Study: Questionnaire accurately measures ART
Clinicians could ask one question
One thing clinicians need as they work to keep their HIV patients adherent to their medication regimens is an accurate, simple tool for measuring drug adherence.
While there have been many complicated, costly, or inaccurate options over the past decade, there is research to suggest that at least one simple, self-reporting tool provides accurate adherence measurement.
The tool, called the AIDS Clinical Trial Group (ACTG) Adherence Questionnaire, has been extensively used, and now a study of the tool suggests it works well.1
"The measurement of ART is a critical component in our understanding of improving adherence," says Nancy Radcliffe Reynolds, PhD, professor at Yale University in New Haven, CT.
"Although we appreciate how critical ART adherence measurement is, we don't have a gold standard in the field," Reynolds adds. "Although self-reporting measures have been valued for their convenience and they've been found to be solid measures, they do overestimate the rate of adherence."
So a group of investigators developed a short instrument for measuring adherence, and Reynolds' recent research shows that it is useful as an adherence tool.
Most researchers who used the tool reported only the responses to the first question about how many doses the patient had missed yesterday, two days ago, three days ago, and four days ago, Reynolds says.
"There are other items in the questionnaire that measure adherence to instruction and other items that show how well people follow a schedule and instructions, and researchers were not doing anything with that data," Reynolds says.
Instead they would summarize answers to the first question and use that as the sole measure of adherence, she explains.
Reynolds wanted to find out if their approach was the best approach, or if it would be better to take all of the questionnaire's items into consideration.
"Do you need all of those items, and, if not, then let's take them out of the questionnaire," she says. "Our hypothesis was that because the full questionnaire captures broader multi-dimensions of adherence, then it would provide us with more comprehensive information."
Using three different measures for their analysis, including the self-report questionnaire, plasma RNA, and MEMS-cap data, they did a reliability assessment of the different items, Reynolds says.
"We found that all the items of the ACTG questionnaire had good reliability," she notes.
Further analysis led investigators to come up with two strategies: the first would be useful for clinicians who are looking for a very quick answer to whether a particular patient is adherent with his or her antiretroviral medications, and this is to ask just one question.
"What we recommend to clinicians based on our findings from this study is to just ask about the four day recall alone," Reynolds says. "But if they want a more precise measure with more variability, then we recommend four items."
The four questions are as follows:
- How many doses did you miss yesterday, 2 days ago, 3 days ago, 4 days ago?
- How closely do you follow your schedule? Never? Some? Half? Most?
- How closely do you follow instructions?
- When was the last time you skipped any medication?
The only caveat for the research is that it used data from patients who were on the older, more complex ART regimens, Reynolds notes.
"We're not sure it's as necessary to use the more global measures of how well you follow instructions and follow a schedule with the newer medications," she explains. "With the older medications the timing was quite important, so asking the more global questions provided more information about the time factor and added another dimension to their adherence behavior."
The take-home message is that self-reported adherence measures can be quite strong, even with the typical inflation, Reynolds says.
"For someone who finds the cost of MEMS-cap prohibitive, this could be a really nice, strong measure of adherence," she adds.
Reference
- Reynolds NR, Sun J, Nagaraja HN, et al. Optimizing measurement of self-reported adherence with the ACTG Adherence Questionnaire, a cross-protocol analysis. Acquir Immune Defic Syndr. 2007;46(4):402-409.
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