People with HIV who have their viral load and
CD4 cell count monitored every six months were no more likely to experience
virological failure or to change their antiretroviral regimens than those
monitored every four months, researchers reported at the IDWeek 2013 meeting
last week in San Francisco.
European and US HIV treatment guidelines have
traditionally recommended that people receiving antiretroviral therapy (ART) should
have their viral load and CD4 count monitored as often as every three months.
Current guidelines note that less frequent monitoring may be adequate for
patients who are doing well, but this has not been extensively studied in
Kamla Sanasi from the University of South Carolina and colleagues designed a
study to compare outcomes amongst people with HIV on stable ART who were
randomly assigned to undergo laboratory monitoring every four or every six
Less frequent monitoring could reduce cost and improve quality of life by
requiring fewer medical appointments but, conversely, adherence could decline
and virological failure or toxicities could continue longer before they are
detected, the researchers noted as background.
This analysis included 165 people with HIV seen at a single clinic in the
US south who had CD4 counts of at least 250 cells/mm3 and were on
combination ART with an undetectable viral load (<200 copies/ml) for at least
one year. All patients who met these criteria were included, not only those who
were expected to do well with less frequent monitoring.
Most participants (about 70%) were men, nearly 60% were black, 38% were
white, the average age was 47 years, and they had been HIV positive for an
average of 12 years. Nearly half were taking non-nucleoside reverse
transcriptase inhibitors (NNRTIs) and one-third were taking protease
inhibitors. The mean baseline CD4 count was approximately
575 cells/mm3, with a nadir (lowest-ever) of 244 cells/mm3. One-quarter had two or more
co-morbid conditions, including 15% with hepatitis B and 17% with hepatitis C.
At each scheduled visit, participants completed an adherence
survey, a quality-of-life questionnaire that included physical and mental health
components, and a questionnaire about other medical care they received. Follow-up
continued for an average of 20 months.
The primary study endpoint was
percentage of participants with virological failure at two years, defined as
two consecutive detectable viral loads. Other outcomes included self-reported
adherence, quality of life, number of healthcare visits, emergence of new viral
resistance mutations, and percentage of people who needed to change or stop ART.
There were no significant differences
in the proportion of participants with virological failure, nor in time-to-virological-failure in the four-month and six-month monitoring groups. In fact,
only a single participant in the six-month group experienced sustained HIV
Quality of life was also the same in
both groups, with similar physical health scores (54 vs 53) and mental health
scores (51 in both groups). Scores did not change significantly from baseline
in either group.
Participants also reported no
difference in adherence in the six-month and four-month monitoring groups
(adherence scores of 12 vs 13). Again, adherence did not change significantly
from baseline in either group.
Only a small proportion of
participants changed or stopped ART, with no significant differences between
the four-month and six-month groups. Two people switched regimens due to viral
breakthrough, one due to poor adherence and twelve for other reasons; none changed
to due side-effects. One person in each group acquired a new resistance
"At follow up, there was no difference in virologic failure,
quality of life scores, time to detectable viral load, or change in HAART when
stable patients are monitored every six months versus every four months,"
the investigators concluded. "Monitoring stable HIV patients
on HAART with undetectable viral loads every six months is safe."
randomised to monitoring every four months actually had 23% more HIV-related
medical visits overall, a significant difference. The 16% increase in non-HIV-related
visits did not reach statistical significance, however, leading the researchers
to surmise that, "Patients
with longer intervals between HIV visits did not compensate with more visits to
findings have potential implications for healthcare policies and resource
utilisation, the study team concluded. At their clinic, which sees about 2000
patients, reducing monitoring for stable individuals from three to two visits
per year would save more than USD$787,000 annually. These funds could be
redirected to HIV screening, linkage to care, adherence counselling and other
social issues, they suggested.
On a national
level in the US, a recent study by Emily Hyle and colleagues found that reducing CD4 cell monitoring for
stable patients from every six months to once a year could save USD$10.2
million annually, or more than USD$225 million over a lifetime.
After the presentation Paul Volberding from the
University of California in San Francisco noted that some experts are talking
about not monitoring CD4 counts at all in stable patients, just viral load. This
approach has been studied with good results in resource-limited settings where regular CD4
monitoring is not logistically feasible. More recently, a US study found that there was a 99% probability that people
with viral load suppression and a CD4 count above 300 cells/mm3 would maintain a CD4 level well above the danger zone for opportunistic
infections over five years.