Predicting 3-year survival in older people with intellectual disabilities using a Frailty Index

J Am Geriatr Soc. 2015 Mar;63(3):531-6. doi: 10.1111/jgs.13239. Epub 2015 Mar 6.


Objectives: To analyze the relationship between frailty and survival in older people with intellectual disabilities (IDs).

Design: Population-based longitudinal observational study.

Setting: Three Dutch care provider services.

Participants: Individuals with borderline to profound ID aged 50 and older (N=982).

Measurements: A frailty index (FI) including 51 health-related deficits was used to measure frailty. Mean follow-up was 3.3 years. The Cox proportional hazards model was used to evaluate the independent effect of frailty on survival. The discriminative ability of the FI was measured using a receiver operating characteristic (ROC) curve.

Results: Greater FI values were associated with greater risk of death, independent of sex, age, level of ID, and Down syndrome. There was a nonlinear increase in risk with increasing FI value. For example, mortality risk was 2.17 times as great (95% confidence interval (CI)=0.95-4.95) for vulnerable individuals (FI 0.20-0.29) and 19.5 (95% CI=9.13-41.8) times as great for moderately frail individuals (FI 0.40-0.49) as for relatively fit individuals (FI<0.20). The area under the ROC curve for 3-year survival was 0.78.

Conclusion: Although the predictive validity of the FI should be further determined, it was strongly associated with 3-year mortality. Care providers working with people with ID should be able to recognize frail clients and act in an early stage to stop or prevent further decline.

Keywords: frailty; older people with ID; survival.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Frail Elderly
  • Geriatric Assessment*
  • Humans
  • Intellectual Disability / mortality*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Prognosis
  • Survival Rate
  • Time Factors