Table 3.

Adjusted rate ratios (95% confidence intervals) of all-cause health care utilization among insomnia cases compared to non-sleep disordered controls in the year prior^a to insomnia diagnosis or matched index date among Medicare beneficiaries 2007–2011, N = 484 707

	Model 1b	Model 2c	Model 3d
Inpatient	2.56 (2.52, 2.60)	2.66 (2.62, 2.70)	1.61 (1.59, 1.64)
Emergency department	2.48 (2.45, 2.51)	2.41 (2.38, 2.44)	1.49 (1.47, 1.51)
Outpatient	1.56 (1.55, 1.57)	1.56 (1.54, 1.57)	1.20 (1.19, 1.21)
Prescriptions	1.41 (1.40, 1.41)	1.44 (1.43, 1.45)	1.17 (1.16, 1.17)

^aMonth of diagnosis excluded.

^bAdjusted for year of diagnosis.

^cAdjusted for year of diagnosis, age, sex, and race.

^dAdjusted for year of diagnosis, age, sex, race, and comorbidities listed in Appendix 1.