A pilot quality-of-life instrument for acne rosacea

Background No rosacea-specific quality-of-life (QOL) instrument exists. Objective We sought to develop a validated, reliable rosacea-specific instrument. Methods From 6 in-depth interviews, we composed 21 rosacea-specific items. These items and Skindex-29 were administered in a validation cohort (n = 59). Internal consistency reliability and reproducibility were measured with Cronbach's coefficient α and intraclass correlation coefficient, respectively. Responsiveness was assessed comparing baseline with 4- to 6-month responses. Construct validity was assessed with principal axes factor analyses. Discriminant validity was examined with an additional 38 patients comparing differences in responsiveness between the rosacea-specific QOL instrument and Skindex. Results Reliability was high (Cronbach's α: 0.82-0.97, intraclass correlation coefficient: 0.70-0.95). The rosacea-specific QOL instrument showed preliminary responsiveness for patients with improved disease ( P ≤ .05). Principal axes factor analyses correlated to hypothesized scales ( r = 0.57-0.82). Discriminant validity was illustrated with greater differences in responsiveness using the rosacea-specific QOL instrument ( P = .008). Limitations Potential selection bias and lack of generalizability was a limitation. Conclusions The rosacea-specific QOL instrument, RosaQoL, appears to be a reliable and valid QOL instrument and shows preliminary responsiveness for patients with improving rosacea.