title: The relationship of multimorbidity with disability and frailty in the oldest patients: a cross-sectional analysis of three measures of multimorbidity in the BELFRAIL cohort.
abstract: BACKGROUND
  Ageing people show increasing morbidity, dependence and vulnerability.
  
  
  OBJECTIVE
  To compare the relationships of different measures of multimorbidity with dependence (operationalized as disability) and vulnerability (operationalized as frailty).
  
  
  METHODS
  A cross-sectional analysis within the BELFRAIL cohort (567 subjects aged ≥ 80). Multimorbidity was measured using a disease count (DC), the Charlson comorbidity index (CCI) and the cumulative illness rating scale (CIRS), respectively. Associations with disability (based on activities of daily living) and frailty (defined by the Fried frailty criteria) were assessed using bivariable and multivariable analyses. Net reclassification improvement (NRI) values were calculated to compare the abilities of the DC, CCI and CIRS to identify patients with disability or frailty.
  
  
  RESULTS
  Disability was associated with the DC (crude odds ratio, OR: 2.1; 95% confidence interval, CI: 1.4-3.4), CCI (crude OR: 1.8; 95% CI: 1.2-2.7) and CIRS (crude OR: 4.0; 95% CI: 2.5-6.5); only the association with CIRS was independent of age, sex, chronic inflammation, impaired cognition and frailty (adjusted OR: 3.2; 95% CI: 1.7-5.8). Frailty was associated with CCI (crude OR: 2.4; 95% CI: 1.2-4.6) and CIRS (crude OR: 2.6; 95% CI: 1.3-5.3); adjusted for age, sex, chronic inflammation, impaired cognition and disability. These associations were not statistically significant. The NRIs demonstrated a similar ability of the DC, CCI, and CIRS to identify patients with disability or frailty, respectively.
  
  
  CONCLUSIONS
  The associations of different measures of multimorbidity with disability and frailty differ but their ability to identify patients with disability or frailty is similar. Generally, multimorbidity scores incompletely reflect dependence and vulnerability in this age group.
authors: Department of Family Medicine and Primary Health Care, Ghent University (UG) , Belgium.
authors: Pauline
authors: P
authors: Boeckxstaens
authors: Bert
authors: B
authors: Vaes
authors: Delphine
authors: D
authors: Legrand
authors: Olivia
authors: O
authors: Dalleur
authors: An
authors: A
authors: De Sutter
authors: Jean-Marie
authors: JM
authors: Degryse
mesh_terms: D000203:Activities of Daily Living; D000369:Aged, 80 and over; D001530:Belgium; D002908:Chronic Disease; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D006801:Humans; D008297:Male; D011446:Prospective Studies
keywords: Multimorbidity; disability; frailty