Table 3.

Adjusted levels of health care resource use and direct cost differences among those with only one insomnia symptom and those without insomnia

	Number of physician visits		Number of ER visits		Number of hospitalizations		Direct costs
	Mean	SE	Mean	SE	Mean	SE	Mean	SE
Difficulty falling asleep only (n=4,195) (A)	2.73F	0.03	0.19	0.14	0.13	0.16	$5,853F	0.06
Waking several times only (n=2,586) (B)	2.62F	0.03	0.22	0.16	0.17	0.19	$6,363F	0.08
Waking up too early only (n=2,421) (C)	2.53F	0.04	0.19	0.17	0.12	0.20	$5,536	0.08
MOTN awakenings only (n=2,115) (D)	2.61F	0.04	0.21	0.18	0.15	0.21	$6,088	0.08
Poor quality of sleep only (n=1,512) (E)	2.92F	0.04	0.18	0.21	0.08	0.26	$5,449	0.09
No insomnia (n=31,811) (F)	2.19ABCDE	0.02	0.17	0.08	0.12	0.10	$4,928	0.04

Notes: Superscript letters indicate which groups are significantly different from the reported adjusted mean (P<0.05). Resource use was assessed in the past 6 months. Direct costs were on a per-respondent annual basis. All reported means were adjusted for age, sex, race/ethnicity, education, household income, BMI, alcohol use, smoking behavior, exercise behavior, and the CCI.

Abbreviations: BMI, body mass index; CCI, Charlson comorbidity index; MOTN, middle-of-the-night; SE, standard error; ER, emergency room.