Table 4.

Linear regression analysis, endpoint: ISI.

Univariate analysis	Beta	SE	P	Multivariate analysis¶	Beta	SE	P
Anxiety only	0.2	0.6	0.70	Anxiety only	0.2	0.6	0.75
Depression only	0.8	1.0	0.40	Depression only	1.0	1.0	0.30
only one of anxiety or depression	0.5	0.6	0.41	Only one of anxiety or depression	0.5	0.6	0.38
Anxiety + Depression	4.2	0.6	<0.0001	Anxiety + Depression	4.1	0.6	<0.0001

ISI, insomnia severity index;

^¶adjusted for age, gender, education level, and size of residential area; SE, standard error; P, p-value.