title: Chronic low back pain patient groups in primary care--a cross sectional cluster analysis.
abstract: BACKGROUND
  Due to the heterogeneous nature of chronic low back pain (CLBP), it is necessary to identify patient groups and evaluate treatments within these groups. We aimed to identify groups of patients with CLBP in the primary care setting.
  
  
  METHODS
  We performed a k-means cluster analysis on a large data set (n = 634) of primary care patients with CLBP. Variables of sociodemographic data, pain characteristics, psychological status (i.e., depression, anxiety, somatization), and the patient resources of resilience and coping strategies were included.
  
  
  RESULTS
  We found three clusters that can be characterized as "pensioners with age-associated pain caused by degenerative diseases", "middle-aged patients with high mental distress and poor coping resources", and "middle-aged patients who are less pain-affected and better positioned with regard to their mental health".
  
  
  CONCLUSIONS
  Our results supported current knowledge concerning groups of CLBP patients in primary care. In particular, we identified a group that was most disabled and distressed, and which was mainly characterized by psychological variables. As shown in our study, pain-related coping strategies and resilience were low in these patients and might be addressed in differentiating treatment strategies. Future studies should focus on the identification of this group in order to achieve effective treatment allocation.
  
  
  BACKGROUND
  German Clinical Trial Register DRKS00003123.
authors.affiliation: Department of General Practice / Family Medicine, Philipps University of Marburg, Karl-von-Frisch-Str, 4, 35043 Marburg, Germany. annika.viniol@staff.uni-marburg.de.
authors.forename: Annika
authors.initials: A
authors.lastname: Viniol
authors.forename: Nikita
authors.initials: N
authors.lastname: Jegan
authors.forename: Oliver
authors.initials: O
authors.lastname: Hirsch
authors.forename: Corinna
authors.initials: C
authors.lastname: Leonhardt
authors.forename: Markus
authors.initials: M
authors.lastname: Brugger
authors.forename: Konstantin
authors.initials: K
authors.lastname: Strauch
authors.forename: Jürgen
authors.initials: J
authors.lastname: Barth
authors.forename: Erika
authors.initials: E
authors.lastname: Baum
authors.forename: Annette
authors.initials: A
authors.lastname: Becker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D006801:Humans; D017116:Low Back Pain / Q000453:epidemiology* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care / Q000706:statistics & numerical data*; D055815:Young Adult