title: National trends in retropharyngeal abscess among adult inpatients with peritonsillar abscess.
abstract: OBJECTIVE
  To describe national trends in retropharyngeal abscess (RPA) complicating peritonsillar abscess (PTA) and to determine factors associated with RPA in patients with PTA.
  
  
  METHODS
  Cross-sectional analysis.
  
  
  METHODS
  Nationwide Inpatient Sample, 2003-2010.
  
  
  METHODS
  PTA patients ≥18 years old, with or without RPA, were extracted according to ICD-9-CM codes. The cohort was analyzed with descriptive statistics and multivariate regression modeling to identify factors associated with RPA.
  
  
  RESULTS
  Of the 91,647 (95% CI: 86,433-95,449) patients identified with PTA, 885 (1.0%) also had a concurrently coded RPA. The annual rate of concomitant RPA increased from 0.5% (95% CI: 0.3%-0.8%) to 1.4% (95% CI: 1.0%-2.0%) between 2003 and 2010 (P < .001). PTA patients with RPA more frequently underwent tonsillectomy (23.5% vs 11.1%), endotracheal intubation (7.1% vs 1.5%), and mechanical ventilation (13.2% vs 2.0%) than those without RPA (all P < .001). PTA patients with RPA were significantly older (41 vs 34 years old), had a longer hospital stay (6.4 vs 2.5 days), and had more procedures (2.5 vs 0.9) when compared to patients without RPA (all P < .001). Upon multivariate regression analysis, factors associated with RPA included the age groups of 40 to 64 years (odds ratio, 2.256; P < .001) and 65 and older (odds ratio, 2.086; P = .045). Median total charges for PTA inpatients with concomitant RPA were approximately $8700 greater (P < .001) when compared to patients with PTA alone.
  
  
  CONCLUSIONS
  The incidence of RPA among adult inpatients with PTA is increasing, and patients with RPA have higher in-hospital resource utilization. Further studies may help validate factors predictive of RPA to enable prevention or earlier identification.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA hannan-qureshi@fsm.northwestern.edu.
authors.forename: Hannan A
authors.initials: HA
authors.lastname: Qureshi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Elisabeth H
authors.initials: EH
authors.lastname: Ference
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Bruce K
authors.initials: BK
authors.lastname: Tan
authors.affiliation: Vanderbilt Department of Otolaryngology, Bill Wilkerson Center, Nashville, Tennessee, USA.
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Chandra
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Kern
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA Center for Healthcare Studies, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Stephanie Shintani
authors.initials: SS
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D006801:Humans; D008875:Middle Aged; D000039:Peritonsillar Abscess / Q000150:complications / Q000453:epidemiology* / Q000601:surgery*; D017703:Retropharyngeal Abscess / Q000150:complications / Q000453:epidemiology* / Q000601:surgery*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Healthcare Cost and Utilization Project; Nationwide Inpatient Sample; peritonsillar abscess; retropharyngeal abscess