Nonadherence among HIV-infected injecting drug users: the impact of social instability

The authors tested the impact of social instability on adherence to highly active antiretroviral therapy (HAART) among patients infected with HIV through injection drug use (IDU; MANIF2000 cohort). In the study, they analyzed sociodemographic baseline characteristics to develop an indicator of social instability. Information concerning adherence to HAART was collected through questionnaires during a 2-year follow-up period. Factors associated with nonadherence were studied in two different groups: 1) patients who had stopped injection drug use (ex-IDUs) and who were not in drug maintenance programs (DMT) during the entire follow-up period, and 2) those who were still opiate dependent. Among the 210 eligible patients, 114 were classified as ex-IDUs and 96 as opiate dependent. Ex-IDUs reported nonadherence behaviors in 96 of 384 visits (25.0%), while opiate-dependent patients were nonadherent in 111 of 308 visits (36.0%; p = .02). Among ex-IDUs, the only factor associated with nonadherence was social instability, while among opiate-dependent patients, injection behavior was the only determinant of nonadherence behavior. For opiate-dependent patients, DMT may enhance adherence to HAART, but only if it is successful in reducing abuse of injection practices. For ex-IDUs, it is very important that the management of social difficulties be taken into account to increase adherence to HAART.     

Relationship between HAART adherence and adipose tissue alterations

Adipose tissue alterations (ATA), which are common among persons treated with highly active antiretroviral therapy (HAART), can have substantial psychologic repercussions, with a subsequent negative impact on the patient's quality of life and on HAART adherence. However, the cross-sectional nature of the studies precludes establishing the direction and causality of the relationship. The authors evaluated the longitudinal relationship between ATA and adherence to HAART. The analysis included all participants in the AdICoNA and the LipolCoNA substudies of the Italian Cohort Naive Antiretrovirals (ICoNA). Adherence was assessed using a 16-item self-administered questionnaire, which also included a question on self-perceived fat accumulation experienced during the past 4 weeks. ATA was diagnosed by physicians at enrollment and evaluated every 6 months thereafter. There were 207 patients, with a median age of 35 years; 73% were men; and 34% acquired HIV through injection drug use. At baseline, nonadherence was reported by 63% of participants, and ATA was self-perceived by 15% and clinically diagnosed in 25%. Using Cox regression analysis, patients with good adherence at baseline were more likely to develop ATA (RH = 2.58; 95% CI, 1.09-6.11) and developed it sooner. Self-perceived ATA at baseline was independently related to subsequent nonadherence (OR, 4.67; 95% CI, 1.01-22.4), but clinically diagnosed ATA was not (OR, 0.77; 95% CI, 0.37-1.61). Patients' adherence to HAART is a dynamic process that interacts with ATA. Better adherence is associated with a higher risk of subsequent occurrence of ATA, while patient-perceived onset of morphologic alterations can reduce adherence to antiretroviral therapy.     

Predictors of self-reported antidepressant adherence

The authors' objectives of this research were: (1) to assess levels of selfreported antidepressant adherence and reasons for nonadherence and (2) to investigate determinants of nonadherence. A group of general hospital and community psychiatry practice mood disorder outpatients (n=80) took a self-report questionnaire that assessed beliefs about antidepressants, self-efficacy, and reasons for nonadherence. High levels of adherence were reported: 58 patients (73%) indicated they took their medication as directed more than 80% of the time. Practical issues (e.g., simply forgetting or a change in routine) were the most frequently identified reasons for nonadherence. Patients were more likely to report nonadherence if they experienced a sexual side effect, had lower self-efficacy, were female, and had not completed post-secondary education. Clinicians should be cognizant of this complexity and address not only issues related to medication efficacy and tolerability, but also social mediators and health beliefs when prescribing antidepressants.     

Detrimental effects of continued illicit drug use on the treatment of HIV-1 infection.

OBJECTIVE: To identify the effects of substance abuse status (active, former, and never) on utilization of highly active antiretroviral therapy (HAART), medication adherence, and virologic and immunologic responses to therapy. DESIGN: Prospective cohort study of 764 HIV-1-infected patients who attended an urban HIV clinic and participated in a standardized interview. MAIN OUTCOME MEASURES: Past utilization of HAART, self-reported nonadherence with antiretroviral therapy, and changes in HIV-1 RNA level and CD4+ lymphocyte count relative to prior peak and nadir, respectively. RESULTS: Forty-four percent of active drug users failed to utilize HAART compared with 22% of former drug users and 18% of non-drug users (p <.001 for both comparisons). Among participants who were taking antiretroviral therapy when interviewed, active drug users were more likely to report medication nonadherence (34% vs. 24% of nonusers and 17% of former users), had a smaller median reduction in HIV-1 RNA from baseline (0.8 log10 copies/ml vs. 1.7 in nonusers and 1.6 in former users), and had smaller median increases in CD4+ lymphocyte count from baseline (65 cells/mm3 vs. 116 in nonusers and 122 in former users) (p <.05 for all comparisons with active users). CONCLUSIONS: Active drug use was strongly associated with underutilization of HAART, nonadherence, and inferior virologic and immunologic responses to therapy, whereas former drug users and non-drug users were similar in all outcomes. Effective strategies are needed that integrate HIV-1 and substance abuse treatments.     

Correlates and predictors of adherence to highly active antiretroviral therapy: overview of published literature

Knowledge of factors associated with medication adherence could help HIV clinicians to target persons in need of intervention, design these interventions, and help researchers to plan studies of adherence. This review summarizes the results of 20 studies investigating the issue of barriers to optimal highly active antiretroviral therapy (HAART) adherence. Only a few determinants were consistently associated with nonadherence. Symptoms and adverse drug effects, psychologic distress, lack of social or family support, complexity of the HAART regimen, low patient self-efficacy, and inconvenience of treatment were the factors most consistently associated with nonadherence. There were inconsistent findings regarding the relationship of adherence and the following variables: sociodemographic characteristics, substance abuse, depressive symptoms, quality of life, CD4+ cell count, knowledge and beliefs about treatment, patients' satisfaction with health care, and patient-provider relationship. A synthesis of findings relating various factors to adherence to HAART is difficult to reach because of several limitations of the existing body of research. These limitations concern the measurement of adherence, the assessment of correlates and predictors of adherence, the study population, and the study design.     

Microsocial environmental influences on highly active antiretroviral therapy outcomes among active injection drug users: the role of informal caregiving and household factors

Active injection drug users (IDUs) are at high risk of unsuccessful highly active antiretroviral therapy (HAART). We sought to identify baseline factors differentiating IDUs' treatment success versus treatment failure over time among those taking HAART. Interventions for Seropositive Injectors-Research and Evaluation (INSPIRE) study participants were assessed at baseline and at 6- and 12-month follow-ups. Multinominal regression determined baseline predictors of achieving or maintaining viral suppression relative to maintaining detectable viral loads over 12 months. Of 199 participants who were retained and remained on HAART, 133 (67%) had viral load change patterns included in the analysis. At follow-up, 66% maintained detectable viral loads and 15% achieved and 19% maintained viral suppression. Results indicated that those having informal care (instrumental or emotional support) were 4.6 times more likely to achieve or maintain viral suppression relative to experiencing treatment failure. Those who maintained viral suppression were 3.5 times less likely to live alone or to report social discomfort in taking HAART. Study results underscore the importance of microsocial factors of social network support, social isolation, and social stigma for successful HAART outcomes among IDUs. The findings suggest that adherence interventions for IDUs should promote existing informal HIV caregiving, living with supportive others, and positive medication-taking norms among social networks.     

Prevalence and predictors of highly active antiretroviral therapy use in patients with HIV infection in the united states. HCSUS Consortium. HIV Cost and Services Utilization

BACKGROUND: Highly active antiretroviral therapy (HAART) became standard for HIV in 1996. Studies at that time showed that most people infected with HIV had initiated HAART, but that members of minority groups and poor people had lower HAART use. It is not known whether high levels of HAART use have been sustained or whether socioeconomic and racial disparities have diminished over time. OBJECTIVES: To determine the proportion of patients who had received and were receiving HAART by January 1998, and to evaluate predictors of HAART receipt. DESIGN AND PARTICIPANTS: Prospective cohort study of a national probability sample of 2267 adults receiving HIV care who completed baseline, first follow-up, and second follow-up interviews from January 1996 to January 1998. MAIN OUTCOME VARIABLES: Proportion currently using HAART at second follow-up (August 1997 to January 1998), contrasted with the cumulative proportions using HAART at any time before January 1998 and before December 1996. ANALYSES: Bivariate and multiple logistic regression analysis of population characteristics predicting current use of HAART at the time of the second follow-up interview. RESULTS: The proportion of patients ever having received HAART increased from 37% in December 1996 to 71% by January 1998, but only 53% of people were receiving HAART at the time of the second follow-up interview. Differences between sociodemographic groups in ever using HAART narrowed after 1996. In bivariate analysis, several groups remained significantly less likely to be using HAART at the time of the second follow-up interview: blacks, male and female drug users, female heterosexuals, people with less education, those uninsured and insured by Medicaid, those in the Northeast, and those with CD4 counts of >/=500 cells/microl (all p <.05). Using multiple logistic regression analysis, low CD4 count (for CD4 <50 cells/microl: odds ratio [OR], 3.20; p <.001) remained a significant predictor of current HAART use at the time of the second follow-up interview, but lack of insurance (OR, 0.71; p <.05) predicted not receiving HAART. CONCLUSIONS: The proportion of persons under HIV care in the United States who had ever received HAART increased to over 70% of the affected population by January 1998 and the disparities in use between groups narrowed but did not disappear. However, nearly half of those eligible for HAART according to the U.S. Department of Health and Human Services guidelines were not actually receiving it nearly 2 years after these medications were first introduced. Strategies to promote the initiation and continuation of HAART are needed for those without contraindications and those who can tolerate it.     

Viral Suppression and Antiretroviral Medication Adherence Among Alcohol Using HIV-Positive Adults

Background

Substance use is a known predictor of poor adherence to antiretroviral therapies (ART) in people living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome. Less studied is the association between substance use and treatment outcomes, namely, suppression of HIV replication.

Methods

Adults living with HIV (N?=?183) who reported alcohol use in the previous week and receiving ART were observed over a 12-month period. Participants completed computer interviews, monthly unannounced pill counts to monitor ART adherence, and daily cell-phone delivered interactive-text assessments for alcohol use. HIV viral load was collected at baseline and 12-month follow-up from medical records. Analyses compared participants who had undetectable HIV viral loads at baseline and follow-up (sustained viral suppression) to those with unsustained viral suppression. Analyses also compared participants who were adherent to their medications (>85 % pills taken) over the year of observation to those who were nonadherent.

Results

Fifty-two percent of participants had unsustained viral suppression; 47 % were ART nonadherent. Overall results failed to demonstrate alcohol use as a correlate of sustained viral suppression or treatment adherence. However, alcohol use was associated with nonadherence among participants who did not have sustained viral suppression; nonadherence in unsustained viral suppression patients was related to drinking on fewer days of assessment, missing medications when drinking, and drinking socially.

Conclusions

Poor HIV treatment outcomes and nonadherence were prevalent among adults treated for HIV infection who drink alcohol. Drinking in relation to missed medications and drinking in social settings are targets for interventions among alcohol drinkers at greatest risk for poor treatment outcomes.     

The impact of adherence on CD4 cell count responses among HIV-infected patients

BACKGROUND: There have been concerns that irreversible immune damage may result if highly active antiretroviral therapy (HAART) is initiated after the CD4 cell count declines to below 350 cells/microL; however, the role of antiretroviral adherence on CD4 cell count responses has not been well evaluated. METHODS: We evaluated CD4 cell count responses of 1522 antiretroviral-naive patients initiating HAART who were stratified by baseline CD4 cell count (<50, 50-199, and >or=200 cells/microL) and adherence. RESULTS: Among patients starting HAART with <50 cells/microL, during the fifth 15-week period after the initiation of HAART, absolute CD4 cell counts were 200 cells/microL (interquartile range [IQR]: 130-290) for adherent patients versus 60 cells/microL (IQR: 10-130) for nonadherent patients. Similarly, among patients starting HAART with 50 to 199 cells/microL, during the fifth 15-week period after the initiation of HAART, absolute CD4 cell counts were 300 cells/microL (IQR: 180-390) versus 125 cells/microL (IQR: 40-210) for nonadherent patients. In Cox regression analyses, adherence was the strongest independent predictor of the time to a gain of >or=50 cells/microL from baseline (relative hazard [RH] = 2.88, 95% confidence interval [CI]: 2.46-3.37). Among patients with baseline CD4 cell counts <200 cells/microL, adherence was the strongest independent predictor of the time to a CD4 cell count >200 cells/microL (RH = 4.85, 95% CI: 3.15-7.47). CONCLUSIONS: These data demonstrate that substantial CD4 gains are possible among highly advanced adherent patients and should contribute to the ongoing debate over the optimal time to initiate HAART.     

Applying the theory of planned behavior to explore HAART adherence among HIV-positive immigrant Latinos: elicitation interview results

Objective

This study explored influences on intention to adhere to highly active antiretroviral therapy (HAART) among immigrant Latinos living with HIV/AIDS in the southeastern USA.

Methods

Our community-based participatory research (CBPR) partnership completed individual in-depth interviews with 25 immigrant Latinos, based on the theory of planned behavior (TPB), to explore beliefs toward HAART adherence and HIV testing.

Results

Participants identified (a) seven outcomes of treatment adherence (e.g., “feeling good” and “controlling the virus”), (b) six groups of persons influencing adherence (e.g., family, partner/spouse), and (c) nine impediments to adherence (e.g., appointment scheduling, side effects of treatment). Fear of deportation, perceived costs of services, and barriers to communication emerged as impediments to both HAART adherence and HIV testing.

Conclusion

The findings suggest the utility of TPB in identifying factors to enhance HAART adherence among immigrant Latinos. Future research should explore the extent to which these identified TPB components quantitatively influence adherence intention and immunological and virological outcomes.

Practice implications

Culturally congruent interventions for immigrant Latinos may need to focus on facilitators of adherence, influential referent groups, and destigmatizing HIV/AIDS.     

Self-Reported Nonadherence with Antiretroviral Drugs Predicts Persistent Condition

Abstract

Purpose: To assess variables predictive of nonadherence persisting over time in HIV-infected people treated with highly active antiretroviral therapy. Method: Prospective study of consecutive HIV-infected patients who were prescribed ritonavir- or indinavir-containing regimens in a university-based HIV clinic in Rome. A patient questionnaire assessing knowledge of treatment regimen, adherence behavior, reasons for taking and missing therapy, factors influencing adherence, and health behaviors was administered at baseline and 1 year later. A predose protease inhibitor plasma level was measured concurrently. Persistent nonadherence was defined as patient self-reported nonadherence both at enrollment and at follow-up questionnaires. Results: From April 1998 to July 1998, 140 patients were enrolled into the study. At follow-up, 10% remained persistently nonadherent, and 15% of the previously adherent patients became nonadherent. On bivariate analysis, being less than 35 years old (odds ratio [OR] 8.9; 95% CI 1.8-43.1; p = .002), self-reporting nonadherence at enrollment (OR 14.5; 95% CI 3.5-5.8; p < .001), and having experienced ‘a fair amount’ or ‘a lot’ of vomiting (OR 11.1;95% CI 1.6-74.7; p = .02) or pruritus (OR 16.4; 95% CI 2.6-102.8; p = .004) during the 4 weeks before enrollment were significantly correlated to persistent nonadherence. Conclusion: Previous self-reported nonadherence was a strong predictor of persistent nonadherence during follow-up. Moreover, being of younger age and self-reporting vomiting or pruritus were also associated with a higher risk of nonadherence persisting over time.     

Treatment-related factors and highly active antiretroviral therapy adherence

Adherence to highly active antiretroviral therapy (HAART) plays a critical role in the effectiveness of HIV treatment. Nevertheless, the complexity of regimens and frequent side effects make HAART extraordinarily difficult to take, and many HIV-infected persons fail to adhere. The current study offers an overview of the relationship between adherence and antiretroviral treatment-related variables. As for other chronic diseases, medication regimen complexity also has an impact on adherence in the management of HIV infection. In particular, the authors discuss the effect of pill burden, dosing frequency, dietary instructions, number and type of different medications prescribed, short- and long-term side effects, convenience, and ability to incorporate the treatment regimen into a daily routine. Medication side effects are common in HAART-treated persons and are associated with concurrent and future nonadherence. Simplification of regimens, adjustment of the drug schedule to the patient's specific lifestyle, and anticipation and self-management of side effects are treatment-based strategies to optimize HAART adherence and ensure the most effective, convenient, safe, and well-tolerated antiretroviral treatment.     

Patients' perceptions of highly active antiretroviral therapy in relation to treatment uptake and adherence: the utility of the necessity-concerns framework

OBJECTIVE: To test the utility of the necessity-concerns framework in predicting highly active antiretroviral therapy (HAART) uptake and adherence. METHODS: This was a prospective follow-up study. Consecutive patients who were not currently receiving HAART were referred by their HIV physician. Immediately after a recommendation of HAART, patients completed the Beliefs about Medicines Questionnaire assessing their perceptions of personal necessity for HAART and concerns about potential adverse effects. The influence of these beliefs on the decision to accept or decline HAART and adherence 12 months later were assessed. RESULTS: One hundred fifty-three participants were given a recommendation of HAART, and 136 (88.9%) returned completed questionnaires. Thirty-eight participants (28%) initially rejected the treatment offer. Uptake of HAART was associated with perceptions of personal necessity for treatment (odds ratio [OR]=7.41, 95% confidence interval [CI]: 2.84 to 19.37) and concerns about potential adverse effects (OR=0.19, 95% CI: 0.07 to 0.48). There was a significant decline in adherence over time. Perceived necessity (OR=2.19, 95% CI: 1.02 to 4.71) and concerns about adverse effects (OR=0.45, 95% CI: 0.22 to 0.96), elicited before initiating HAART, predicted subsequent adherence. These associations were independent of clinical variables and depression. CONCLUSIONS: The necessity-concerns framework is a useful theoretic model for understanding patient perspectives of HAART and predicting uptake and adherence, with implications for the design of evidence-based interventions.     

Treatment adherence and illness self-management: introduction to the special issue

The current issue is devoted broadly to research on treatment adherence and chronic illness self-management behavior. As the prevalence of chronic illness increases, the pervasive problem of treatment nonadherence is increasingly viewed as having a major impact on treatment outcomes, public health and healthcare costs, making this issue particularly timely. Sixteen articles spanning an array of topics are presented; articles include empirical studies, statistical simulations, systematic reviews, and theoretical commentaries. Studies conducted with diverse patient populations (e.g., chronic headache, diabetes, end-stage renal disease, HIV, hypertension, severe obesity), samples (e.g., adolescents, ethnic/racial minorities, low-income adults, parents, spousal dyads), and designs (e.g., cross-sectional, longitudinal assessment, randomized controlled trial), are represented. This issue highlights psychosocial factors associated with nonadherence, promising interventions to promote adherence, and state-of-the art methods for the study of illness self-management. We hope these articles engender even more high quality, methodologically rigorous research in this important subfield of behavioral medicine.     

Anemia in HIV-infected patients receiving highly active antiretroviral therapy.

BACKGROUND: Anemia is common in HIV infection, particularly in advanced disease states. We wished to determine how highly active antiretroviral therapy (HAART) and other factors affected the level of hemoglobin in HIV infection. METHODS: We analyzed data from 905 patients receiving care at Johns Hopkins in Baltimore, Maryland after July 1, 1996. Analyses were done of hemoglobin levels obtained at baseline and during 1 year of follow-up in patients who received and did not receive a HAART regimen. Use of HAART and other demographic and clinical factors were examined. RESULTS: Eleven percent of patients had a hemoglobin count <10 g/dL, 27% had a hemoglobin count 10 to 12 g/dL, and 21% had a hemoglobin count of >14 g/dL at baseline before HAART was started. During 1 year of follow-up, use of HAART was associated with a hemoglobin levels >14 g/dL in 42% of patients, irrespective of use of zidovudine as part of HAART regimen, compared with 31% of patients who did not use HAART. In multivariate analysis, use of HAART was strongly associated with not having anemia during 1 year of follow-up, adjusting for patient gender, race, injection drug use history, baseline CD4 and HIV-1 RNA levels, and anemia treatments. CONCLUSIONS: HAART is an effective treatment of the anemia of HIV infection. Patients who continue to have symptomatic anemia while receiving HAART may need additional intervention.     

Treatment adherence improves outcomes and manages costs

Our experience with other chronic diseases, such as hypertension, diabetes, and asthma, has shown that adherence to treatment over time is about 50%. In HIV treatment, a significantly higher rate of adherence (i.e., 95% or greater) is required to achieve good outcomes. HAART is effective and cost-effective. Even with the high cost of antiretroviral drugs, the decrease in hospital utilization in addition to improved quality of life with HAART more than offsets the increased cost of drugs. This cost shifting from hospital utilization has been shown to result in a decrease of total monthly costs of care in many settings. In addition to decreased mortality and cost savings from decreased hospital utilization associated with HAART, the appropriate use of expensive antiretroviral drugs and the resultant reduction in antiretroviral resistance can save lives and money over the long term. However, we know that the performance of drugs in clinical trials is not always borne out in today's real world of ambulatory HIV care, underscoring the need for treatment adherence strategies in the HAART era. Our understanding of what improves adherence to antiretroviral treatment is still incomplete. However, there are a number of approaches that address the patient, the provider/multidisciplinary team, and the treatment regimen itself. The dedicated TAC, while not the only solution, has been shown to be an effective team member and a solution worth considering in managed care settings. When added to the costs of today's care, this team member should still prove cost-effective in the final analysis.     

The dynamic of adherence to highly active antiretroviral therapy: results from the French National APROCO cohort.

OBJECTIVES: Our objective was to describe the evolution of adherence to highly active antiretroviral therapy (HAART) over a 20-month period and its relationship with virologic success. METHODS: Self-reported adherence, clinical, and virologic data were collected 4 (M4), 12 (M12), and 20 (M20) months after initiation of a protease inhibitor-containing regimen in the French APROCO cohort. At each visit, patients were classified as nonadherent, moderately, or highly adherent, and HIV plasma RNA was determined. RESULTS: Among the 762 patients who were regularly followed until M20, the 436 patients who answered to all questionnaires, including adherence measurement, were selected for the analysis. The proportion of highly adherent patients was 55.7%, 62.2%, and 60.3% at M4, M12, and M20, respectively. A total of 137 patients (31.4%) was "always," 225 (51.6%) "sometimes," and 74 (17.0%) "never" "highly adherent" during follow-up. After multiple adjustment for known baseline predictors, virologic success after 20 months of HAART was more likely achieved in patients who were always (odds ratio [OR] 95% confidence interval [CI], 3.02 [1.64-5.58]) or sometimes (OR [95% CI], 2.15 [1.24-3.74]) "highly adherent." CONCLUSION: Adherence behavior is a dynamic process. Continued adherence was associated with better response to therapy and should be encouraged to reduce the risk of virologic failure.     

Depressive symptoms, neurocognitive impairment, and adherence to highly active antiretroviral therapy among HIV-infected persons

The association of depressive symptoms, neurocognitive impairment, and adherence to highly active antiretroviral therapy (HAART) was evaluated in 135 HIV-infected persons. Thirty percent reported nonadherence to HAART. Depressive symptoms (assessed with the Montgomery-Asberg Depression Rating Scale) and neurocognitive impairment (assessed with a neuropsychological test battery) were documented in 24% and 12%, respectively, of the study participants. Nonadherence to HAART was independently associated with worse depression rating scale scores (odds ratio=1.05, 95% confidence interval [CI]=1.00-1.10), acquisition of HIV through injection of drugs (odds ratio=2.59, 95% CI=1.05-6.39), and complaints about impairment of sexual activity (odds ratio=6.62, 95% CI=1.16-37.6). The presence of depressive symptoms, but not neurocognitive impairment, was associated with nonadherence.     

Marijuana use and its association with adherence to antiretroviral therapy among HIV-infected persons with moderate to severe nausea

BACKGROUND: Adherence to antiretroviral therapy (ART) is essential to successful treatment of HIV infection. Two recent studies reported a negative correlation between marijuana use and adherence to ART. Some patients, however, report that smoking marijuana improves adherence to ART. This study therefore sought to identify which subgroups of patients may have differential adherence to ART in association with recent marijuana use. METHODS: Cross-sectional survey design within a public health care system for HIV/AIDS. RESULTS: With a 5% refusal rate, 252 patients completed the interview, 175 (69%) were on ART, and 168 (67%) provided ART adherence data. Forty-one subjects (24%), predominantly whites, used marijuana. In bivariate analysis, no association between ART adherence and marijuana use was found (odds ratio [OR] = 0.92, 95% CI = 0.4-1.9). Adherence was positively associated with undetectable plasma virus and negatively associated with alcohol and other illicit drug use. Examining subgroups of patients, among those with nausea, marijuana users were more likely to show an association with adherence than nonusers (OR = 3.3), while among those without nausea, marijuana use was lower associated with adherence (OR = 0.52, P for homogeneity 0.02). This relationship was confirmed in multivariate analyses controlling for the interactions between nausea and marijuana use, in which other illicit drug use remained a factor related to nonadherence. DISCUSSION: These data suggest that medicinal use of marijuana may facilitate, rather than impede, ART adherence for patients with nausea, in contrast to the use of other illicit substances, which were associated with lower rates of ART adherence. To demonstrate any causal relationship between marijuana and adherence would require a longitudinal or controlled study.