title: The Comparative Burden of Chronic Widespread Pain and Fibromyalgia in the United States.
abstract: Little information exists on the comparative patient and economic burden of chronic widespread pain (CWP) and fibromyalgia (FM) in the United States.
  
  
  
  This multistage, observational study included an online screening survey of a large geographically diverse US sample to assess CWP status, a physician/site visit to determine FM diagnosis, and an online subject questionnaire to capture clinical characteristics, pain, health status, functioning, sleep, healthcare resource use (HRU), productivity, and costs. Based on the screener and physician evaluation, mutually exclusive groups of subjects without CWP (CWP-), with CWP but without FM (CWP+), and with confirmed FM were identified.
  
  
  
  Disease burden was examined in 472 subjects (125 CWP-, 176 CWP+, 171 FM). Age, race, and ethnicity were similar across groups. Mean body mass index and number of comorbidities increased from CWP- to CWP+ to FM (P = 0.0044, P < 0.0001, respectively). From CWP- to CWP+ to FM, there were reductions in health status (EQ-5D, SF-12) and sleep outcomes (MOS-SS, SSQ) (all P < 0.05). Pain severity, interference with function (BPI-SF), and overall work impairment (WPAI:SHP) increased from CWP- to CWP+ to FM (all P < 0.0001). Higher proportions of CWP+ (52.8%) and FM subjects (62.6%) were taking pain-related prescription medications relative to CWP- subjects (32.8%; P < 0.0001). Significant differences in total direct and indirect costs across the three groups (both P < 0.0001) were observed, with highest costs among FM subjects.
  
  
  
  Fibromyalgia subjects were characterized by the greatest disease burden with more comorbidities and pain-related medications, poorer health status, function, sleep, lower productivity, and higher costs.
authors.affiliation: Covance Market Access Services Inc, Gaithersburg, MD, U.S.A.
authors.forename: Caroline
authors.initials: C
authors.lastname: Schaefer
authors.affiliation: Covance Market Access Services Inc, San Diego, CA, U.S.A.
authors.forename: Rachael
authors.initials: R
authors.lastname: Mann
authors.affiliation: Pfizer Inc, New York, NY, U.S.A.
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Masters
authors.affiliation: Pfizer Inc, Groton, CT, U.S.A.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Cappelleri
authors.affiliation: Covance Market Access Services Inc, Conshohocken, PA, U.S.A.
authors.forename: Shoshana R
authors.initials: SR
authors.lastname: Daniel
authors.affiliation: Pfizer Inc, New York, NY, U.S.A.
authors.forename: Gergana
authors.initials: G
authors.lastname: Zlateva
authors.affiliation: Covance Market Access Services Pty Ltd, Sydney, NSW, Australia.
authors.forename: Heather J
authors.initials: HJ
authors.lastname: McElroy
authors.affiliation: Pfizer Inc, New York, NY, U.S.A.
authors.forename: Arthi B
authors.initials: AB
authors.lastname: Chandran
authors.affiliation: Covance Market Access Services Inc, Gaithersburg, MD, U.S.A.
authors.forename: Edgar H
authors.initials: EH
authors.lastname: Adams
authors.affiliation: Pfizer Inc, Groton, CT, U.S.A.
authors.forename: Annlouise R
authors.initials: AR
authors.lastname: Assaf
authors.affiliation: Aurora Pain Program, Milwaukee, WI, U.S.A.
authors.forename: Michael
authors.initials: M
authors.lastname: McNett
authors.affiliation: Swedish Medical Center and University of Washington, Seattle, WA, U.S.A.
authors.forename: Philip
authors.initials: P
authors.lastname: Mease
authors.affiliation: Cedars-Sinai Medical Center, Los Angeles, CA, U.S.A.
authors.forename: Stuart
authors.initials: S
authors.lastname: Silverman
authors.affiliation: University of Florida, Gainesville, FL, U.S.A.
authors.forename: Roland
authors.initials: R
authors.lastname: Staud
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059350:Chronic Pain / Q000453:epidemiology*; D015897:Comorbidity; D017281:Cost of Illness; D004526:Efficiency; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis / Q000453:epidemiology*; D017048:Health Care Costs / Q000706:statistics & numerical data; D006295:Health Resources / Q000706:statistics & numerical data; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D012890:Sleep; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: burden of illness; chronic pain; costs; fibromyalgia; health-related quality of life; healthcare resource utilization; patient-reported outcomes; productivity