title: Sub-grouping patients with non-specific low back pain based on cluster analysis of discriminatory clinical items.
abstract: OBJECTIVE
  To identify potential subgroups amongst patients with non-specific low back pain based on a consensus list of potentially discriminatory examination items.
  
  
  METHODS
  Exploratory study.
  
  
  METHODS
  A convenience sample of 106 patients with non-specific low back pain (43 males, 63 females, mean age 36 years, standard deviation 15.9 years) and 7 physiotherapists.
  
  
  METHODS
  Based on 3 focus groups and a two-round Delphi involving 23 health professionals and a random stratified sample of 150 physiotherapists, respectively, a comprehensive examination list comprising the most "discriminatory" items was compiled. Following reliability analysis, the most reliable clinical items were assessed with a sample of patients with non-specific low back pain. K-means cluster analysis was conducted for 2-, 3- and 4-cluster options to explore for meaningful homogenous subgroups.
  
  
  RESULTS
  The most clinically meaningful cluster was a two-subgroup option, comprising a small group (n = 24) with more severe clinical presentation (i.e. more widespread pain, functional and sleeping problems, other symptoms, increased investigations undertaken, more severe clinical signs, etc.) and a larger less dysfunctional group (n = 80).
  
  
  CONCLUSIONS
  A number of potentially discriminatory clinical items were identified by health professionals and sub-classified, based on a sample of patients with non-specific low back pain, into two subgroups. However, further work is needed to validate this classification process.
authors: Department of Physiotherapy, Technological Educational Institute (TEI) of Patras, Greece. billis@teilam.gr
authors: Evdokia
authors: E
authors: Billis
authors: Christopher J
authors: CJ
authors: McCarthy
authors: Chris
authors: C
authors: Roberts
authors: John
authors: J
authors: Gliatis
authors: Maria
authors: M
authors: Papandreou
authors: George
authors: G
authors: Gioftsos
authors: Jacqueline A
authors: JA
authors: Oldham
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000145:classification* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders; D055815:Young Adult