title: Depressive symptoms in heart failure: Independent prognostic factor or marker of functional status?
abstract: OBJECTIVE
  The prognostic potential of depressive symptoms independent of somatic features of heart failure severity has repeatedly been demonstrated. However, patient-reported functional status has rarely been accounted for in these studies. Thus, it has remained unclear to what extent the predictive power of depressive symptoms may mirror functional status. We therefore aimed to evaluate the prognostic value of depressive symptoms adjusting for patient-reported functional status in a large, well-characterized sample of patients with systolic heart failure.
  
  
  METHODS
  Eight hundred sixty-three patients, 67±12 years old, 72% men, and 42% with New York Heart Association functional classes III/IV, who participated in the extended Interdisciplinary Network Heart Failure (INH) study were investigated. We assessed depressive symptoms using the Patient Health Questionnaire (PHQ-9) and patient-reported functional status with the Kansas City Cardiomyopathy Questionnaire (KCCQ). Data on survival was obtained after a follow-up of 18 months (100% complete).
  
  
  RESULTS
  Depressive symptoms predicted mortality risk (HR per PHQ-9 scale point=1.07, 95% CI 1.04-1.09, p<.001), even after adjustment for heart failure severity and co-morbidities (HR=1.04, 95% CI 1.01-1.07, p=.017). However, they were no longer significant predictors (HR=1.01, 95% CI 0.98-1.05, p=0.46) after additional adjustment for patient-reported functional status, which proved predictive of mortality risk (HR=0.90, 95% CI 0.82-0.99, p=.025).
  
  
  CONCLUSIONS
  Our results suggest that the association of depressive symptoms with functional status may at least partly explain the prognostic potential of depressive symptoms.
authors.affiliation: University of Würzburg, Department of Medical Psychology, Medical Sociology, and Rehabilitation Sciences, Würzburg, Germany. Electronic address: h.faller@uni-wuerzburg.de.
authors.forename: Hermann
authors.initials: H
authors.lastname: Faller
authors.affiliation: University of Würzburg, Department of Internal Medicine I, Würzburg, Germany; Comprehensive Heart Failure Center, Würzburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Störk
authors.affiliation: University of Würzburg, Institute of Clinical Epidemiology and Biometry, Würzburg, Germany; Center for Clinical Studies Würzburg, Würzburg, Germany.
authors.forename: Götz
authors.initials: G
authors.lastname: Gelbrich
authors.affiliation: University of Würzburg, Department of Medical Psychology, Medical Sociology, and Rehabilitation Sciences, Würzburg, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Schowalter
authors.affiliation: University of Würzburg, Department of Internal Medicine I, Würzburg, Germany; Comprehensive Heart Failure Center, Würzburg, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Ertl
authors.affiliation: University of Würzburg, Department of Internal Medicine I, Würzburg, Germany; Comprehensive Heart Failure Center, Würzburg, Germany.
authors.forename: Christiane E
authors.initials: CE
authors.lastname: Angermann
mesh_terms: D000368:Aged; D002986:Clinical Trials as Topic; D015897:Comorbidity; D003863:Depression / Q000150:complications* / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011594:Psychometrics; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016019:Survival Analysis
keywords: Depression; Functional status; Heart failure; Kansas City Cardiomyopathy Questionnaire; Mortality; Patient Health Questionnaire