Table 3.

Follow-Up Poor Sleep Burden, Sleep Burden Trajectory, and Risk for Delirium

	N (%)	HR (95% CI)	p
Poor sleep burden
Sleep score*	42 105 (100%)	1.12 (1.03–1.22)	.01
Minimal	15 345 (36.5%)	REF	REF
Mild	20 063 (47.7%)	1.28 (0.90–1.76)	.17
Moderate/severe	6 695 (15.9%)	1.61 (1.12–2.23)	.01
Sleep burden trajectory
Improved (score change −1 or more)	10 000 (23.8%)	0.83 (0.59–1.16)	.28
No change (0)	16 652 (39.6%)	REF	REF
Mild worsening (+1)	10 105 (24.0%)	1.06 (0.73–1.52)	.76
Significant worsening (+2 or more)	5 348 (12.7%)	1.79 (1.23–2.62)	.002

Notes: HR = hazard ratio; CI = confidence interval; REF = reference group. Cox proportional hazards models: results presented as hazard ratio (95% confidence interval) and p value. Our poor sleep burden model used our aggregate sleep score as a continuous measure and categorized into burden groups with non/minimal as reference, and included age at follow-up date, sex, college education, deprivation, sleep disorders, and ethnic background. Sleep score trajectory model calculated the change in sleep score from baseline to follow-up and categorized as improved (score change ≤−1), no change (0; reference group), mild worsening (+1), significant worsening (≥+2) and calculated additional risk after inclusion of demographics, sleep disorders, baseline sleep score, and the time lag from baseline to follow-up.

*Risk per 1-point increase.