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 Infectious Diseases.
 
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 colleagues 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%."