NailQoL: a quality-of-life instrument for onychomycosis

Background The disease burden onychomycosis is not trivial. The aim is to develop a quality of life instrument to measure the onychomycosis burden. Methods 402 patients with mycologically-confirmed onychomycosis completed a baseline questionnaire of 39 quality of life items (modified Skindex-29 questions and 10 additional nail-specific questions). Internal consistency, reproducibility and responsiveness of the final instrument, NailQoL were measured. Results 15 items consisting of symptom (3), emotion (10), and functional (2) domains were retained in NailQoL. Symptom and emotion subscales = 0.80-0.92. Administration alpha demonstrated good internal consistency (Cronbach's of the instrument to 46 patients at one month after baseline revealed good reproducibility (ICC 0.88-0.91). Responsiveness was measured in 292 patients at 18 months; statistically significant better NailQoL scores were found in individuals with complete cure (mycological and clinical) (P < 0.01). Conclusion NailQoL represents a new concise, valid, reliable, and responsive instrument for measuring burden of skin disease for patients with onychomycosis.