Open AccessDevelopment and Validation of a Functional Morbidity Index to Predict Mortality in Community‐dwelling Elders
Author(s) -
Carey Elise C.,
Walter Louise C.,
Lindquist Karla,
Covinsky Kenneth E.
Publication year - 2004
Publication title -
journal of general internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.746
H-Index - 180
eISSN - 1525-1497
pISSN - 0884-8734
DOI - 10.1111/j.1525-1497.2004.40016.x
Subject(s) - medicine , cohort , gerontology , demography , activities of daily living , logistic regression , cohort study , population , physical therapy , environmental health , sociology
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 ≥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.