Medical adherence to acne therapy: a systematic review

Poor adherence of acne patients to treatment may equate to poor clinical efficacy, increased healthcare costs, and unnecessary treatments. Authors have investigated risk factors for poor medical adherence and how to improve this difficult problem in the context of acne.

This systematic review aims to describe what methods have been used to measure adherence, what is known about acne patients' adherence to treatment, and the factors affecting adherence.

A MEDLINE search was performed for randomized controlled trials published between 1978 and June 2013, focusing on patient adherence to prescribed acne medications. A test for equality of proportions was performed on studies of similar design to collectively analyze adherence to oral versus topical medication. The self-reported adherence data collected from these clinical trials were then compared with adherence data from a pharmacy database study.

Studies varied in modalities of data collection, but the majority utilized subjective methods. Topical therapies were more often studied than oral. The overall oral adherence rate, as calculated by a test of equality of proportions, was 76.3%, while the overall topical adherence rate was 75.8% (p=0.927). The occurrence of side effects and young age were cited as the top reasons for poor adherence, followed by forgetfulness.

The MEDLINE search resulted in a limited sample of adherence studies. In addition, there is currently no standardized or fully validated method of measurement, allowing for variability in what was considered 'adherent'. Lastly, data collected via subjective methods cannot guarantee reliable results.

Overall, the values reflected a population adherent to both topical and oral medications, with no significant difference in adherence between the two. However, the methodologies used by many of the studies were weak, and the findings are not consistent with results of more objective measures of adherence. The leading factors that contribute to poor adherence may be reduced with enhanced patient consultation, reminder systems, and education.