title: Hospitalization, inpatient burden and comorbidities associated with bullous pemphigoid in the U.S.A.
abstract: BACKGROUND
  Bullous pemphigoid (BP) is associated with significant disability and comorbid health disorders that may lead to or result from hospitalization. However, little is known about the inpatient burden and comorbidities of BP.
  
  
  OBJECTIVE
  To obtain data on the inpatient burden and comorbidities of BP in the U.S.A.
  
  
  METHODS
  We analysed data from the 2002 to 2012 National Inpatient Sample, including a representative 20% sample of all hospitalizations in the U.S.A. (72 108 077 adults).
  
  
  RESULTS
  The prevalence of hospitalization for BP increased from 25·84 to 32·60 cases per million inpatients from 2002 to 2012. In multivariate logistic regression models with stepwise selection, increasing age, nonwhite ethnicity, higher median household income, being insured with Medicare or Medicaid, and increasing number of chronic conditions were all associated with hospitalization for BP (P < 0·05 for all). The top three primary discharge diagnoses for patients with a secondary diagnosis of BP were septicaemia (prevalence 5·51%, 95% confidence interval 5·03-5·99), pneumonia (4·60%, 4·19-5·01) and urinary tract infection (3·52%, 3·15-3·89). Patients with BP also had numerous autoimmune, infectious, cardiovascular and other comorbidities. Interestingly, BP was associated with multiple neuropsychiatric disorders, including demyelinating disorders, dementias (presenile, senile, vascular and other), paralysis, neuropathy (diabetic, other polyneuropathy), Parkinson disease, epilepsy, psychoses and depression. The mean annual age- and sex-adjusted in-hospital mortality rate was significantly higher in patients with a secondary diagnosis of BP compared with no BP (2·9%, range 2·8-3·9% vs. 2·1%, range 1·9-2·2%). Significant predictors of mortality in patients with BP included increasing age, nonwhite ethnicity and insurance with Medicaid or other payment status (P < 0·05 for all).
  
  
  CONCLUSIONS
  Hospitalization for BP increased significantly between 2002 and 2012. Moreover, there were significant ethnic and healthcare disparities with respect to hospitalization and inpatient mortality from BP.
authors.affiliation: Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, U.S.A.|The Graduate School, Northwestern University, Chicago, IL, 60611, U.S.A.
authors.forename: Z
authors.initials: Z
authors.lastname: Ren
authors.affiliation: Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, U.S.A.
authors.forename: D Y
authors.initials: DY
authors.lastname: Hsu
authors.affiliation: Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, U.S.A.
authors.forename: J
authors.initials: J
authors.lastname: Brieva
authors.affiliation: Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, U.S.A.
authors.forename: N B
authors.initials: NB
authors.lastname: Silverberg
authors.affiliation: Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, U.K.
authors.forename: S M
authors.initials: SM
authors.lastname: Langan
authors.affiliation: Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, U.S.A.|Departments of Preventive Medicine and Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, U.S.A.
authors.forename: J I
authors.initials: JI
authors.lastname: Silverberg
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015331:Cohort Studies; D015897:Comorbidity; D017281:Cost of Illness; D003365:Costs and Cost Analysis; D005260:Female; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007902:Length of Stay / Q000191:economics / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010391:Pemphigoid, Bullous / Q000191:economics / Q000401:mortality / Q000628:therapy*; D014481:United States / Q000453:epidemiology; D055815:Young Adult