A comparison and cross-validation of models to predict basic activity of daily living dependency in older adults

Daniel O. Clark, Timothy E. Stump, Wanzhu Tu, Douglas K. Miller

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Background: A simple method of identifying elders at high risk for activity of daily living (ADL) dependence could facilitate essential research and implementation of cost-effective clinical care programs. Objective: We used a nationally representative sample of 9446 older adults free from ADL dependence in 2006 to develop simple models for predicting ADL dependence at 2008 follow-up and to compare the models to the most predictive published model. Candidate predictor variables were those of published models that could be obtained from interview or medical record data. Methods: Variable selection was performed using logistic regression with backward elimination in a two-third random sample (n=6233) and validated in a one-third random sample (n=3213). Model fit was determined using the c-statistic and evaluated vis-a-vis our replication of a published model. Results: At 2-year follow-up, 8.0% and 7.3% of initially independent persons were ADL dependent in the development and validation samples, respectively. The best fitting, simple model consisted of age and number of hospitalizations in past 2 years, plus diagnoses of diabetes, chronic lung disease, congestive heart failure, stroke, and arthritis. This model had a c-statistic of 0.74 in the validation sample. A model of just age and number of hospitalizations achieved a c-statistic of 0.71. These compared with a c-statistic of 0.79 for the published model. Sensitivity analyses demonstrated model robustness. Conclusions: Models based on a widely available data achieve very good validity for predicting ADL dependence. Future work will assess the validity of these models using medical record data.

Original languageEnglish (US)
Pages (from-to)534-539
Number of pages6
JournalMedical care
Volume50
Issue number6
DOIs
StatePublished - Jun 1 2012

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Keywords

  • Activities of daily living
  • Models of care
  • Older adults

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health

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