title: The identification of empirically derived cancer patient subgroups using psychosocial variables.
abstract: OBJECTIVE
  To determine if there are subgroups of cancer patients who differ on coping, psychological, and quality of life (QOL) measures, and to determine if these subgroups have a different course of distress and health following a cancer diagnosis.
  
  
  METHODS
  Three hundred fifty-one individuals presenting to a multidisciplinary melanoma clinic completed a baseline questionnaire packet containing the Brief Symptom Inventory (BSI), the Medical Outcomes Survey Short-Form 36 (SF-36), Ways of Coping (WOC), State-Trait Anxiety Inventory (STAI), an informed consent form, and a demographic questionnaire. Participants subsequently completed measures at 2, 5, and 9 months after completion of their baseline assessment. A k-means cluster analysis was conducted using the subscales of the STAI, SF-36, and WOC.
  
  
  RESULTS
  Four distinct clusters, psychologically unhealthy, physically unhealthy, combined psychologically and physically unhealthy, and healthy, were identified. These clusters differed on the General Severity Index (GSI) of the BSI and the General Health scale of the SF-36 at each of the four assessment points. The course of distress and general health was distinct for each cluster during the study, with combined and psychologically unhealthy clusters having greater levels of distress and combined and physically unhealthy clusters having poorer overall health.
  
  
  CONCLUSIONS
  The findings from this study provide support for distinct subgroups of patients presenting with a diagnosis of cancer whose level of distress and general health vary greatly following a cancer diagnosis. Clinical interventions tailored to the level of psychological or physical impairment as determined by the cluster may result in better outcomes following cancer treatment.
authors.affiliation: Centers for Behavioral and Preventive Medicine, The Miriam Hospital and Brown Medical School, CORO Building, Suite 500, One Hoppin Street, Providence, RI 02903, USA. peter_trask@brown.edu
authors.forename: Peter C
authors.initials: PC
authors.lastname: Trask
authors.forename: Kent A
authors.initials: KA
authors.lastname: Griffith
mesh_terms: D000223:Adaptation, Psychological; D016000:Cluster Analysis; D003863:Depression / Q000175:diagnosis / Q000209:etiology*; D036262:Empirical Research; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000523:psychology*; D008875:Middle Aged; D011788:Quality of Life; D012720:Severity of Illness Index; D012878:Skin Neoplasms / Q000523:psychology*; D011795:Surveys and Questionnaires