Aging Clinical and Experimental Research

, Volume 17, Issue 6, pp 465–471 | Cite as

Evaluation of a frailty index based on a comprehensive geriatric assessment in a population based study of elderly Canadians

  • David Jones
  • Xiaowei Song
  • Arnold Mitnitski
  • Kenneth Rockwood
Original Articles


Background and aims: Objectives were to develop a frailty index (FI) based on a standard comprehensive geriatric assessment (CGA) derived from a clinical examination; to assess the validity of the FI-CGA and to compare its precision with other frailty measures. Methods: Design: Secondary analysis of a prospective cohort study, with five-year follow-up data. Setting: Second phase of the Canadian Study of Health and Aging (CSHA-2); clinical examinations were performed in clinics, nursing homes, and patients’ homes. Participants: People selected (as either cognitively impaired cases or unimpaired controls) to receive the CSHA-2 clinical examination (n=2305; women=1431). Measurements: Clinical and performance-based measures and diagnostic data were extracted to correspond to the 10 impairment domains and the single comorbidity domain of a CGA. The proportion of deficits accumulated in each domain was calculated to yield the FI-CGA. The FI-CGA was validated and its predictive ability compared with other frailty measures. Results: Within the seven grades of fitness/frailty identified, subjects with greater frailty were older, less educated, and more likely to be women. The FI-CGA correlated highly with a previously validated, empirically-derived frailty index (r=0.76). Frailty was associated with higher risk of death (for each increment in frailty, the hazard ratio, adjusted for age, sex and education, was 1.23 (95% CI 1.18–1.29) and institutionalization (HR 1.20; 1.10–1.32). Conclusions: In a population survey, the FI-CGA is a valid means of quantifying frailty from routinely collected data.


Comprehensive geriatric assessment frailty frailty index 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Hogan DB, MacKnight C, Bergman H. Models, definitions, and criteria of frailty. Aging Clin Exp Res 2003; 15: 1–29.PubMedCrossRefGoogle Scholar
  2. 2.
    Vanitallie TB. Frailty in the elderly: Contributions of sarcopenia and visceral protein depletion. Metabolism 2003; 52: 22–6.PubMedCrossRefGoogle Scholar
  3. 3.
    Rockwood K, Mitnitski A, Macknight C. Some mathematical models of frailty and their clinical implications. Rev Clin Gerontol 2002; 12: 109–17.CrossRefGoogle Scholar
  4. 4.
    Rockwood K, Stadnyk K, MacKnight C, McDowell I, Hebert R, Hogan DB. A brief clinical instrument to classify frailty in elderly people. Lancet 1999; 353: 205–6.PubMedCrossRefGoogle Scholar
  5. 5.
    Morley JE, Perry HM 3rd, Miller DK. Editorial: Something about frailty. J Gerontol 2002; 57: M698–704CrossRefGoogle Scholar
  6. 6.
    Ferrucci L, Guralnik JM, Cavazzini C, et al. The frailty syndrome: a critical issue in geriatric oncology. Crit Rev Oncol Hematol 2003; 46: 127–37.PubMedCrossRefGoogle Scholar
  7. 7.
    Fried LP, Tangen CM, Walston J, et al. Frailty in older adults: evidence for a phenotype. J Gerontol 2001; 56: M146–56.CrossRefGoogle Scholar
  8. 8.
    Brown M, Sinacore DR, Binder EF, Kohrt WH. Physical and performance measures for the identification of mild to moderate frailty. J Gerontol 2000; 55: M350–5.CrossRefGoogle Scholar
  9. 9.
    Mitnitksi AB, Song X, Rockwood K. The estimation of relative fitness and frailty in community dwelling older adults using self-report data. J Gerontol 2004; 59: M627–32.CrossRefGoogle Scholar
  10. 10.
    Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K. Frailty, fitness and late-life mortality in relation to chronological and biological age. BMC Geriatrics 2002; 2: 1–8.PubMedCrossRefGoogle Scholar
  11. 11.
    Mitnitski AB, Mogilner AJ, MacKnight C, Rockwood K. The mortality rate as a function of accumulated deficits in a frailty index. Mech Ageing Dev 2002; 123: 1457–60.PubMedCrossRefGoogle Scholar
  12. 12.
    Mitnitski AB, Mogilner AJ, MacKnight C, Rockwood K. The accumulation of deficits with age and possible invariants of aging. Scientific World Journal 2002; 2: 1816–22.PubMedCrossRefGoogle Scholar
  13. 13.
    Gavrilov LA, Gavrilova NS. The reliability theory of aging and longevity. J Theor Biol 2001; 213: 527–45.PubMedCrossRefGoogle Scholar
  14. 14.
    Kirkwood TB, Proctor CJ. Somatic mutations and ageing in silica Mech Ageing Dev 2003; 124: 85–92.PubMedCrossRefGoogle Scholar
  15. 15.
    Song X, Mitnitski AB, MacKnight C, Rockwood K. Assessment of individual risk of dealth using self report data: an artificial neural network compared to a frailty index. J Am Geriatr Soc 2004; 52: 1180–84.PubMedCrossRefGoogle Scholar
  16. 16.
    Rockwood K, Silvius JL, Fox RA. Comprehensive geriatric assessment. Postgrad Med 1998; 103: 247–64.PubMedCrossRefGoogle Scholar
  17. 17.
    Jones DM, Song X, Rockwood K. Operationizing a frailty index from a standardized comprehensive geriatric assessment. J Am Geriatr Soc 2004; 52: 1929–33.PubMedCrossRefGoogle Scholar
  18. 18.
    Rockwood K, Wolfson C, McDowell I. The Canadian Study of Health and Aging. Int Psychogeriatr 2001; 13(Suppl 1): 1–237.Google Scholar
  19. 19.
    Graham JE, Rockwood K, Beattie BL, McDowell I, Eastwood R, Gauthier S. Standardization of the diagnosis of dementia in the Canadian Study of Health and Aging. Neuroepidemiology 1996; 15: 246–56.PubMedCrossRefGoogle Scholar
  20. 20.
    Teng EL, Chui HC. The Modified Mini-Mental State (3MS) examination. J Clin Psychiatry 1987; 48: 314–18.PubMedGoogle Scholar
  21. 21.
    Rockwood K, Mogilner A, Mitnitski A. Changes with age in the distribution of a frailty index. Mech Ageing Dev 2004; 125: 7–19.CrossRefGoogle Scholar
  22. 22.
    Conwell Y, Forber NT, Cox C, Caine DE. Validation of a measure of physical illness burden at autopsy: the Cumulative Illness Rating Scale. J Am Geriatr Soc 1993; 41: 38–41.PubMedGoogle Scholar
  23. 23.
    Rockwood K, Fox RA, Stolee P, Robertson D, Beattie BL. Frailty in elderly people: an evolving concept. CMAJ 1994; 150: 489–95.PubMedGoogle Scholar
  24. 24.
    Miles TP, Palmer RF, Espino DV, Mouton CP, Lichtenstein MJ, Markides KS. New-onset incontinence and markers of frailty: data from the Hispanic Established Populations for Epidemiologic Studies of the Elderly. J Gerontol 2001; 56: M19–24.CrossRefGoogle Scholar
  25. 25.
    Dubois MF, Hebert R. Imputation of missing dates of death or institutionalization for time-to-event analyses in the Canadian Study of Health and Aging. Int Psychogeriatr 2001; 13(Suppl 1): 91–7.PubMedCrossRefGoogle Scholar
  26. 26.
    Thomas VS, Rockwood K, McDowell I. Multidimensionality in instrumental and basic activities of daily living. J Clin Epidemiol 1998; 51: 315–21.PubMedCrossRefGoogle Scholar
  27. 27.
    MacKnight C, Rockwood K. Use of the chronic disease score to measure comorbidity in the Canadian Study of Health and Aging. Int Psychogeriatr 2001; 13(Suppl 1): 137–42.PubMedCrossRefGoogle Scholar
  28. 28.
    Vapnik V. The Nature of Statistical Learning Theory. Springer, 1995.Google Scholar
  29. 29.
    Walston J. Frailty- the search for underlying causes. Sci Aging Knowledge Environ 2004; 4: PE4.Google Scholar
  30. 30.
    Schalk BW, Visser M, Deeg DJ, Bouter LM. Lower levels of serum albumin and total cholesterol and future decline in functional performance in older persons: the Longitudinal Aging Study Amsterdam. Age Ageing 2004; 33: 266–272.PubMedCrossRefGoogle Scholar
  31. 31.
    Chin A Paw MJ, de Groot LC, van Gend SV, et al. Inactivity and weight loss: effective criteria to identify frailty. J Nutr Health Aging 2003; 7: 55–60.Google Scholar
  32. 32.
    Rockwood K, Howlett SE, MacKnight C, et al. Prevalence, attributes and outcomes of fitness and frailty in community-dwelling older adults: report from the Canadian Study of Health and Aging. J Gerontol 2004; 59: 1310–7.CrossRefGoogle Scholar
  33. 33.
    Katz IR. Depression and frailty: the need for multidisciplinary research. Am J Geriatr Psychiatry 2004; 12: 1–6.PubMedGoogle Scholar

Copyright information

© Springer Internal Publishing Switzerland 2005

Authors and Affiliations

  • David Jones
    • 1
  • Xiaowei Song
    • 2
  • Arnold Mitnitski
    • 3
    • 4
  • Kenneth Rockwood
    • 2
    • 3
  1. 1.Faculty of MedicineMemorial UniversitySt. John’s
  2. 2.Geriatric Medicine Research UnitQE II Health Sciences CenterHalifax
  3. 3.Department of MedicineDalhousie UniversityHalifax
  4. 4.Faculty of Computer ScienceDalhousie UniversityHalifaxCanada

Personalised recommendations