WESTPORT, CT (Reuters Health) - Electronic monitoring is superior to
self-reporting in the assessment of HIV-infected drug users' adherence to
antiretroviral treatment, and it should be used in adherence intervention
studies, according to a report in the October 15th issue of Clinical
But in everyday practice, a careful 1-day self-report to assess drug
adherence is valuable, lead investigator Dr. Julia H. Arnsten told Reuters
Health. New study results show that "what [patients] did in the past day
accurately predicts what they did over time," she said.
Dr. Arnsten, who is at Montefiore Medical Center in Bronx, New York, and
compared self-reported and electronically monitored adherence in 67
HIV-infected current and former drug users. Electronic monitoring was
accomplished with Medication Event Monitoring Systems (MEMS, Aprex
Corporation), a microchip-bearing pill bottle cap that records the date and
time the bottle is opened.
According to the report, the mean self-reported adherence rate for the day
preceding the followup visit (79%) and the rate for the week preceding each
visit (78%) were significantly higher than mean adherence as measured by MEMS
(57% and 53%, respectively). The two measures of adherence were correlated
with each other and with adherence over time.
Adherence did not differ significantly for different medications, the authors
report, and, somewhat surprisingly, adherence rates were not lower for
regimens with a higher pill burden. The authors note that the study was not
randomized, and "physicians may have chosen complex regimens only for
patients they deemed 'good adherers'."
MEMS adherence better predicted viral load than self-reported adherence. But
Dr. Arnsten told Reuters Health, "We showed a strong correlation between
self-reported adherence and viral load, so self-report is an accurate
predictor of viral load, and probably the likelihood of emerging resistance,
even though it inflates adherence rates by 20% to 30%."