title: Cluster analysis and prediction of treatment outcomes for chronic rhinosinusitis.
abstract: BACKGROUND
  Current clinical classifications of chronic rhinosinusitis (CRS) have weak prognostic utility regarding treatment outcomes. Simplified discriminant analysis based on unsupervised clustering has identified novel phenotypic subgroups of CRS, but prognostic utility is unknown.
  
  
  OBJECTIVE
  We sought to determine whether discriminant analysis allows prognostication in patients choosing surgery versus continued medical management.
  
  
  METHODS
  A multi-institutional prospective study of patients with CRS in whom initial medical therapy failed who then self-selected continued medical management or surgical treatment was used to separate patients into 5 clusters based on a previously described discriminant analysis using total Sino-Nasal Outcome Test-22 (SNOT-22) score, age, and missed productivity. Patients completed the SNOT-22 at baseline and for 18 months of follow-up. Baseline demographic and objective measures included olfactory testing, computed tomography, and endoscopy scoring. SNOT-22 outcomes for surgical versus continued medical treatment were compared across clusters.
  
  
  RESULTS
  Data were available on 690 patients. Baseline differences in demographics, comorbidities, objective disease measures, and patient-reported outcomes were similar to previous clustering reports. Three of 5 clusters identified by means of discriminant analysis had improved SNOT-22 outcomes with surgical intervention when compared with continued medical management (surgery was a mean of 21.2 points better across these 3 clusters at 6 months, P < .05). These differences were sustained at 18 months of follow-up. Two of 5 clusters had similar outcomes when comparing surgery with continued medical management.
  
  
  CONCLUSIONS
  A simplified discriminant analysis based on 3 common clinical variables is able to cluster patients and provide prognostic information regarding surgical treatment versus continued medical management in patients with CRS.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC.
authors.forename: Zachary M
authors.initials: ZM
authors.lastname: Soler
authors.affiliation: Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC.
authors.forename: J Madison
authors.initials: JM
authors.lastname: Hyer
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Luke
authors.initials: L
authors.lastname: Rudmik
authors.affiliation: Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Ramakrishnan
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Oregon Health Sciences University, Portland, Ore.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Smith
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, SC. Electronic address: schlossr@musc.edu.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Schlosser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002908:Chronic Disease; D000066491:Clinical Decision-Making / Q000379:methods*; D016000:Cluster Analysis; D003661:Decision Support Techniques; D016002:Discriminant Analysis; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life; D019141:Respiratory System Agents / Q000627:therapeutic use*; D012220:Rhinitis / Q000188:drug therapy* / Q000601:surgery*; D012852:Sinusitis / Q000188:drug therapy* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019141:Respiratory System Agents
keywords: Chronic rhinosinusitis; cluster; outcomes; prediction; quality of life; sinusitis; treatment