Adherence to highly active antiretroviral therapy in the homeless population in San Francisco: a prospective study

Health care for the homeless assesses the use of adapted clinical practice guidelines

This article describes a process of evaluating and adapting existing clinical practice guidelines (CPGs) for homeless individuals by different healthcare providers in multiple healthcare settings across the country. Data were collected using a standardized evaluation tool in nine sites across the United States. Clinicians completed an evaluation of the CPG after every use. Most clinicians used the CPG five times. Descriptive statistics were reported on the characteristics of the clinicians, and the utility of the guidelines and written comments. Clinicians had an average of 12 years of clinical experience, 8 years of which were specifically spent working with homeless individuals. Ninety-one percent of the clinicians practiced in urban settings. The majority of clinicians felt the adapted guidelines met evaluation criteria. The major weaknesses reported the delineation of outreach and case management activities. Results did not vary by clinicians' disciplines, years of experience, or any other indicators. Clients and clinicians providing primary care to homeless individuals may benefit from utilizing Health Care for the Homeless Clinicians' Network adapted CPGs to assure quality, evidenced-based care to a vulnerable population.

Adherence-resistance relationships for protease and non-nucleoside reverse transcriptase inhibitors explained by virological fitness

OBJECTIVE

To compare the prevalence of resistance by adherence level in patients treated with non-nucleoside reverse transcriptase inhibitors (NNRTI) or protease inhibitors (PI). Also to examine the mechanism of differential class-specific adherence-resistance relationships, focusing on the patient-derived capacity of wild-type and drug-resistant recombinant variants to replicate in vitro in the presence of variable drug levels.

METHODS

Participants received unannounced pill count measures to assess adherence, viral load monitoring, and genotypic resistance testing. The replicative capacity of drug-susceptible and drug-resistant recombinants was determined using a single-cycle recombinant phenotypic susceptibility assay. Drug exposure was estimated using population-averaged pharmacological measurements adjusted by participant-specific levels of adherence.

RESULTS

In the NNRTI-treated group, 69% had resistance at 0-48% adherence compared to 13% at 95-100% (P = 0.01). PI resistance was less common than NNRTI resistance at 0-48% adherence (69% versus 23%; P = 0.01). In multivariate analysis, the odds for PI resistance increased (P = 0.03) while the odds for NNRTI resistance decreased (P = 0.04) with improving adherence. Individuals with drug-resistant variants were more likely to have levels of drug exposure where the resistant variant was more fit than the drug-susceptible variant in vitro, while those with drug-susceptible virus were more likely to have levels of drug exposure where the drug-susceptible virus was more fit than the drug-resistant variant (P = 0.005).

CONCLUSIONS

NNRTI resistance was more common than PI resistance at low levels of adherence. Class-specific adherence-resistance relationships are associated with the relative replicative capacity of drug-resistant versus wild-type variants to replicate in the presence of clinically relevant drug levels.

Long-term adherence to first-line highly active antiretroviral therapy in a hospital-based cohort: predictors and impact on virologic response and relapse

A high level of adherence to highly active antiretroviral therapy (HAART) is essential to minimize the risk of treatment failure and HIV disease progression. This cohort study evaluated the prevalence and predictors of long-term adherence with first-line HAART in a hospital-based unselected sample of HIV patients from central Italy, and examined the association between adherence and virological response or relapse. Between July 1996 and June 2004, 171 patients (67.3% males; mean age, 41.2 years) were followed for at least 24 weeks and up to 8 years. Adherence was measured by patient self-reports and confirmed using pharmacy records. The prevalence of high-level adherence (>or=90%) at 6 months was 88.3%; slightly less than 80% at 12 months. The incidence of adherence failure in the sample remained fairly stable until 24 months of follow-up, then it declined about 5% every 6 months. Cox analysis showed that compared to single/separated patients, homeless and married persons were, respectively, 1.95 times more likely and two times less likely to experience adherence failure (p < 0.05). The adjusted risk of adherence failure among patients who did not suffer drug-related toxicity was 0.57 (p < 0.05). Medication adherence was significantly associated with shorter time to virological response and longer time to relapse. Adherents were 1.69 times more likely to achieve viral suppression and nine times less likely to experience relapse than nonadherents (p < 0.01). Efforts at improving adherence should be prolonged for at least 24 months. A protective role of marriage for adherence failure is promising but requires confirmation in further research, that should also clarify the exact mechanisms determining the association.

Homelessness and psychological distress as contributors to antiretroviral nonadherence in HIV-positive injecting drug users

High levels of adherence to antiretroviral medications are required to maximize therapeutic benefits and viral suppression. Injecting drug use (IDU) is associated with decreased adherence levels, unstable living conditions and mental health problems. Despite the prevalence of these nonadherence risks in HIV-positive IDUs, little study has been conducted to date to assess the impact of homelessness and psychological distress on adherence in this population. The present study evaluated the effects of housing status (homeless/marginally housed versus nonhomeless) and psychological distress, measured via depression, anxiety and perceived stress, on self-reported adherence in 58 HIV-positive IDUs. Results from this study indicated that homeless/marginally housed HIV-positive IDUs reported higher levels of anxiety and perceived stress than their nonhomeless counterparts. The groups reported similar levels of depression. However, only depression was significantly related to adherence. Housing status, drug or alcohol use, and other demographic variables including gender, race/ethnicity, and years of education, were not associated with adherence. This study also found a relatively high rate of adherence in homeless/marginally housed IDUs with more than half (63%) reporting perfect (100%) adherence levels. Findings from this study suggest that when evaluating patient readiness for antiretroviral medications, current housing may not need to be the primary concern. Rather, depression may be a more potent indicator of nonadherence than homelessness for HIV-positive IDUs.