Understanding the Relationship Between Pruritus Severity and Work Productivity in Patients With Moderate-to-Severe Psoriasis: Sleep Problems Are a Mediating Factor.

BACKGROUND

Psoriasis is a debilitating skin disease associated with substantial pruritus, work impairment, and sleep disturbance.

OBJECTIVE

This study evaluated associations between pruritus and work productivity, and the role of sleep problems as a possible mediator of the relationship between the two.

METHODS AND MATERIALS

Data from a pruritus visual analog scale (Itch VAS), the Medical Outcomes Study Sleep Scale (MOS-SS), and the Work Productivity and Activity Impairment Questionnaire (WPAI) were collected in a phase 2 clinical trial in patients with psoriasis treated with ixekizumab or placebo. Mediating effects of sleep were tested in multiple regressions with pruritus severity (independent variable) and work productivity (dependent variable). Sobel tests evaluated the significance of sleep's effect.

RESULTS

Several MOS-SS domains were significantly associated with the WPAI presenteeism, work productivity, and activity impairment scores, and decreased the effect of pruritus. Sobel tests indicated that the Sleep Problems Index I had a significant effect (P<.05) in mediating the relationship between pruritus and presenteeism, work productivity, and activity impairment.

CONCLUSION

Sleep may mediate the role of pruritus on work productivity, but both factors appear to have independent negative effects on work.