Background: The 19-item Acne-QoL is a validated psychometric instrument designed for use in clinical trials.
Objective: The purpose of this study was to develop a condensed version of the Acne-QoL as an alternative measure of psychosocial impact for use in routine clinical practice.
Methods: Four condensed versions of the Acne-QoL were evaluated by regression analysis in a subset of 434 patients. The version with four items most broadly representative of acne-specific quality of life combined with a high level of correlation to Acne-QoL total score was selected for further validation in two different patient samples.
Results: The patient ranked condensation, representing items from each domain of greatest patient-perceived importance and relevance was selected for further analysis (Acne-Q(4)). The Acne-Q(4) explained 98.5% of the variation in total score of Acne-QoL. Validation of the Acne-Q(4) in a follow-up group and an independent subset of patients resulted in Pearson correlation coefficients of 0.967 (p<0.001). Construct validity of the Acne-Q(4) was confirmed by demonstrating a similar relationship as the Acne-QoL to acne severity.
Limitations: There is less breadth and detail of QoL information in the Acne-Q(4) than in the Acne-QoL. The analysis relied on a total score for Acne-QoL, which the original developers did not validate.
Conclusions: The Acne-Q(4) is accurately reflective of the parent instrument and may facilitate the psychometric evaluation of the impact of facial acne on patients in routine clinical practice by its practicality.