Major Finding: Researchers found only 13 studies that met their search criteria.
Data Source: A meta-analysis of studies published between Jan. 1, 1998 and Sept. 1, 2008.
Disclosures: The study was funded by Galderma Laboratories. Dr. Feldman said he has received funding and consulting fees from the company.
Medication adherence among acne patients is so poorly studied that it is difficult to draw any solid conclusions about the topic, results from a new meta-analysis suggest.
“That's a critical issue, because it would be nice to have new treatments, but getting people to be more compliant with existing drugs would be another great way to get people better,” one of the study authors, Dr. Steven R. Feldman, said in an interview. “We need more studies, especially those that tell us how to improve adherence.”
A recurring theme in some of the studies reviewed was that acne patients with a better quality of life tended to take their acne medication as prescribed. “Physicians think, 'acne really bothers teenagers, so they're going to be more likely to use their medicine,'” said Dr. Feldman of Wake Forest University, Winston-Salem, N.C. “In fact, we found that the people who were most bothered by their acne were least likely to use their medicine. Maybe psychologically they don't want to think about their disease. Who knows? But you can't just assume that people will use their medicines just because the disease bothers them.”
For the study, Dr. Feldman and his associates conducted a Medline search of articles published between Jan. 1, 1998, and Sept. 1, 2008, that contained the keywords acne and adherence or compliance (J. Cos. Dermatol. 2010;9:160-6).
The researchers found only 13 studies that met their criteria. Of these, six used patient questionnaires to measure adherence, two used patient diaries, and the remaining five used electronic medical records.
Investigators of the largest study in the review asked 2,221 patients to rate their acne medication adherence as daily, almost daily, or rarely (Dermatol. 2008;217:309-14). More than half (57%) rated their adherence as every day, and 38% rated it as almost every day. Forgetting to take the medication was the most common reason cited for low adherence, followed by a perceived lack of time.
A more recent study contained in the review measured acne medication adherence in 152 teens who returned for follow-up at 2 months (J. Cutan. Med. Surg. 2009;13:204-8). Patients were considered to have high adherence if they reported using their acne medication as prescribed 100% of the time, medium adherence 75%-99% of the time, and low adherence 74% of the time and below.
The investigators of this study reported that 24% of patients were rated as having high adherence, 49% had medium adherence, and 26% had low adherence. Patients rated side effects from the medication as the most common reason for low adherence, followed by forgetfulness.