The Predictive Validity of Self-Report and Performance-based Measures of Function and Health

Abstract

To learn about the value of self-report and performance-based measures of function in predicting mortality and institutionalization, we conducted a longitudinal study of 149 elderly persons at four sites (a senior citizens housing unit, two ambulatory-based geriatrics practices, and a board-and-care facility). At baseline, all subjects were administered a questionnaire containing Katz, Spector, and Rosow-Breslau scale items as well as the Mini-Mental State Exam and two performance-based measures, the Tinetti gait score and Physical Performance Test. At follow-up (average 22 months; range 17-29 months), 17 subjects (11%) had died and seven (5%) had been institutionalized. Univariate analysis demonstrated significant associations between death and all functional status measures. In logistic regression models, Katz items, Tinetti gait score, and the seven-item Physical Performance Test were independent predictors of "death or nursing home placement"; Katz items and the seven-item Physical Performance Test were independent predictors of mortality. These findings support the use of performance-based as well as self-report measures for clinical and research purposes.