Table 2.

Associations of objective sleep characteristics with the risk of incident osteoporosis.

Characteristic	HR	95% CI	P
Model 1
Average sleep duration	0.93	0.89-0.98	0.005
Sleep efficiency	0.92	0.88-0.97	<0.001
Sleep regularity index	0.97	0.93-1.02	0.302
Sleep midpoint	1.02	0.97-1.07	0.360
Relative amplitude	0.85	0.81-0.88	<0.001
Model 2
Average sleep duration	0.90	0.86-0.95	<0.001
Sleep efficiency	0.91	0.87-0.96	<0.001
Sleep regularity index	0.93	0.88-0.98	0.004
Sleep midpoint	1.05	1.00-1.11	0.036
Relative amplitude	0.77	0.74-0.81	<0.001
Model 3
Average sleep duration	0.91	0.87-0.95	<0.001
Sleep efficiency	0.92	0.88-0.97	0.001
Sleep regularity index	0.98	0.93-1.03	0.362
Sleep midpoint	1.03	0.98-1.08	0.281
Relative amplitude	0.80	0.76-0.85	<0.001

HR, Hazard Ratio; CI, Confidence Interval.