title: Sex differences in the construct overlap of frailty and depression: evidence from the Health and Retirement Study.
abstract: OBJECTIVE
  To determine the degree of diagnostic overlap between frailty and depression and to investigate whether sex differences in symptom endorsement influence this overlap.
  
  
  METHODS
  Cross-sectional latent class analysis.
  
  
  METHODS
  Data were from the 2008 wave of the Health and Retirement Study, a nationally representative longitudinal survey of health characteristics of older adults.
  
  
  METHODS
  Community-dwelling adults aged 65 and older completing a general health questionnaire and consenting to physical measurements (N = 3,665).
  
  
  METHODS
  Frailty was measured using criteria developed in the Cardiovascular Health Study, and depressive symptoms were measured using the eight-item Center for Epidemiologic Studies Depression scale.
  
  
  RESULTS
  Frailty and depression were best modeled as two distinct but highly correlated constructs with three and four classes of symptom response, respectively. Measurement overlap was high in men and women. Approximately 73% of individuals with severe depressive symptoms and 86% with primarily somatic depressive symptoms were categorized as concurrently frail. The degree of construct overlap between depression and frailty did not significantly vary according to sex, but women were significantly more likely to endorse all frailty and depressive symptoms.
  
  
  CONCLUSIONS
  Measures of depression and frailty identify substantially overlapping populations of older men and women. More-frequent endorsement of depressive symptoms, but not differential endorsement of somatic symptoms, may contribute to the higher prevalence of frailty in women. The symptom of exhaustion is particularly important to the correlation between these two conditions. Findings will inform clinician and researcher efforts to refine the definition of geriatric syndromes such as frailty and to develop effective interventions.
authors.affiliation: Division of Epidemiology, Department of Family Medicine and Population Health, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Lohman
authors.forename: Levent
authors.initials: L
authors.lastname: Dumenci
authors.forename: Briana
authors.initials: B
authors.lastname: Mezuk
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data; D015577:Geriatric Assessment / Q000379:methods*; D006304:Health Status; D006306:Health Surveys / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012179:Retirement / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D017678:Sex Distribution; D012737:Sex Factors; D014481:United States / Q000453:epidemiology
keywords: depression; frailty; latent class; sex