title: Frailty index of deficit accumulation and falls: data from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton cohort.
abstract: BACKGROUND
  To investigate the association between frailty index (FI) of deficit accumulation and risk of falls, fractures, death and overnight hospitalizations in women aged 55 years and older.
  
  
  METHODS
  The data were from the Global Longitudinal Study of Osteoporosis in Women (GLOW) Hamilton Cohort. In this 3-year longitudinal, observational cohort study, women (N=3,985) aged ≥ 55 years were enrolled between May 2008 and March 2009 in Hamilton, Canada. A FI including co-morbidities, activities of daily living, symptoms and signs, and healthcare utilization was constructed using 34 health deficits at baseline. Relationship between the FI and falls, fractures, death and overnight hospitalizations was examined.
  
  
  RESULTS
  The FI was significantly associated with age, with a mean rate of deficit accumulation across baseline age of 0.004 or 0.021 (on a log scale) per year. During the third year of follow-up, 1,068 (31.89%) women reported at least one fall. Each increment of 0.01 on the FI was associated with a significantly increased risk of falls during the third year of follow-up (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.02-1.03). The area under the curve (AUC) of the predictive model was 0.69 (95% CI: 0.67-0.71). Results of subgroup and sensitivity analyses indicated the relationship between the FI and risk of falls was robust, while bootstrap analysis judged its internal validation. The FI was significantly related to fractures (hazard ratio [HR]: 1.02, 95% CI: 1.01-1.03), death (OR: 1.05, 95% CI: 1.03-1.06) during the 3-year follow-up period and overnight hospitalizations (incidence rate ratio [IRR]: 1.02, 95% CI: 1.02-1.03) for an increase of 0.01 on the FI during the third year of follow-up. Measured by per standard deviation (SD) increment of the FI, the ORs were 1.21 and 1.40 for falls and death respectively, while the HR was 1.17 for fractures and the IRR was 1.18 for overnight hospitalizations respectively.
  
  
  CONCLUSIONS
  The FI of deficit accumulation increased with chronological age significantly. The FI was associated with and predicted increased risk of falls, fractures, death and overnight hospitalizations significantly.
authors.forename: Guowei
authors.initials: G
authors.lastname: Li
authors.forename: George
authors.initials: G
authors.lastname: Ioannidis
authors.forename: Laura
authors.initials: L
authors.lastname: Pickard
authors.forename: Courtney
authors.initials: C
authors.lastname: Kennedy
authors.forename: Alexandra
authors.initials: A
authors.lastname: Papaioannou
authors.forename: Lehana
authors.initials: L
authors.lastname: Thabane
authors.affiliation: Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4 L8, Canada. jd.adachi@sympatico.ca.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Adachi
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D016330:Frail Elderly / Q000523:psychology; D014943:Global Health / Q000639:trends; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology