A team of HIV researchers at UCSF recommend against establishing directly observed therapy (DOT) as the model for the provision of HIV medications in resource poor countries.
Writing in an editorial in the June 3, 2003 issue of AIDS, the researchers challenge the assumption that poverty is a risk factor for non-adherence to anti-HIV regimens and cite the issue of stigmatization.
“Without clear evidence that people in resource poor countries are less likely to adhere to HIV medication regimens than those in wealthy countries, it is difficult to argue for a delivery system that may compromise confidentiality and risk stigmatization,” said co-author, Cheryl Liechty, MD, clinical fellow in UCSF’s Division of Infectious Diseases.
The editorial references two recent South African studies that found treatment adherence among impoverished participants—in the absence of a formal adherence—ranged from 88 to 95 percent. This range compares to a 70 percent adherence rate measured in studies of HIV-infected individuals in wealthy countries.
“There is an assumption that all poverty acts the same. In this country, extreme poverty is often associated with issues of homelessness, mental illness and substance abuse. In resource poor countries, poverty is distributed relatively uniformly and is not linked to those issues that complicate adherence here,” said editorial’s co-author, David Bangsberg, MD, MPH, director of UCSF’s Epidemiology and Prevention Interventions Center at San Francisco General Hospital Medical Center.
Bangsberg’s center has pioneered the delivery of HIV medications to San Francisco’s HIV-positive homeless population.
The editorial notes that DOT for tuberculosis therapy became a public health imperative to prevent emergence of drug resistance strains of TB and that the possibility of creating drug resistant strains of HIV is cited as a rationale for DOT for HIV.
“Data regarding adherence and resistance do not support this view. Low rates of adherence are less likely to create drug resistant HIV than high rates of adherence by patients who are unable to completely suppress viral replication. If DOT increased adherence, it could actually function to move patients into a window where resistant virus is selected. While DOT might improve clinical outcomes if it improves adherence, the failure to prevent drug resistance lessens the public health imperative to attempt to ensure adherence ” said Bangsberg.
The possibility that DOT could reduce virus levels in infected individuals and thus make them less able to transmit HIV is also addressed by the editorial. The authors observe that there is no evidence yet that DOT is superior to self-administered therapy for reducing transmission through treatment, and if it were proved to be so, that the discussion of HIV DOT should not be limited to resource poor countries.
The work of the researchers is supported by The Doris Duke Charitable Foundation and the National Institute of Mental Health. The Epidemiology and Prevention Interventions Center is a component of UCSF’s AIDS Research Institute.