Table 3.

Cox Regression Analysis of Onset of Delirium by Average Sleep Quality in Prior 28 Days

Cox Regression Analysis of Onset of Delirium by Average Sleep Quality in Prior 28 Days
Predictor Variables	Hazard Ratio	95% Profile Likelihood Confidence Limits for Hazard Ratio		Wald χ2 (1 df)	p
Analysis 1
Sleep quality rating in last 28 days1, unadjusted	2.37	1.50	3.74	13.64	0.0002
Analysis 2
Sleep quality rating in last 28 days	2.45	1.54	3.89	14.59	0.0001
Caregiver other than family or friend	2.01	0.78	4.66	2.40	0.1210
Analysis 3
Sleep quality rating in last 28 days,	2.29	1.45	3.59	3.59	0.0003
Any Psychiatric Diagnosis	1.90	0.84	4.83	4.83	0.1446
Analysis 4
Sleep quality rating in last 28 days,	2.46	1.52	3.94	13.93	0.0002
Cancer Diagnosis	0.65	0.31	1.40	1.25	0.2640

Test: Cox regression models were used with sleep quality as a time-dependent covariate

¹Sleep quality rating is the average PSQI 4 (Overall Sleep rating) obtained in the 28 days prior to the event time. Sleep quality ratings after the onset of delirium are not included in the analysis.

N= 70 subjects, 29 subjects had delirium onset with data on sleep quality obtained in the 28 day interval prior to onset.

Analyses 2 – 4 are individually-adjusted analyses for the second variable listed and show the adjusted HR for sleep quality in the last 28 days and the HR for the second variable