Derivation and validation of a mortality-risk index from a cohort of frail elderly patients hospitalised in medical wards via emergencies: the SAFES study
- 349 Downloads
To identify predictive factors for 2-year mortality in frail elderly patients after acute hospitalisation, and from these to derive and validate a Mortality Risk Index (MRI). A prospective cohort of elderly patients was set up in nine teaching hospitals. This cohort was randomly split up into a derivation cohort (DC) of 870 subjects and a validation cohort (VC) of 436 subjects. Data obtained from a Comprehensive Geriatric Assessment were used in a Cox model to predict 2-year mortality and to identify risk groups for mortality. A ROC analysis was performed to explore the validity of the MRI. Five factors were identified and weighted using hazard ratios to construct the MRI: age 85 or over (1 point), dependence for the ADL (1 point), delirium (2 points), malnutrition risk (2 points), and co-morbidity level (2 points for medium level, 3 points for high level). Three risk groups were identified according to the MRI. Mortality rates increased significantly across risk groups in both cohorts. In the DC, mortality rates were: 20.8% in the low-risk group, 49.6% in the medium-risk group, and 62.1% in the high-risk group. In the VC, mortality rates were respectively 21.7, 48.5, and 65.4%. The area under the ROC curve for overall score was statistically the same in the DC (0.72) as in the VC (0.71). The proposed MRI appears as a simple and easy-to-use tool developed from relevant geriatric variables. Its accuracy is good and the validation procedure gives a good stability of results.
KeywordsMortality Survival Risk score Prediction Validation SAFES cohort
To sources of funding: The French Ministry of Health, funding the Clinical Research Hospital Projects (PHRC 1998); The National Health Insurance Agency for Wage Earners–CNAMTS, France; The Institute of Longevity and Ageing–INSERM, France. To Angela Swaine Verdier for her help with the English draft.
Conflicts of interest declaration
The authors each declare no conflict of interest. The financial sponsors played no role in the design, execution, analysis and interpretation of data, or in writing the manuscript.
- 1.Lang PO, Heitz D, Hedelin G, Drame M, Jovenin N, Ankri J, et al. Early markers of prolonged hospital stays in older people: a prospective, multicenter study of 908 inpatients in French acute hospitals. J Am Geriatr Soc. 2006;54:1031–9. doi: 10.1111/j.1532-5415.2006.00767.x.PubMedCrossRefGoogle Scholar
- 6.Palmer RM. Acute care. In: Hazzard WR, Blass JP, Ettinger WH, Halter JB, Ouslander JG, editors. Principles of geriatric medicine and gerontology. New York: McGraw-Hill; 1999. p. 483–487.Google Scholar
- 7.Zuliani G, Romagnoni F, Soattin L, Leoci V, Volpato S, Fellin R. Predictors of two-year mortality in older nursing home residents. The IRA study. Istituto di riposo per anziani. Aging (Milano). 2001;13:3–7.Google Scholar
- 9.Covinsky KE, Palmer RM, Fortinsky RH, Counsell SR, Stewart AL, Kresevic D, et al. Loss of independence in activities of daily living in older adults hospitalized with medical illnesses: increased vulnerability with age. J Am Geriatr Soc. 2003;51:451–8. doi: 10.1046/j.1532-5415.2003.51152.x.PubMedCrossRefGoogle Scholar
- 11.American Psychiatry Association. DSM IV, diagnostic and statistical manual mental disorders. 4th ed. Washington: American Psychiatric Association; 1994.Google Scholar
- 15.Norton D, Mclaren R, Exton-Smith A. An investigation of nursing problems in hospitals. New-York: Churchill Livingstone; 1975.Google Scholar
- 19.Green DM, Swets JA. Signal detection theory and psychophysics. New-York: Wiley; 1966.Google Scholar
- 20.Swets JA, Pickett RM. Evaluation of diagnostic systems: methods from signal detection theory. New-York: Academic Press; 1982.Google Scholar
- 27.Incalzi RA, Capparella O, Gemma A, Landi F, Bruno E, Di Meo F, et al. The interaction between age and comorbidity contributes to predicting the mortality of geriatric patients in the acute-care hospital. J Intern Med. 1997;242:291–8. doi: 10.1046/j.1365-2796.1997.00132.x.PubMedCrossRefGoogle Scholar
- 28.Inouye SK, Bogardus ST Jr, Vitagliano G, Desai MM, Williams CS, Grady JN, et al. Burden of illness score for elderly persons: risk adjustment incorporating the cumulative impact of diseases, physiologic abnormalities, and functional impairments. Med Care. 2003;41:70–83. doi: 10.1097/00005650-200301000-00010.PubMedCrossRefGoogle Scholar