Table 2.

Unadjusted linear regression models of individual-level cortisol effect regressed on sleep measures for the National Sleep Life, Health and Aging (NSHAP) project Wave 2 from August 2010 to May 2011^a.

Variableb	β	p	95% CI
Actigraph-measured sleep
Average sleep fragmentation, %	0.02	.002	0.01 to 0.03
Average WASO, hours	0.26	.004	0.09 to 0.43
Average sleep duration, hours	0.01	.8	−0.05 to 0.07
Self-reported sleep
Average sleep duration, hours	−0.02	.9	−0.03 to 0.03
Troubled sleep scalec	0.04	.07	−0.00 to 0.09

Abbreviations: CI, confidence interval; WASO, wake after sleep onset.

^a N = 672.

^bEach variable is a separate model.

^cTroubled sleep scale is a combined metric (0 = never/rarely, 1 = sometimes, 2 = most of the time) including trouble falling asleep, trouble waking during the night, and trouble waking too early. Scores may range from 0 to 8, and the β estimates the effect of a 1-unit change in the score.