title: Identification, Associated Factors, and Prognosis of Symptom Clusters in Taiwanese Patients With Heart Failure.
abstract: BACKGROUND
  Patients with heart failure (HF) have multiple distressing symptoms that are associated with poor outcomes. These symptoms do not occur in isolation from each other but likely occur as discrete clusters that may prove helpful to clinicians trying to counsel patients about symptom monitoring and management. Defining common symptom clusters and determining the associations between symptom clusters and outcomes may improve patient management.
  
  
  OBJECTIVE
  The aim of this study was to define symptom clusters and their association with event-free survival in terms of cardiac hospitalization and all-cause mortality in patients with HF.
  
  
  METHODS
  Patients were recruited from outpatient HF clinics. Physical symptoms (dyspnea, fatigue, edema, sleeplessness, anorexia, and poor memory) were measured using the modified Pulmonary Function Status and Dyspnea Questionnaire and the Minnesota Living with Heart Failure Questionnaire. A two-stage cluster analysis was conducted to identify subgroups of patients based on the self-perceived severity of the six symptoms. The Kaplan-Meier survival curve and log-rank test were used to assess whether symptom clusters were associated with event-free survival through a 12-month follow-up.
  
  
  RESULTS
  Two hundred fifty-eight patients (mean age = 61.2 ± 12.3 years, 75% male, 41% New York Heart Association class III/IV) participated. Three symptom clusters were identified based on the severity of symptoms. These clusters were called the nonsevere symptom cluster (all symptoms were rated with low severity), the typical severity symptom cluster (high level of severity for dyspnea and fatigue, low level of severity for edema, and moderate level of severity for all other symptoms), and the atypical severity symptom cluster (low level of severity for dyspnea and fatigue, high level of severity for edema, and moderate level of severity for all other symptoms). Symptom clusters were associated with event-free survival (p < .001). A post hoc comparison showed that the prognosis was better in the nonsevere symptom cluster than both the typical symptom (p < .001) and nontypical symptom (p < .001) clusters and that the prognoses for the latter two clusters did not differ significantly.
  
  
  CONCLUSIONS
  Symptom clusters play an important role in the prognoses of patients with HF. Both patients and healthcare providers may use the information that is provided by this study to improve the surveillance and management of related symptoms.
authors.forename: Tsuey-Yuan
authors.initials: TY
authors.lastname: Huang
authors.affiliation: PhD, RN, FAAN, Professor, College of Nursing, University of Kentucky, Lexington, USA.
authors.forename: Debra K
authors.initials: DK
authors.lastname: Moser
authors.affiliation: DNSc, RN, Chair Professor, Department of Nursing, Asia University, Taichung, Taiwan, ROC.
authors.forename: Shiow-Li
authors.initials: SL
authors.lastname: Hwang
mesh_terms: D000368:Aged; D000855:Anorexia / Q000209:etiology*; D002423:Cause of Death; D016000:Cluster Analysis; D018572:Disease-Free Survival; D004417:Dyspnea / Q000209:etiology*; D004487:Edema / Q000209:etiology*; D005221:Fatigue / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications* / Q000401:mortality / Q000628:therapy; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000209:etiology*; D011795:Surveys and Questionnaires; D013577:Syndrome; D013624:Taiwan / Q000453:epidemiology