title: Health care utilization patterns and costs for patients with hidradenitis suppurativa.
abstract: OBJECTIVE
  Hidradenitis suppurativa (HS) is a chronic cutaneous disease with acutely painful flares that require appropriate and timely treatment.
  
  
  OBJECTIVE
  To assess how individuals with HS utilize medical care, especially emergency department (ED) care, a high-cost setting, and to describe the health care costs for this group.
  
  
  METHODS
  Cohort cost-identification study of 150 493 individuals with claims from the MarketScan medical claims database. Patients with claims for HS and psoriasis (16 736 and 110 266, respectively) and a control group with neither condition (23 491) during the study period, January 2008 to December 2010, were included.
  
  
  METHODS
  An HS cohort was formed from all the patients who had 2 or more claims for HS (International Classification of Diseases, Ninth Revision [ICD-9] code 705.83) during the 3-year period. A psoriasis cohort was used as a comparison group, since it is another chronic inflammatory condition with prominent skin findings. This group included randomly selected patients who had 2 or more claims for psoriasis (ICD-9 code 696.1) during the 3-year period. A second control group included randomly selected patients who had no claims for either condition during the 3-year period. From these cohorts only patients that were continuously enrolled for the 3-year period were included.
  
  
  METHODS
  Health care utilization measures including inpatient length of stay, emergency department and outpatient visits, and number of days supplied of prescription medication were investigated. Cost variables were also investigated and included inpatient, outpatient, emergency department, prescription drug, and total all-cause health care expenditures, which were adjusted for inflation and reported in 2010 US dollars.
  
  
  RESULTS
  The largest component of the total 3-year cost for the HS group was inpatient cost (37.4%). In contrast, for the psoriasis group this was drug costs (46.5%) and for the control group, inpatient costs (40.9%). The proportion of people who were hospitalized in the HS cohort (15.8%) was higher than the psoriasis (10.8%) or control (8.6%) groups (P < .001). The proportion of patients who used the ED over the 3-year period was higher in the HS cohort (27.1%) than the psoriasis (17.4%) or control groups (17.2%) (P < .001). Similarly, the mean (SD) 3-year ED cost for the HS group was $2002 ($6632) and was higher than both comparison groups (P < .001). After adjustment for age, sex, and comorbidities, ED utilization remained higher in the HS group compared with the control (P < .001) and psoriasis (P = .02) cohorts.
  
  
  CONCLUSIONS
  Hidradenitis suppurativa affects a younger, predominantly female population of patients. High-cost settings, such as ED and inpatient care, are used more frequently for patients with HS. Both patients and clinicians should be aware of this finding, and further research is needed to investigate the impact of health care utilization on patient outcomes.
authors.affiliation: Department of Dermatology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.
authors.forename: Joslyn S
authors.initials: JS
authors.lastname: Kirby
authors.affiliation: Department of Dermatology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.
authors.forename: Jeffery J
authors.initials: JJ
authors.lastname: Miller
authors.affiliation: Department of Dermatology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania.
authors.forename: David R
authors.initials: DR
authors.lastname: Adams
authors.affiliation: Department of Public Health Sciences, Penn State Hershey, Hershey, Pennsylvania.
authors.forename: Douglas
authors.initials: D
authors.lastname: Leslie
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003365:Costs and Cost Analysis; D004636:Emergency Service, Hospital / Q000191:economics / Q000706:statistics & numerical data; D005260:Female; D017497:Hidradenitis Suppurativa / Q000191:economics* / Q000628:therapy*; D006760:Hospitalization / Q000191:economics; D006801:Humans; D008297:Male; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D012189:Retrospective Studies