Factors related to virologic failure among HIV-positive injecting drug users treated with combination antiretroviral therapy including two nucleoside reverse transcriptase inhibitors and nevirapine

Determining the Roles that Club Drugs, Marijuana, and Heavy Drinking Play in PrEP Medication Adherence Among Gay and Bisexual Men: Implications for Treatment and Research

Researchers have established that substance use interferes with anti-retroviral medication adherence among gay and bisexual men (GBM) living with HIV. There is limited parallel examination of pre-exposure prophylaxis (PrEP) adherence among HIV-negative GBM. We conducted retrospective 30-day timeline follow-back interviews and prospective semi-weekly diary data for 10 weeks with 104 PrEP-using GBM, half of whom engaged in club drug use (ketamine, ecstasy, GHB, cocaine, or methamphetamine)-generating 9532 days of data. Participants reported their day-by-day PrEP, club drug, marijuana, and heavy alcohol use (5 + drinks in one sitting). On average, club drug users were no more likely to miss a dose of PrEP than non-club drug users (M = 1.6 doses, SD = 3.0, past 30 days). However, we found that club drug use (at the event level) increased the odds of missing a dose on the same day by 55% and the next day (e.g., a "carryover effect") by 60%. Further, missing a dose on one day increased the odds of missing a dose the following day by eightfold. We did not identify an event-level effect of marijuana use or heavy drinking on PrEP adherence. Our data suggest club drug users could have greater protective effects from daily oral or long-acting injectable PrEP compared to a time-driven PrEP regimen because of the concurrence of club drug use and PrEP non-adherence.

Sociodemographic and clinical factors associated with the preference between NNRTIs and PIs for the initial treatment of HIV infection: Perfil-es study

The Perfil-es study demonstrated that, while non-nucleoside reverse transcriptase inhibitor (NNRTI)-based initial antiretroviral therapy (ART) is more frequently used in human immunodeficiency virus (HIV)-infected naïve patients, ritonavir-boosted protease inhibitors (PI/r)-based regimens are the preferred option in patients with advanced infectious stages or high baseline viral load. The present analysis focused on the second phase of the Perfil-es study, where sociodemographic and clinical data were retrospectively collected from patients starting NNRTI- or PI/r-based regimens in order to identify factors that could influence the choice of initial ART. Patients' characteristics were compared by both bivariate and multivariate analyses. A total of 642 patients were evaluated. The main transmission group was men who have sex with men (MSM) (48%), and 24% of patients were coinfected with hepatitis B or C. Patients with cardiovascular risk accounted for 56%, and 15% had a neuropsychiatric history. Anxiolytics (29%), antidepressants (18%) and methadone (18%) were the most frequent concomitant medications. The use of PI/r-based regimens was more frequent in older patients, childbearing potential women patients coinfected with hepatitis B or C, and those with cardiovascular risk and a neuropsychiatric history. The presence of a neuropsychiatric disorder (OR: 1.912; CI 95%: 1.146-3.191; p < .05) and the use of concomitant medication (OR: 1.736; CI 95%: 1.204-2.502; p < .01) were identified as independent factors associated with the selection of PI/r-based regimens. MSM sexual conduct was the only independent factor related to the selection of NNRTI-based ART (OR: 0.699; CI 95%: 0.504-0.970; p < .05). Neither the physicians' characteristics nor the geographical area where HIV patients were attended influenced the choice of ART. In conclusion, patients' comorbidity, pregnancy potential and lifestyle seem to influence the choice of ART. Neuropsychiatric comorbidity and concomitant medication, mainly related to this condition, appear to be associated with the use of PI/r-based initial ART while MSM seem more likely to receive NNRTI-based regimens in Spain.

Superior Effects of Antiretroviral Treatment among Men Who have Sex with Men Compared to Other HIV At-Risk Populations in a Large Cohort Study in Hunan, China

This study assesses association between CD4 level at initiation of antiretroviral treatment (ART) on subsequent treatment outcomes and mortality among people infected with HIV via various routes in Hunan province, China. Over a period of 10 years, a total of 7333 HIV-positive patients, including 553 (7.5%) MSM, 5484 (74.8%) heterosexuals, 1164 (15.9%) injection drug users (IDU) and 132 (1.8%) former plasma donors (FPD), were recruited. MSM substantially demonstrated higher initial CD4 cell level (242, IQR 167-298) than other populations (Heterosexuals: 144 IQR 40-242, IDU: 134 IQR 38-224, FPD: 86 IQR 36-181). During subsequent long-term follow up, the median CD4 level in all participants increased significantly from 151 cells/mm³ (IQR 43-246) to 265 cells/mm³ (IQR 162-380), whereas CD4 level in MSM remained at a high level between 242 and 361 cells/mm³. Consistently, both cumulative immunological and virological failure rates (10.4% and 26.4% in 48 months, respectively) were the lowest in MSM compared with other population groups. Survival analysis indicated that initial CD4 counts ≤ 200 cells/mm³ (AHR = 3.14; CI, 2.43-4.06) significantly contributed to HIV-related mortality during treatment. Timely diagnosis and treatment of HIV patients are vital for improving CD4 level and health outcomes.

Understanding the effects of different HIV transmission models in individual-based microsimulation of HIV epidemic dynamics in people who inject drugs

We investigated how different models of HIV transmission, and assumptions regarding the distribution of unprotected sex and syringe-sharing events ('risk acts'), affect quantitative understanding of HIV transmission process in people who inject drugs (PWID). The individual-based model simulated HIV transmission in a dynamic sexual and injecting network representing New York City. We constructed four HIV transmission models: model 1, constant probabilities; model 2, random number of sexual and parenteral acts; model 3, viral load individual assigned; and model 4, two groups of partnerships (low and high risk). Overall, models with less heterogeneity were more sensitive to changes in numbers risk acts, producing HIV incidence up to four times higher than that empirically observed. Although all models overestimated HIV incidence, micro-simulations with greater heterogeneity in the HIV transmission modelling process produced more robust results and better reproduced empirical epidemic dynamics.

HIV virological failure and drug resistance among injecting drug users receiving first-line ART in China

OBJECTIVE

To explore HIV virological failure and drug resistance among injecting drug users (IDUs) receiving first-line antiretroviral treatment (ART) in China.

DESIGN

A series of cross-sectional surveys from 2003 to 2012 from the Chinese National HIV Drug Resistance (HIVDR) Surveillance and Monitoring Network.

SETTING

China.

PARTICIPANTS

Data were analysed by the Chinese National (HIVDR) Surveillance and Monitoring Network from 2003 to 2012. Demographic, ART and laboratory data (CD4+ cell count, viral load and drug resistance) were included. Factors associated with virological failure were identified by logistic regression analysis.

RESULTS

929 of the 8556 individuals in the Chinese HIVDR database were IDUs receiving first-line ART. For these 929 IDUs, the median duration of treatment was 14 months (IQR 6.0-17.8). 193 of the 929 IDUs (20.8%) experienced virological failure (HIV viral load ≥1000 copies/mL). The prevalence of HIVDR among patients with virological failure was 38.9% (68/175). The proportion of patients with drug resistance to non-nucleoside reverse transcriptase inhibitor (NNRTIs), nucleoside reverse transcriptase inhibitor (NRTIs) and protease inhibitors (PIs) was 52.9%, 76.5% and 4.4%, respectively. Factors independently associated with virological failure include: ethnic minorities, junior high school education or less, farmers, self-reported missing doses in the past month, CD4 cell count at survey from 200 to 349 cells/mm(3) or from 0 to 199 cells/mm(3), and residence of Guangxi and Yunnan provinces.

CONCLUSIONS

The proportion of virological failure was high among IDUs receiving first-line ART in China. However, better treatment outcomes were observed in Guangxi and Yunnan, which indicates the importance of ART education and adherence to intervention, especially for patients who are farmers, minorities or have a poor educational background.

A complex systems approach to evaluate HIV prevention in metropolitan areas: preliminary implications for combination intervention strategies

BACKGROUND

HIV transmission among injecting and non-injecting drug users (IDU, NIDU) is a significant public health problem. Continuing propagation in endemic settings and emerging regional outbreaks have indicated the need for comprehensive and coordinated HIV prevention. We describe the development of a conceptual framework and calibration of an agent-based model (ABM) to examine how combinations of interventions may reduce and potentially eliminate HIV transmission among drug-using populations.

METHODOLOGY/PRINCIPAL FINDINGS

A multidisciplinary team of researchers from epidemiology, sociology, geography, and mathematics developed a conceptual framework based on prior ethnographic and epidemiologic research. An ABM was constructed and calibrated through an iterative design and verification process. In the model, "agents" represent IDU, NIDU, and non-drug users who interact with each other and within risk networks, engaging in sexual and, for IDUs, injection-related risk behavior over time. Agents also interact with simulated HIV prevention interventions (e.g., syringe exchange programs, substance abuse treatment, HIV testing) and initiate antiretroviral treatment (ART) in a stochastic manner. The model was constructed to represent the New York metropolitan statistical area (MSA) population, and calibrated by comparing output trajectories for various outcomes (e.g., IDU/NIDU prevalence, HIV prevalence and incidence) against previously validated MSA-level data. The model closely approximated HIV trajectories in IDU and NIDU observed in New York City between 1992 and 2002, including a linear decrease in HIV prevalence among IDUs. Exploratory results are consistent with empirical studies demonstrating that the effectiveness of a combination of interventions, including syringe exchange expansion and ART provision, dramatically reduced HIV prevalence among IDUs during this time period.

CONCLUSIONS/SIGNIFICANCE

Complex systems models of adaptive HIV transmission dynamics can be used to identify potential collective benefits of hypothetical combination prevention interventions. Future work will seek to inform novel strategies that may lead to more effective and equitable HIV prevention strategies for drug-using populations.

Social and structural factors associated with HIV disease progression among illicit drug users: a systematic review

OBJECTIVE

To systematically review factors associated with HIV disease progression among illicit drug users, focusing on exposures exogenous to individuals that likely shape access and adherence to HIV treatment.

DESIGN

A systematic review of peer-reviewed English-language studies among HIV-seropositive illicit drug users with at least one of these endpoint of interest: a diagnosis of AIDS; death; changes/differences in CD4 cell counts; or changes/differences in plasma HIV-1 RNA levels.

METHODS

Articles were included if they reported factors associated with an outcome of interest among a group of illicit drug users. Studies were identified, screened and selected using systematic methods.

RESULTS

Of 2668 studies matching the search criteria, 58 (2%) met the inclusion criteria, all but one from North America or western Europe. Overall, 41 (71%) studies contained significant individual-level clinical characteristics or behaviors (e.g. illicit drug use) associated with disease progression. Fifteen studies (26%) identified significant social, physical, economic or policy-level exposures, including incarceration, housing status or lack of legal income.

CONCLUSION

Although past studies demonstrate important environmental exposures that appear to shape access to care and subsequent disease progression, the limited literature to examine these factors demonstrates the need for future research to consider risk environment characteristics and the role they may play in shaping health outcomes from HIV infection among drug users through determining access and adherence to evidence-based care.

Relationship of injection drug use, antiretroviral therapy resistance, and genetic diversity in the HIV-1 pol gene

OBJECTIVES

To determine if a history of injection drug use influences genotypic protease inhibitor (PI) resistance to antiretroviral agents.

METHODS

We assessed the presence of resistance mutations in PI-naive injection drug users (IDUs) and non-IDUs participating in the Women's Interagency HIV Study. Eighteen HIV-infected participants who reported injection drug use before study enrollment and 32 HIV-infected non-IDUs contributed a total of 34 and 65 person-visits, respectively, to analyses.

RESULTS

Based on data from multiple clones obtained from different time points from each individual, we determined that primary PI resistance mutations were more frequent among person visits contributed by IDUs (24%) than non-IDUs (8%, P = 0.05). Although neither reached statistical significance, diversity was higher within the protease region among study visits carrying PI-resistant clones at both the nucleotide level (2.66 vs. 2.35; P = 0.08) and at the amino acid level (1.60 vs. 1.32; P = 0.23). Most of the primary resistance mutations could not be detected using the standard population sequencing employed in the clinical setting. Five of 6 individuals in whom clones encoding PI resistance mutations were identified failed PI-containing highly active antiretroviral therapy within 12 months of therapy initiation.

CONCLUSIONS

Our findings indicate that more aggressive sampling for resistance mutations among viral clones before highly active antiretroviral therapy initiation might permit selection of more effective treatment, particularly in IDUs.

Early immunologic and virologic responses to highly active antiretroviral therapy and subsequent disease progression among HIV-infected injection drug users

We examined the prevalence and prognostic value of early responses to highly active antiretroviral therapy (HAART) among community-based injection drug users (IDUs) in Baltimore. Virologic (HIV RNA <1000 copies/ml) and immunologic (CD4 >500 cells/ul or increase of 50 cells/ul from the pre-HAART level) responses were examined in the 1st year of HAART initiation. Cox regression was used to examine the effect of early response on progression to new AIDS diagnosis or AIDS-related death. Among 258 HAART initiators, 75(29%) had no response, 53(21%) had a virologic response only, 38(15%) had an immunologic response only and 92(36%) had a combined immunologic and virologic response in the first year of therapy. Poorer responses were observed in those who were older, had been recently incarcerated, reported injecting drugs, had not had a recent outpatient visit and had some treatment interruption within the 1st year of HAART. In multiple Cox regression analysis, the risk of progression was lower in those with combined virologic and immunologic response than in non-responders, (relative hazard [RH], 0.32; 95% confidence interval [CI], 0.17-0.60). Those with discordant responses had reduced risk of progression compared to non-responders but experienced faster progression than those with a combined response, although none of these differences was statistically significant. Early discordant and non response to HAART was common, often occurred in the setting of injection drug use and treatment interruption and was associated with poorer survival. Interventions to reduce treatment interruptions and to provide continuity of HIV care during incarceration among IDUs are needed to improve responses and subsequent survival.

Predictors of failure of first-line antiretroviral therapy in HIV-infected adults: Indian experience

OBJECTIVES

To study the incidence and risk factors for failure of treatment with antiretroviral therapy among adults in the national treatment program in India, and to estimate the possible number of persons living with human immunodeficiency virus (HIV) who will need a second-line treatment regimen in the next 3 and 3.5 years.

DESIGN AND SETTING

Data of a cohort of HIV-positive adult patients, who were enrolled in the government-sponsored antiretroviral therapy program, were obtained from the electronic medical record system of the largest HIV care center in India and subjected to analysis.

MAIN OUTCOMES

Treatment failure defined by the World Health Organization criteria, assessed immunologically on the basis of CD4 T cell count, with a minimum period of 12 months of follow-up and with a minimum of two CD4 T cell follow-up measures.

RESULTS

The cumulative incidence of treatment failure in the 1370 adult patients included in the study was 3.9% (95% confidence interval [CI] 2.9 to 4.9). Men had a 3.5 (1.6 to 7.4) times significantly greater risk of treatment failure. Patients who had negative changes in absolute lymphocyte count, hemoglobin concentration and body weight had 3.1 (1.6 to 6.2), 3.2 (1.6 to 6.2), and 3.5 (1.9 to 6.4) times significantly greater risk of treatment failure. In India, after 2007, by 2, 3, and 3.5 years, respectively, an estimated 16 000, 35 000, and 51 000 patients receiving antiretroviral therapy are likely to require second-line treatment.

CONCLUSION

Monitoring of hemoglobin concentration, absolute lymphocyte count, and body weight during follow-up emerged as inexpensive predictors of treatment failure in a resource-poor setting. A significant number of patients will need second-line therapy as a result of failure of their first-line antiretroviral therapy regimen in 3 and 3.5 years in India, and therefore the development of an appropriate policy for second-line drugs is urgently needed.

Inadequacies in antiretroviral therapy use among Aboriginal and other Canadian populations

We undertook this study to provide a profile of Aboriginal people initiating antiretroviral therapy and their response to treatment. Aboriginal peoples were identified through self-report. Baseline socio-demographics and risk factors were compared between Aboriginal and non-Aboriginal participants as were baseline factors associated with two consecutive plasma viral load measures below 500 copies/ml using contingency table analysis. Multivariate survival analysis of the prognostic factors associated with time to two consecutive plasma viral load measures below 500 copies/ml among eligible participants was undertaken to characterize response to antiretroviral therapy. There were 892 participants with available data for this analysis, of those 146 (16%) self-identified as Aboriginal. Aboriginal participants were more likely to be female (p < or = 0.001), have lower baseline plasma viral loads (p = 0.010), be co-infected with HCV (p < 0.001), live in unstable housing (p < or = 0.001), and report an income of >10K CDN (p < or = 0.001) per annum. Aboriginal people were less likely to report men who have sex with men (p < or = 0.001) and more likely to report injection drug use (p < or = 0.001) as a risk factor for HIV infection. Aboriginal participants were more likely to receive double versus triple combination antiretroviral therapy (p = 0.002), be less adherent in the first year on therapy (p = 0.001) and to have a physician less experienced with treating HIV (p < or = 0.001). When these factors were controlled for, Aboriginal people treated with triple combination therapy were as likely to respond and suppress their viral load below 500 copies. In the era of HAART, our results indicate that Aboriginal people living with HIV/AIDS were less likely to receive optimal therapy. However, when Aboriginals did receive triple drug therapy they suppressed just as well as non-Aboriginals.

Five year outcomes of a cohort of HIV-infected injection drug users in a primary care practice

Overall mortality related to HIV infection has declined with the advent of highly active anti-retroviral therapy (HAART). The purpose of this study was to examine the five-year outcomes of a cohort of 175 consecutive patients with HIV infection and injection drug use followed at a primary care practice. Patients were seen for their first visit between June 1994 and May 1998. At five years from their initial visit, 53 patients (30.3%) had died, while 47 (26.9%) were still active patients in our primary care practice. Of those who died, HIV was the cause of death in a little over half of patients (55%) followed by liver disease (15%) and drug overdose (11%). Only 80 patients ever received highly active anti-retroviral therapy (HAART) and 52 (65%) of these achieved an undetectable viral load. Patients who never received HAART had a five-year mortality of 34.8%, compared to 25.0% in patients who ever received HAART, p < .001. Our data underscore the high burden of morbidity and mortality associated with HIV infection among IDUs despite the availability of effective treatment.

Adherence to antiretroviral therapy: an empirical test of the information-motivation-behavioral skills model

Consistent and nearly perfect adherence is considered an essential requirement for HIV-positive patients on antiretroviral therapy (ART) to fully realize its life-extending benefits. The current study evaluated a comprehensive model of ART adherence--the information-motivation-behavioral skills (IMB) model. This model views adherence behavior as a function of the interrelations between adherence-related information, motivation, and behavioral skills. It hypothesizes that adherence-related information and motivation work through adherence-related behavioral skills to affect the initiation and maintenance of optimal ART adherence. In a series of structural equation models, the IMB model's critical constructs and assumptions were evaluated with a sample of 100 HIV-positive patients in clinical care. Across all analyses, the authors found support for the assumptions of the IMB model of ART adherence. Consistent with the model, adherence-related information and motivation related significantly to adherence-related behavioral skills, and behavioral skills related significantly to self-reported optimal adherence. Further, as predicted, the effects of information and motivation on self-reported adherence were mediated by adherence-related behavioral skills. Current study results are explored, and implications for adherence promotion interventions based on the model are discussed.

Club Drugs and HIV Infection: A Review

Club drug use is common among populations with human immunodeficiency virus (HIV) and populations at high risk for HIV infection. Club drugs have a myriad of acute and chronic medical consequences. Club drug-related visits to the emergency department and admissions for treatment of substance use have increased dramatically over the past 15 years. Most epidemiological data support the role of club drugs in increasing sexual risk behavior, with some studies demonstrating an independent association between use of certain club drugs and HIV infection. The direct influence of club drugs on progression of HIV disease remains to be determined; however, club drugs may interact with certain retroviral medications and have been associated with decreased adherence to medication. Clinicians should ask all patients about patterns of club drug use, counsel patients about the risks associated with club drug use, and refer patients to appropriate behavioral treatment programs for substance use when clinically indicated.

An empirical test of the information, motivation and behavioral skills model of antiretroviral therapy adherence

Nearly perfect adherence to demanding antiretroviral therapy (ART) is now recognized as essential for HIV-positive patients to realize its life sustaining benefits. Despite the dire consequences of non-adherence, a large number of patients do not follow their ART regimen. While many factors influence adherence, the literature is dominated by studies on only one or a small set of them. Multivariate, theory-based models of adherence behavior are of great interest. The current study tested one such model, the Information, Motivation and Behavioral Skills (IMB) model of ART adherence (Fisher et al., under review). A sample of HIV-positive patients on ART in clinical care in Puerto Rico (N=200) provided data on adherence-related information, motivation and behavioral skills as well as adherence behavior per se. Structural equation model tests used to assess the propositions of the IMB model of ART adherence provided support for the interrelations between the elements proposed by the model and extended previous work. Implications for future research and intervention development are discussed.

Do HIV Disease Progression and HAART Response Vary among Injecting Drug Users in Europe?

Prior to HAART availability, there was no evidence of a geographical variation in HIV disease progression among injecting drug users (IDU) from different European regions. Nowadays, factors of importance regarding HIV disease progression in the face of HAART availability, such as HAART access, adherence, and the organization of care for IDU may differ across Europe. Therefore we studied HIV disease progression in a European study of IDU with known dates of HIV-seroconversion. Results show that with ongoing HAART availability, the risk of HIV disease progression has continued to decrease. When accounting for pre-AIDS death (in AIDS analyses) and non-natural deaths (suicide, overdose, accidents and homicide, in analyses of death) which are common among IDU, the risk of AIDS and death has decreased by as much as 65% and 75%, respectively, in 2000/2001. Results show little geographic variation in progression to AIDS. All-cause mortality was higher in IDU from Glasgow than elsewhere, while in the Valencian region (Spain) IDU were at a significantly lower risk of non-natural deaths. The timing of HAART initiation by treatment-naïve IDU likewise differed across Europe: IDU in Amsterdam, Innsbruck, and Edinburgh started at significantly lower CD4 counts than IDU in Paris, Geneva, Glasgow, and the Valencian region, but the subsequent short-term immune response was similar. In conclusion, the risk in progression to AIDS or natural death is similar across western Europe although IDU across Europe differ in other factors, such as the risk of non-natural death and the timing of HAART initiation.

Simplified therapy with zidovudine, lamivudine, and abacavir for very nonadherent, treatment-failing patients

OBJECTIVE

To assess the effectiveness of a simplified therapy for very nonadherent patients who had previously failed with HAART.

METHOD

We performed a prospective open-label study of antiretroviral-experienced patients. Dosing schedule comprised (co-formulated) zidovudine, lamivudine, and abacavir bid. Eligible patients had to have plasma HIV RNA >5000 copies/mL, previous therapy, and very poor adherence to the medication regimen.

RESULTS

Eighty-five patients were included (mean viral load, 4.4 log/mL; mean CD4, 240 cells/mL; IDUs, 78%; methadone maintenance program, 42%; AIDS, 28%). Number of previous therapies: one, 53%; two, 28%; three or more, 19%. In the intent-to-treat analysis at 1 year, 38 patients (44.7%) achieved viral load below 500 copies/mL. Adherence greater than 90% of prescribed drugs was reported in 49% of patients, adverse events were reported in 17.6%, mortality in 6%, and lost to follow-up in 26%. The factors associated with virologic failure were nonadherence (odds ratio [OR], 4.4; 95% CI 1.5-12.3), baseline CD4 cell count <200 cells/mL (OR, 3.4; 95% CI 1.3-8.9; p =.01), and more than one previous treatment (OR, 2.7; 95% CI 1.1-6.9).

CONCLUSION

Regarding previously very nonadherent patients, this simplified combination therapy containing three NRTIs obtained satisfactory results in ART-experienced patients. However, more aggressive interventions to enhance adherence are needed to improve results.

Developing a directly administered antiretroviral therapy intervention for HIV-infected drug users: implications for program replication

Directly administered antiretroviral therapy (DAART) is one approach to improving adherence to among human immunodeficiency virus (HIV)-infected drug users. We evaluated the essential features of a community-based DAART intervention in a randomized, controlled trial of DAART versus self-administered therapy. Of the initial 72 subjects, 78% were racial minorities, and 32% were women. Social and medical comorbidities among subjects included homelessness (35% of subjects), lack of interpersonal support (86%), major depression (57%), and alcoholism (36%). At baseline, the median CD4+ cell count was 403 cells/mL and the median HIV-1 RNA load was 146,333 copies/mL (log10 5.31 copies/mL). During the prior 6 months, 33% of subjects had missed a medical appointment, and 47% had visited an emergency department. Although most subjects (67%) preferred to take their own medications, 76% would accept DAART if it were made compulsory. A methadone clinic was the DAART venue acceptable to the fewest subjects (36%), and a mobile syringe-exchange program was acceptable to the most subjects (83%). Adherence was higher for supervised than for unsupervised medication administration (P<.0001), a finding that supports use of daily supervision of once-daily regimens. Moreover, DAART should incorporate enhanced elements such as convenience, flexibility, confidentiality, cues and reminders, responsive pharmacy and medical services, and specialized training for staff.

Initiating Highly Active Antiretroviral Therapy and Continuity of HIV Care: The Impact of Incarceration and Prison Release on Adherence and HIV Treatment Outcomes

Objective

To examine the effect of incarceration within 12 months of initiating highly active antiretroviral therapy (HAART) on non-adherence and HIV-1 RNA suppression.

Methods

We compared the adherence and virological outcomes among participants in a population-based HIV/AIDS Drug Treatment Program in British Columbia, Canada, by history of incarceration in a provincial prison. Participants who were HIV-infected, naive to HAART and who were prescribed treatment between 1 July 1997 and 1 March 2002 were eligible for this study. Logistic regression was used to determine the factors associated with non-adherence and Cox proportional hazards modelling was used to determine the factors associated with HIV-1 RNA suppression adjusting for age, gender, history of drug use, baseline HIV-1 RNA, baseline CD4 cell count, type of antiretroviral regimen [two nucleosides + protease inhibitor (PI) vs two nucleosides + non-nucleoside reverse transcriptase inhibitor (NNRTI)], physician's HIV-related experience for each subject and adherence as measured by pharmacy refill compliance.

Results

There were 1746 subjects (101 incarcerated/ 1645 non-incarcerated) who started antiretroviral therapy between 1 July 1997 and 1 March 2002. Of those incarcerated, 50 initiated HAART while in prison and 27 subjects were released but returned to prison in the follow-up period. Subjects received antiretroviral therapy while incarcerated for a median number of 4 months [interquartile range (IQR): 2–10]. Multiple logistic regression results showed that a history of incarceration within 12 months of initiating HAART independently increased the odds of non-adherence [adjusted odds ratio (AOR): 2.40; 95% confidence interval (95% CI): 1.54–3.75]. A history of injected drug use was also associated with non-adherence (AOR: 1.49; 95% CI: 1.17–1.90). The following factors were negatively associated with non-adherence: older age (AOR: 0.81; 95% CI: 0.72–0.91), male sex (AOR: 0.50; 95% CI: 0.38–0.65) and higher physician HIV-related experience (AOR: 0.97; 95% CI: 0.96–0.98). In addition, a history of incarceration within 12 months of initiating HAART reduced the odds of achieving HIV-1 RNA suppression [adjusted hazards ratio (AHR): 0.68; 95% CI: 0.51–0.89]. Other factors negatively associated with viral suppression included a history of drug injection (AHR: 0.79; 95% CI: 0.69–0.91), two nucleosides + PI vs two nucleosides + NNRTI (AHR: 0.77; 95% CI: 0.69–0.87), higher baseline HIV-1 RNA (AHR: 0.66; 95% CI: 0.62–0.70). Higher adherence was positively associated with viral suppression (AHR: 1.38; 95% CI: 1.34–1.42). Among the 101 subjects who were incarcerated in the first year of starting HAART, the time spent in jail was positively associated with HIV-1 RNA suppression (HR: 1.06; 95% CI: 1.02–1.10).

Conclusion

HIV-infected subjects with a history of incarceration within 12 months of initiating HAART have higher odds of non-adherence and, consequently, lower probability of achieving HIV-1 RNA suppression. The longer their sentence, however, the higher the probability of virological suppression. The British Columbian provincial prison system provided a structured setting for HAART but subjects are unable to continue this level of adherence upon release. Strategies to ensure continuation of HIV/AIDS care for HIV-infected individuals leaving the criminal justice system must be a public health priority.

Differences in HIV disease progression by injecting drug use in HIV-infected persons in care

BACKGROUND

In the United States and many Western countries, injecting drug use continues to be an important cause of HIV infection. This has important clinical and public health implications if injecting drug users (IDUs) have greater barriers to antiretroviral effectiveness than other risk groups. We assessed if there were differences between HIV-infected IDUs and non-IDU patients in the development of AIDS-defining illnesses (ADIs) from the time the patients started their first combination antiretroviral therapy (CART) regimen.

METHODS

We compared clinical outcomes for IDU patients (n = 827) with those for non-IDU patients (n = 1314) after they started CART. We controlled for financial access, because all patients had access to CART through insurance or a drug assistance program. The incidence (number of ADI cases per 100 person-years) was compared for IDUs and non-IDUs from 1995 through 2002. Incidence ratios were calculated for IDUs compared with non-IDUs. Risk factors for development of ADIs were assessed using negative binomial regression.

RESULTS

From 1995-1996 to 2001-2002, there was a decline in ADI incidence among IDUs from 31.9 to 16.2 cases per 100 person-years of follow-up. Over the same time, there was a decline in ADI incidence among non-IDUs from 37.0 to 9.7 cases per 100 person-years. The incidence ratio (incidence among IDUs compared with that among non-IDUs) increased from 0.87 (95% confidence interval [CI], 0.65-1.15) to 1.67 (95% CI, 1.25-2.18) from 1995-1996 to 2001-2002. By negative binomial regression, the incidence ratio for ADIs among IDUs versus non-IDUs increased to 1.45 (95% CI, 1.21-1.75), after 1998, adjusting for differences in demographic, clinical, and treatment factors.

CONCLUSIONS

The relative incidence of ADIs among IDUs with access to treatment increased approximately 50% compared with non-IDUs since 1999. This suggests greater barriers to the effective use of CART for IDUs, resulting in a higher individual and public health burden of clinical HIV disease. It will be important to understand reasons for this growing difference and to implement appropriate interventions to improve the effective use of CART for IDUs.

Impaired virologic response to highly active antiretroviral therapy associated with ongoing injection drug use

Injection drug users who continue to use drugs may not respond to highly active antiretroviral therapy (HAART) as well as other HIV-infected individuals, even after adjusting for a reliable measure of adherence. We therefore compared the virologic response among participants in a population-based HIV/AIDS Drug Treatment Program in British Columbia, Canada, by injection drug use activity. Participants who were HIV infected and naive to antiretroviral therapy and who were prescribed antiretroviral treatment between August 1996 and December 2000 were eligible for this study. They were classified as current, former, or non-injection drug users. The main outcome was having two consecutive HIV-1 RNA levels less than 500 copies/mL. We used logistic regression to adjust for baseline HIV-1 RNA, type of antiretroviral regimen (2 nucleosides + nonnucleoside reverse transcriptase inhibitor versus 2 nucleosides + protease inhibitor), duration of therapy (months), adherence (derived from refill compliance data), and age. A total of 578 participants were first prescribed HAART during the study period. Among them, 78 (13%) were current injection drug users, 96 (17%) were former injection drug users, and 404 (70%) never injected drugs. In the multivariable logistic regression, relative to non-drug users, current injection drug users were significantly less likely to suppress their HIV-1 RNA (adjusted OR [AOR] = 0.30, 95% CI: 0.13-0.67), and former injection drug users were not significantly different from non-drug users (AOR = 0.56, 95% CI: 0.24-1.34). There was a significant interaction between drug use and adherence. In the analyses stratified by drug use, the adherence of former and non-drug users was positively associated with HIV-1 RNA suppression (AOR = 1.33, 95% CI: 1.14-1.55), whereas for current drug users, it was not (AOR = 1.07, 95% CI: 0.87-1.33). Current injection drug users were less likely to achieve HIV-1 RNA suppression compared with non-drug users. Adherence as measured by pharmacy refill compliance was not a reliable measure in this subpopulation.