Table 3.

Predictive Accuracy for 5- and 10-Year Survival by Individual Study and Pooled Data Presented as Area Under the Receiver Operating Characteristic Curves

Outcome and Predictors	C Statistic (95% Confidence Interval)
	CHS8	EPESE15	Health, ABC16,17	Hispanic EPESE8	Invecciare in Chianti18	Osteoporotic Fractures in Men19	NHANES III20	PEP21	Study of Osteoporotic Fractures22	Pooled
5-Year Mortality
Age, sex	0.705 (0.685–0.725)	0.685 (0.658–0.712)	0.606 (0.575–0.637)	0.694 (0.662–0.725)	0.797 (0.754–0.841)	0.700 (0.677–0.723)	0.710 (0.691–0.729)	0.674 (0.616–0.732)	0.646 (0.625–0.667)	0.690 (0.662–0.717)
Age, sex, diseases	0.711 (0.692–0.731)	0.692 (0.665–0.719)	0.616 (0.586–0.647)	0.703 (0.671–0.725)	0.793 (0.747–0.838)	0.704 (0.681–0.727)	0.719 (0.700–0.737)	0.694 (0.737–0.750)	0.662 (0.639–0.684)	0.698 (0.673–0.723)
Age, sex, diseases, BMI, systolic BP, prior hospitalization	0.736 (0.717–0.755)b,c	0.702 (0.676–0.728)	0.650 (0.620–0.680)b,c	0.728 (0.698–0.755)b,c	0.808 (0.765–0.850)	0.728 (0.706–0.749)b	0.744 (0.727–0.762)b,c	0.728 (0.674–0.781)b,c	0.665 (0.643–0.686)	0.719 (0.693–0.745)b
Age, sex, use of mobility aid, functional statusa	NA	NA	NA	0.735 (0.705–0.765)	0.803 (0.756–0.851)	NA	0.738 (0.720–0.757)	0.720 (0.663–0.776)	NA	0.747 (0.720–0.774)
Age, sex, gait speed	0.734 (0.716–0.753)c	0.711 (0.685–0.737)c	0.642 (0.612–0.673)b,c	0.710 (0.679–0.741)	0.803 (0.760–0.846)	0.729 (0.707–0.751)b,c	0.737 (0.719–0.755)b	0.718 (0.664–0.771)c	0.682 (0.662–0.703)b,c	0.717 (0.694–0.740) 0.741 (0.706–0.775)d
10-Year Mortality
Age, sex	0.721 (0.707–0.734)	0.725 (0.704–0.746)	NA	0.700 (0.677–0.724)	NA	NA	0.741 (0.726–0.757)	0.674 (0.627–0.721)	0.689 (0.676–0.703)	0.712 (0.692–0.731)
Age, sex, diseases	0.728 (0.715–0.742)	0.738 (0.716–0.759)	NA	0.709 (0.685–0.733)	NA	NA	0.749 (0.734–0.764)	0.698 (0.652–0.744)	0.706 (0.692–0.719)	0.724 (0.707–0.740)
Age, sex, diseases, BMI, systolic BP, prior hospitalization	0.745 (0.732–0.759)	0.749 (0.729–0.770)	NA	0.733 (0.710–0.756)b	NA	NA	0.768 (0.754–0.783)b	0.723 (0.678–0.727)b,c	0.709 (0.696–0.722)	0.739 (0.719–0.759)b
Age, sex, functional status, walking aid usea	NA	NA	NA	0.722 (0.699–0.746)	NA	NA	0.761 (0.746–0.776)	0.702 (0.655–0.748)	NA	0.732 (0.698–0.767)
Age, sex, gait speed	0.740 (0.727–0.754)	0.753 (0.733–0.774)b	NA	0.709 (0.685–0.732)	NA	NA	0.766 (0.751–0.780)b	0.723 (0.679–0.768)b,c	0.719 (0.706–0.731)b	0.737 (0.718–0.755)b,c 0.734 (0.692–0.777)d

Abbreviations: ABC, Aging and Body Composition; BMI, body mass index, calculated as weight in kilograms divided by height in meters squared; BP, blood pressure; CHS, Cardiovascular Health Study; CI, confidence interval; EPESE, Established Populations for the Epidemiological Study of the Elderly; NA, not applicable; NHANES III, Third National Health and Nutrition Examination Survey; PEP, Predicting Elderly Performance.

^aFunctional status was operationally defined for 3 levels: (1) activities of daily living (ADLs) dependence is defined as report of needing help from another person or being unable to perform any of 6 basic ADLs, 2) Instrumental ADL difficulty is defined as report of no ADL dependence but difficulty performing shopping, meal preparation, or heavy housework, and (3) Independent is defined as no report of ADL dependence or instrumental ADL difficulty.

^bValue is the pooled estimate of the area under the receiver operator characteristic curve for age, sex, and gait speed for the studies that were used in the comparisons of gait speed with use of mobility aids and functional status. Four studies were included in the estimates of 5 y mortality and three in the estimates of 10 y mortality. Values are reported as the C statistic representing area under the receiver operator characteristic curve; values that differ by 0.025 or more are considered substantially different.³⁷

^cC statistic is greater than for age and sex alone.

^dC statistic is greater than for age, sex, and diseases.