Direct and Indirect Effects of Crisaborole Ointment on Quality of Life in Patients with Atopic Dermatitis: A Mediation Analysis

Crisaborole ointment is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis. Using pooled data from two phase 3 studies (NCT02118766/NCT02118792), mediation modeling determined the interrelationship among pruritus, quality of life (QoL), and treatment. Patients aged ≥ 2 years received crisaborole ointment 2% or vehicle twice daily for 28 days. QoL measures were Dermatology Life Quality Index (DLQI) (≥ 16 years) and Children's Dermatology Life Quality Index (CDLQI) (2-15 years). Pruritus was assessed by the Severity of Pruritus Scale (4-point scale from 0 to 3). The indirect effect of crisaborole on QoL mediated through its effect on pruritus was 51% (DLQI model, p < 0.05) and 72% (CDLQI model, p < 0.05). Direct effect (other effects) on QoL was 49% (DLQI model, p < 0.05) and 28% (CDLQI model, p > 0.05). Mediation modeling shows that crisaborole affects QoL mostly indirectly through pruritus severity reduction.