Quality of life assessment in cosmetics: specificity and interest of the international <i>BeautyQol</i> instrument

The wide use of cosmetics and their perceived benefits upon well-being imply objective descriptions of their effects upon the different dimensions contributing to the quality of life (QoL). Such a goal pleas for using relevant and validated scientific instruments with robust measurement methods. This paper discusses the interest of the new validated questionnaire BeautyQoL specifically designed to assess the effect of cosmetic products on physical appearance and QoL. After conducting a review of skin appearance and QoL, three phases of the international codevelopment have been carried out in the following sequence: semi-directed interviews (Phase 1), acceptability study (Phase 2), and validation study (Phase 3). Data collection and validation process have been carried out in 16 languages. This review confirms that QoL instruments developed in dermatology are not suitable to assess cosmetic products, mainly because of their lack of sensitivity. General acceptability of BeautyQol was very good. Forty-two questions have been structured in five dimensions that explained 76.7% of the total variance: Social Life, Self-confidence, Mood, Vitality, and Attractiveness. Cronbach's alpha coefficients are between 0.932 and 0.978, confirming the good internal consistency of the results. The BeautyQol questionnaire is the first international instrument specific to cosmetic products and physical appearance that has been validated in 16 languages and could be used in a number of clinical trials and descriptive studies to demonstrate the added value of these products on the QoL.