): 547–9.9. Lucas GM, Griswold M, Gebo KA, Keruly J, Chaisson RE, Moore RD. Illicit drug useand HIV-1 disease progression: a longitudinal study in the era of highly activeantiretroviral therapy. Am J Epidemiol. 2006; 163(5): 412–20.10. Wood E,Montaner JS, Yip B, et al. Adherence and plasmaHIV RNA responses to highly activeantiretroviral therapy amongHIV-1 infected injection drug users.CMAJ. 2003; 169(7): 656–61.11. Lucas GM, Gebo KA, Chaisson RE, Moore RD. Longitudinal assessment of the effects ofdrug and alcohol abuse on HIV-1 treatment outcomes in an urban clinic. AIDS. 2002; 16(5): 767–74.12. Lucas GM, Cheever LW, Chaisson RE, Moore RD. Detrimental effects of continued illicitdrug use on the treatment of HIV-1 infection. J Acquir Immune Defic Syndr. 2001; 27(3):251–9.13. Krusi A, Wood E, Montaner J, Kerr T. Social and structural determinants of HAARTaccess and adherence among injection drug users. Int J Drug Policy. 2010; 21(1): 4–9.14. Wood E, Kerr T, Tyndall MW, Montaner JS. A review of barriers and facilitators of HIVtreatment among injection drug users. AIDS. 2008; 22(11): 1247–56.15. Douaihy AB, Stowell KR, Bui T, Daley D, Salloum I. HIV/AIDS and homelessness, part 2:treatment issues. AIDS Read. 2005; 15(11): 604–18.16. Wolitski RJ, Kidder DP, Fenton KA. HIV, homelessness, and public health: critical issuesand a call for increased action. AIDS Behav. 2007; 11(6 Suppl): 167–71.17. Galea S, Rudenstine S, Vlahov D. Drug use, misuse, and the urban environment. DrugAlcohol Rev. 2005; 24(2): 127–36.18. Kim C, Kerr T, Li K, et al. Unstable housing and hepatitis C incidence among injectiondrug users in a Canadian setting. BMC Public Health. 2009; 9(1): 270.19. Palepu A, Strathdee SA, Hogg RS, et al. The social determinants of emergency departmentand hospital use by injection drug users in Canada. J Urban Health. 1999; 76(4): 409–18.20. Strathdee SA, Patrick DM, Currie SL, et al. Needle exchange is not enough: lessons fromthe Vancouver injecting drug use study. AIDS. 1997; 11(8): F59–65.21. Culhane DP, Gollub E, Kuhn R, Shpaner M. The co-occurrence of AIDS andhomelessness: results from the integration of administrative databases for AIDSsurveillance and public shelter utilisation in Philadelphia. J Epidemiol CommunityHealth. 2001; 55(7): 515–20.22. Hwang SW. Mortality among men using homeless shelters in Toronto, Ontario. JAMA.2000; 283(16): 2152–7.23. Hwang SW, Lebow JM, Bierer MF, O_Connell JJ, Orav EJ, Brennan TA. Risk factors fordeath in homeless adults in Boston. Arch Intern Med. 1998; 158(13): 1454–60.24. Hwang SW, Orav EJ, O_Connell JJ, Lebow JM, Brennan TA. Causes of death in homelessadults in Boston. Ann Intern Med. 1997; 126(8): 625–8.HOMELESSNESS AND ANTIRETROVIRAL THERAPY ADHERENCE TO ANTIRETROVIRAL THERAPY 55325. Cheung AM, Hwang SW. Risk of death among homeless women: a cohort study andreview of the literature. CMAJ. 2004; 170(8): 1243–7.26. Morrison DS. Homelessness as an independent risk factor for mortality: results from aretrospective cohort study. Int J Epidemiol. 2009; 38(3): 877–83.27. Aidala AA, Lee G, Abramson DM, Messeri P, Siegler A. Housing need, housingassistance, and connection to HIV medical care. AIDS Behav. 2007; 11(6 Suppl): 101–15.28. Leaver CA, Bargh G, Dunn JR, Hwang SW. The effects of housing status on health-related outcomes in people living with HIV: a systematic review of the literature. AIDSBehav. 2007; 11(6 Suppl): 85–100.29. Kidder DP, Wolitski RJ, Campsmith ML, Nakamura GV. Health status, health care use,medication use, and medication adherence among homeless and housed people livingwith HIV/AIDS. Am J Public Health. 2007; 97(12): 2238–45.30. Bangsberg DR, Hecht FM, Clague H, et al. Provider assessment of adherence to HIVantiretroviral therapy. J Acquir Immune Defic Syndr. 2001; 26(5): 435–42.31. Wood E, Hogg RS, Bonner S, et al. Staging for antiretroviral therapy among HIV-infecteddrug users. JAMA. 2004; 292(10): 1175–7.32. Wood E, Hogg RS, Lima VD, et al. Highly active antiretroviral therapy and survival inHIV-infected injection drug users. JAMA. 2008; 300(5): 550–4.33. Wood E, Hogg RS, Yip B, et al. Effect of medication adherence on survival of HIV-infected adults who start highly active antiretroviral therapy when the CD4+ cell count is0.200 to 0.350 × 10(9) cells/L. Ann Intern Med. 2003; 139(10): 810–6.34. Palepu A, Tyndall MW, Joy R, et al. Antiretroviral adherence and HIV treatmentoutcomes among HIV/HCV co-infected injection drug users: the role of methadonemaintenance therapy. Drug Alcohol Depend. 2006; 84(2): 188–94.35. Low-Beer S, Yip B, O_Shaughnessy MV, Hogg RS, Montaner JS. Adherence to tripletherapy and viral load response. J Acquir Immune Defic Syndr. 2000; 23(4): 360–1.36. Palepu A, Tyndall M, Yip B, O_Shaughnessy MV, Hogg RS, Montaner JS. Impairedvirologic response to highly active antiretroviral therapy associated with ongoinginjection drug use. J Acquir Immune Defic Syndr. 2003; 32(5): 522–6.37. Uhlmann S, Milloy MJ, Kerr T, et al. Methadone maintenance therapy promotesinitiation of antiretroviral therapy among injection drug users. Addiction. 2010; 105(5):907–13.38. Zeger SL, Liang KY. Longitudinal data analysis for discrete and continuous outcomes.Biometrics. 1986; 42: 121–30.39. Liang KY, Zeger SY. Longitudinal data analysis using generalized linear models.Biometrika. 1986; 73: 13–22.40. Maldonado G, Greenland S. Simulation study of confounder-selection strategies. Am JEpidemiol. 1993; 138(11): 923–36.41. Marshall BD, Kerr T, Shoveller JA, Patterson TL, Buxton JA, Wood E. Homelessness andunstable housing associated with an increased risk of HIV and STI transmission amongstreet-involved youth. Health Place. 2009; 15(3): 753–60.42. Lima V, Fernandes K, Rachlis B, Druyts E, Montaner J, Hogg R. Migration adverselyaffects antiretroviral adherence in a population-based cohort of HIV/AIDS patients. SocSci Med. 2009; 68(6): 1044–9.43. Wood E, Montaner JS, Yip B, et al. Adherence to antiretroviral therapy and CD4 T-cellcount responses among HIV-infected injection drug users. Antivir Ther. 2004; 9(2): 229–35.44. Lucas GM, Chaudhry A, Hsu J, et al. Clinic-based treatment of opioid-dependent HIV-infected patients versus referral to an opioid treatment program: a randomized trial. AnnIntern Med. 2010; 152(11): 704–11.45. Avants SK, Margolin A, Warburton LA, Hawkins KA, Shi J. Predictors of nonadherenceto HIV-related medication regimens during methadone stabilization. Am J AddictAmerican. 2001; 10(1): 69–78.PALEPU ET AL.55446. Palepu A, Horton NJ, Tibbetts N, Meli S, Samet JH. Uptake and adherence to highlyactive antiretroviral therapy among HIV-infected people with alcohol and othersubstance use problems: the impact of substance abuse treatment. Addiction. 2004; 99(3): 361–8.47. Hwang SW, O_Connell JJ, Lebow JM, Bierer MF, Orav EJ, Brennan TA. Health careutilization among homeless adults prior to death. J Health Care Poor Underserved. 2001;12(1): 50–8.48. Walley AY, Cheng DM, Libman H, et al. Recent drug use, homelessness and increasedshort-term mortality in HIV-infected persons with alcohol problems. AIDS. 2008; 22(3):415–20.49. Kushel MB, Colfax G, Ragland K, Heineman A, Palacio H, Bangsberg DR. Casemanagement is associated with improved antiretroviral adherence and CD4+ cell countsin homeless and marginally housed individuals with HIV infection. Clin Infect Dis. 2006;43(2): 234–42.50. Macalino GE, Hogan JW, Mitty JA, et al. A randomized clinical trial of community-baseddirectly observed therapy as an adherence intervention for HAART among substanceusers. AIDS. 2007; 21(11): 1473–7.51. Tyndall MW, McNally M, Lai C, et al. Directly observed therapy programmes for anti-retroviral treatment amongst injection drug users in Vancouver: access, adherence andoutcomes. Int J Drug Policy. 2007; 18(4): 281–7.52. Altice FL, Maru DS, Bruce RD, Springer SA, Friedland GH. Superiority of directlyadministered antiretroviral therapy over self-administered therapy among HIV-infecteddrug users: a prospective, randomized, controlled trial. Clin Infect Dis. 2007; 45(6): 770–8.53. Conway B, Prasad J, Reynolds R, et al. Directly observed therapy for the management ofHIV-infected patients in a methadone program. Clin Infect Dis. 2004; 38(Suppl 5): S402–8.54. Maru DS, Bruce RD, Walton M, Springer SA, Altice FL. Persistence of virological benefitsfollowing directly administered antiretroviral therapy among drug users: results from arandomized controlled trial. J Acquir Immune Defic Syndr. 2009; 50(2): 176–81.55. Kidder DP, Wolitski RJ, Royal S, et al. Access to housing as a structural intervention forhomeless and unstably housed people living with HIV: rationale, methods, andimplementation of the housing and health study. AIDS Behav. 2007; 11(6 Suppl): 149–61.56. Wolitski RJ, Kidder DP, Pals SL, et al. Randomized trial of the effects of housingassistance on the health and risk behaviors of homeless and unstably housed people livingwith HIV. AIDS Behav. 2010; 14(3): 493–503.57. Buchanan D, Kee R, Sadowski LS, Garcia D. The health impact of supportive housing forHIV-positive homeless patients: a randomized controlled trial. Am J Public Health. 2009;99(Suppl 3): S675–80.58. Culhane D, Metraus S, Hadley T. Public service reductions associated with placement ofhomeless persons with severe mental illness in supportive housing. Hous Policy Debate.2002; 13: 107–62.59. Tsemberis S, Gulcur L, Nakae M. Housing First, consumer choice, and harm reductionfor homeless individuals with a dual diagnosis. Am J Public Health. 2004; 94(4): 651–6.HOMELESSNESS AND ANTIRETROVIRAL THERAPY ADHERENCE TO ANTIRETROVIRAL THERAPY 555


Citation Scheme:


Citations by CSL (citeproc-js)

Usage Statistics



Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            async >
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:


Related Items