Development and validation of a functional morbidity index to predict mortality in community-dwelling elders

J Gen Intern Med. 2004 Oct;19(10):1027-33. doi: 10.1111/j.1525-1497.2004.40016.x.


Objective: Functional measures have a great appeal for prognostic instruments because they are associated with mortality, they represent the end-impact of disease on the patient, and information about them can be obtained directly from the patient. However, there are no prognostic indices that have been developed for community-dwelling elders based primarily on functional measures. Our objective in this study was to develop and validate a prognostic index for 2-year mortality in community-dwelling elders, based on self-reported functional status, age, and gender.

Design: Population-based cohort study from 1993 to 1995.

Setting: Community-dwelling elders within the United States.

Participants: Subjects, age > or =70 (N = 7,393), from the Asset and Health Dynamics Among the Oldest Old study. We developed the index in 4,516 participants (mean age 78, 84% white, 61% female), and validated it in 2,877 different participants (mean age 78, 73% white, 61% female).

Main outcome measures: Prediction of 2-year mortality using risk factors such as activities of daily living, instrumental activities of daily living, additional measures of physical function, age, and gender.

Results: Overall mortality was 10% in the development cohort and 12% in the validation cohort. In the development cohort, 6 independent predictors of mortality were identified and weighted, using logistic regression models, to create a point scale: male gender, 2 points; age (76 to 80, 1 point; >80, 2 points); dependence in bathing, 1 point; dependence in shopping, 2 points; difficulty walking several blocks, 2 points; and difficulty pulling or pushing heavy objects, 1 point. We calculated risk scores for each patient by adding the points of each independent risk factor present. In the development cohort, 2-year mortality was 3% in the lowest risk group (0 to 2 points), 11% in the middle risk group (3 to 6 points), and 34% in the highest risk group (>7 points). In the validation cohort, 2-year mortality was 5% in the lowest risk group, 12% in the middle risk group, and 36% in the highest risk group. The c-statistics for the point system were 0.76 and 0.74 in the development and validation cohorts, respectively.

Conclusions: This prognostic index, which relies solely on self-reported functional status, age, and gender, provides a simple and accurate method of stratifying community-dwelling elders into groups at varying risk of mortality.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Activities of Daily Living*
  • Age Factors
  • Aged / physiology*
  • Female
  • Geriatric Assessment*
  • Health Status Indicators*
  • Humans
  • Male
  • Mortality*
  • Prognosis
  • Reproducibility of Results
  • Residence Characteristics
  • Sex Factors