Directly observed therapy shown to be of value for some patients

A modified form of directly observed therapy (often abbreviated as DOTS) can increase the effectiveness of antiretroviral therapy amongst a subset of HIV-positive patients with drug abuse or social problems, according to a US study published in the August 15^th edition of AIDS. However, the investigators from Providence, Rhode Island, found that the majority of individuals enrolled on the directly observed therapy programme dropped out before completing six months of observation.

Many HIV-positive individuals have not fully benefited from antiretroviral therapy, either because of difficulties in accessing HIV care, or an inability to adhere to treatment regimens. Many of these patients are active drug users, have mental health problems, or are homeless. Adherence to tuberculosis therapy has been successfully improved in many settings by the use of directly observed therapy.

Investigators from Rhode Island examined the value of a modified form of directly observed therapy amongst 69 HIV-positive patients, the majority of whom had an active substance misuse problem. The study was intended to last twelve months, with the investigators reporting on six months data.

The patients were referred to the researchers by their doctors either because they had a persistently detectable HIV viral load despite repeated attempts to improve adherence or because they were currently using illicit drugs.

Individuals were prescribed a once-daily antiretroviral treatment regimen whenever possible. Medication was delivered five – seven days per week by a “near peer” outreach worker for the first three months of the study and one to three times a week thereafter. Patients were asked to keep a record of the doses they took which were not observed by the outreach worker. At three and six months they completed a questionnaire detailing their satisfaction with the directly observed therapy.

In addition, the investigators collected data on changes in viral load and CD4 cell count amongst patients enrolled in the study. They also compared changes in viral load and CD4 cell count between those patients who completed three and six months of follow-up and the majority of patients who did not.

Enrolment started in 2000, with a total of 69 individuals recruited to the study. The median age of participants was 43 years, 41% were white, 27% black and 22% Hispanic, 80% reported current drug use, 71% had a history of imprisonment and 9% were currently employed.

After just one month, only 56 patients were still participating in the study. This fell to 44 patients after three months and fell further to only 31 patients after six months. Imprisonment, treatment holidays and hospitalisation were amongst the reasons why people withdrew from the study.

At baseline, median CD4 cell count was 139 cells/mm³ and median viral load was 63,000 copies/ml. Of the patients who remained in the study, the median reduction in viral load was 1.56 log₁₀ after one month of directly observed therapy, 2.34 log₁₀ after three months and 2.7 log₁₀ after six months. After six months, the median increase in CD4 cell count amongst those patients who had continued to receive directly observed therapy was 64 cells/mm³.

Substance abuse was reported by approximately a third of patients who continued with the study at all time points. The investigators note that 83% of patients who used illicit drugs and received directly observed therapy achieved a viral load below 500 copies/ml.

Of the patients who remained on the study, 100% after three months, and 90% after six months said that the directly observed therapy had helped them to take their medication. In addition, the directly observed therapy was not regarded as an invasion of privacy by 81% of patients at month three and 94% at month six.

The therapy also appeared to improve the confidence of patients. At month three only 58% of those still on the study said that they would be confident taking their medication without the support of their outreach worker. This increased to 81% by month six.

The investigators compared viral load between patients who remained on the study and those who withdrew. They found that the median fall in viral load amongst patients who received directly observed therapy at months three and six was 2log₁₀ compared to little or no reduction in patients who withdrew from the study.

The investigators were encouraged by the outcome of their study, particularly their ability to “retain active substance users in a structured intervention.”

However, they note that only a third of patients remained on the study for six months. They suggest that future directly observed therapy programmes should screen for an individual’s willingness to take anti-HIV therapy and engage in a directly observed therapy. They also recommend that directly observed therapy should last for relatively brief periods such as three months.

“Modified directly observed therapy may not be the only ‘solution’ to managing non adherence”, conclude the investigators, adding “our results, however, support the finding that an observed therapy programme that can accommodate ever-changing life situations should be included in the spectrum of options to enhance adherence to HAART.”