The number of outcome measures used to assess disease severity and quality of life (QOL) in randomized controlled trials of patients with atopic dermatitis (AD) has risen in recent years, according to a systematic review reports.

An overall lack of standardization of these outcome measures, however, is hindering the synthesis and translation of research into clinical practice, reported Mary K. Hill of the University of Colorado, Aurora, and her associates.

“Standardization of disease severity and QOL outcome instruments is essential for comparability among studies and improved quality of research evidence,” they wrote (J Am Acad Dermatol. 2016 Nov;75[5]:906-17. doi: 10.1016/j.jaad.2016.07.002).

Their systematic review of 135 randomized controlled trials (RCTs) identified 62 disease-severity and 28 quality-of-life instruments used in studies of patients with AD between July 2010 and July 2015.

This was a drastic increase from the 20 disease severity scales and 14 QOL indices identified in a previous systematic review of 382 RCTs of AD therapies conducted between 1985 and 2010, they noted.

In their review, the most frequently used disease severity scale was the Scoring Atopic Dermatitis (SCORAD) index, which was used in 79 studies. That was followed by the visual analogue scale (VAS) for pruritus, used in 30 studies; the Investigator’s Global Assessment (IGA) tool, used in 29 studies; and the Eczema Area and Severity Index (EASI), used in 28 studies.

But despite the well-documented burden of AD, the researchers noted that only 33% of the RCTs they reviewed assessed QOL. “This is up from the 18% of RCTs on AD that reported QOL outcomes between 1985 and July 2010, perhaps signifying gradually increased attention to patient emotional well-being,” Ms. Hill and her associates wrote.

A trend described by the authors, however, as “perhaps the most disconcerting” was that 75% of identified QOL instruments were used only once. “Continued increases in the reporting of QOL outcomes will be of limited benefit for interstudy comparisons if the diversity of measures used also continues to rise,” they said.

Adding to the confusion, the researchers found frequent overlap in the naming and content of instruments used in studies, making it even more challenging to identify meaningful comparisons.

There was no funding source, and the authors had no conflicts of interest to declare.