Table 1.

Baseline Demographic and Clinical Characteristics^a

Characteristic	BBTI (n=39)	IC (n=40)		Statistical Findings
Age, y	72.5 (6.6)	70.8 (7.8)		t77=1.04, P=.30
Female	26 (67)	28 (70)		${\mathrm{\chi }}_1^2=0.10$ , P=.75
White	36 (92)	38 (95)		Fisher exact, P=.68
Subjective socioeconomic status score (1, highest; 9, lowest)	4.0 (1.6)	3.4 (1.4)		t77=1.83, P=.07
Education
≤High school	7 (18)	7 (18)		Fisher exact, P=.96
Trade or technical school	4 (10)	3 (8)
College	15 (38)	18 (45)
Postgraduate	13 (33)	12 (30)
Medical and psychiatric status
Chronic health conditions	5.5 (2.6)	5.5 (3.0)		t77=−0.06, P=.95
Current medicationsb	5.3 (3.0)	5.1 (3.1)		t77=0.30, P=.76
Currently taking sleep medication	12 (31)	17 (43)		${\mathrm{\chi }}_1^2=1.17$, P=.28
Major depression (PHQ)	0	0		NA
Other anxiety disorder (PHQ)	1 (3)	0		NA
Alcohol abuse (PHQ)	0	0		NA
Currently taking antidepressant	7 (18)	2 (5)		Fisher exact, P=.09
Screening polysomnography
Apnea-hypopnea indexc	9.0 (5.4) (n=38)	7.9 (5.5) (n=39)		t76=0.88, P=.38
Apnea-hypopnea index >5	28 of 39 (72)	25 of 29 (64)		${\mathrm{\chi }}_1^2=0.53$, P=.47
Desaturation indexd	3.0 (3.3) (n=38)	3.0 (3.3) (n=39)		t75=0.72, P=.47
Periodic limb movement arousal indexb	6.0 (4.5) (n=38)	5.6 (5.1) (n=39)		t75=0.51, P=.61

Abbreviations BBTI, brief behavioral treatment for insomnia; IC, information control; NA, not applicable; PHQ, Patient Health Questionnaire.²⁷

^aUnless otherwise indicated, data are reported as number (percentage) or mean (SD).

^bSquare root (x+0.1) transformation used for statistical analysis.

^cSquare root transformation used for statistical analysis.

^dNatural log (x+0.1) transformation used for statistical analysis.