Table 4. Cox Regression Analysis Predicting Survival of 17,930 Adults, Health and Retirement Study, 2006, 2008, and 2010.

Factor	Hazard Ratioa (95% CI)	P Value
Age	1.08 (1.07–1.09)	<.001
Education	0.99 (0.97–1.01)	.22
Self-rated health	0.28 (0.07–1.14)	.08
Delayed word recall	0.87 (0.85–0.90)	<.001
Depression	1.10 (1.07–1.13)	<.001
Sleep	0.96 (0.89–1.04)	.35
Mild activities	0.70 (0.32–1.56)	.39
Smoking	1.63 (1.41–1.89)	<.001
Body mass index	0.98 (0.97–0.99)	.001

Abbreviation: CI, confidence interval.

^a Estimated with Cox proportional hazards regression while adjusting for other factors in the model.