title: The effect of symptom clusters on functional status and quality of life in women with breast cancer.
abstract: OBJECTIVE
  The purposes of this study of women with breast cancer receiving chemotherapy with/without radiation therapy were to determine whether: (1) subgroups of oncology outpatients can be identified based on a specific symptom cluster (i.e., pain, fatigue, sleep disturbances, depression); (2) these subgroups differ on outcomes (i.e., functional status, quality of life); (3) subgroup membership changes over time.
  
  
  METHODS
  A secondary data analysis using data collected from 112 women at initial chemotherapy. Symptom and outcome measures were completed at three time points: baseline (i.e., the week before cycle two - T1); end of cancer treatment (T2), end of the study (approximately one year after the start of chemotherapy - T3). Cluster analysis identified patient subgroups based on symptom severity scores.
  
  
  RESULTS
  At T1 and T2, four patient subgroups were identified: ALL LOW (one or no symptom greater than the cut score), MILD (two symptoms), MODERATE (three or four symptoms), and ALL HIGH (four symptoms). At T3, three subgroups were identified: MILD, MODERATE and ALL HIGH. Subgroups with high severity levels of all four symptoms had poorer functional status and QOL at each time point than other subgroups (p<0.001). Group membership changed over time.
  
  
  CONCLUSIONS
  Subgroups of patients with different symptom experiences were identified. For some patients severity of all four symptoms persisted months after cancer treatment. Initial and ongoing assessment to identify those patients in the ALL HIGH patient subgroup is important so that appropriate interventions to improve functional status and quality of life can be offered.
authors.affiliation: Department of Physiological Nursing, School of Nursing, University of California, San Francisco, N631, 2 Koret Way, San Francisco, CA 94143-0610, USA. marylin.dodd@nursing.ucsf.edu
authors.forename: Marylin J
authors.initials: MJ
authors.lastname: Dodd
authors.forename: Maria H
authors.initials: MH
authors.lastname: Cho
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Cooper
authors.forename: Christine
authors.initials: C
authors.lastname: Miaskowski
mesh_terms: D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000523:psychology* / Q000532:radiotherapy; D016000:Cluster Analysis; D003863:Depression / Q000209:etiology / Q000523:psychology; D005221:Fatigue / Q000209:etiology / Q000523:psychology; D005260:Female; D006801:Humans; D008875:Middle Aged; D010146:Pain / Q000209:etiology / Q000523:psychology; D010147:Pain Measurement; D011788:Quality of Life; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000209:etiology / Q000523:psychology; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires