title: Understanding the Relationship Between Pruritus Severity and Work Productivity in Patients With Moderate-to-Severe Psoriasis: Sleep Problems Are a Mediating Factor.
abstract: 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
  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.
  
  
  CONCLUSIONS
  Sleep may mediate the role of pruritus on work productivity, but both factors appear to have independent negative effects on work.
authors.forename: A B
authors.initials: AB
authors.lastname: Kimball
authors.forename: E
authors.initials: E
authors.lastname: Edson-Heredia
authors.forename: B
authors.initials: B
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.forename: T
authors.initials: T
authors.lastname: Maeda-Chubachi
authors.forename: W
authors.initials: W
authors.lastname: Shen
authors.forename: M T
authors.initials: MT
authors.lastname: Bianchi
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011537:Pruritus / Q000175:diagnosis* / Q000453:epidemiology; D011565:Psoriasis / Q000175:diagnosis* / Q000453:epidemiology; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000453:epidemiology; D000066477:Work Performance