Pharmacy data can be used as a simple low-cost tool
for monitoring a patient's adherence to HIV therapy in
resource-limited areas, according to a study by researchers
from the Johns Hopkins
Bloomberg School of Public Health and other
organizations. Their article was published in the April 17
issue of Annals of Internal Medicine.
In the late 1990s, the most well-known and recommended
HIV treatment — highly active antiretroviral therapy,
known as HAART — was difficult to maintain due to the
high number of pills that patients must take and the
complex schedule they must follow in order to see benefits.
The study authors set out to assess the relationship
between adhering to a new HIV treatment known as
NNRTI-based HAART (for non-nucleoside reverse transcriptase
inhibitor) and viral load.
Viral load measures the amount of viruses present in a
given volume of blood. Public health practitioners advocate
a high level of adherence to treatment because people with
lower viral load levels are less infectious to others.
"Although maximal adherence to NNRTI-based HAART is
optimal, moderate levels of adherence to NNRTI-based HAART
leads to sustained viral suppression as well," said Jean
Nachega, lead author of the study and an assistant
scientist in the Bloomberg School's Department of International
Health. "However, we do not advise patients to reduce
their HAART compliance. Our study shows that a maximum
level of adherence is still optimal for decreasing the risk
of HIV complications, such as drug resistance and disease
progression, and death."
The study, conducted in South Africa, included 2,821
adults infected with HIV. Adherence to NNRTI-based HAART
was assessed by reviewing monthly pharmacy claim reports.
Patients who filled at least 50 percent of antiretroviral
drug prescriptions had improved virologic outcomes,
compared to patients who filled fewer prescriptions. For
each 10 percent increase in pharmacy claim adherence beyond
50 percent, the researchers report an additional 10 percent
maintenance of viral suppression over a median 2.2
years.
"This is the first validation of pharmacy data as a
simple low-cost HAART adherence monitoring tool to predict
HIV-1 viral load response in sub-Saharan Africa," Nachega
said. "We think that the currently expanding President's
Emergency Plan for AIDS Relief and the United Nations
Global Fund to Fight AIDS, Tuberculosis and Malaria
antiretroviral therapy program in Africa should consider
using this simple, valid, low-cost adherence-monitoring
tool."
In an editorial in the same issue of Annals of
Internal Medicine, Julio S.G. Montaner, director of the
British Columbia Centre for Excellence in HIV/AIDS, stated,
"Expansion of HAART programs in South Africa and other low-
and medium-income nations ... must have appropriate tools
to monitor their evolution and impact. ... Refills or
claims data are reliable and valid indicators of actual
patient adherence. Although it may be premature to
generalize beyond these studies, this approach — if
appropriately and independently validated — could
become an important tool to evaluate HAART adherence in
public-sector programs in low- and medium-income
nations."