The impact of deployment experience and prior healthcare utilization on enrollment in a large military cohort study

Table 3 Adjusted odds of enrollment status with prior healthcare utilization in the Millennium Cohort Study by panel, among active-duty personnel

	Panel 2 (2004-2006)		Panel 3 (2007-2008)
	N = 86,401^a		N = 144,954^a
Exposure^b,c	OR	95% CI	OR	95% CI
Number of outpatient visits^d
None	1.00	Ref	1.00	Ref
1-3 visits	1.13*	1.05, 1.20	1.26*	1.20, 1.33
4-12 visits	1.17*	1.10, 1.25	1.41*	1.34, 1.48
>12 visits	1.14*	1.06, 1.23	1.44*	1.36, 1.52
Cumulative days hospitalized^d
None	1.00	Ref	1.00	Ref
1-2 days	0.88*	0.80, 0.97	0.96	0.89, 1.03
More than 2 days	0.75*	0.68, 0.83	0.89*	0.83, 0.96
Any diagnosed mental disorder^e
No	1.00	Ref	1.00	Ref
Yes	0.79*	0.75, 0.83	0.89*	0.85, 0.93
Any reported injury^f
No	1.00	Ref	1.00	Ref
Yes	1.03	0.99, 1.07	1.10*	1.07, 1.13

OR, odds ratio; CI, confidence interval; Ref, reference category.
*Indicates significance at the P < 0.05 level.
^aOnly active-duty personnel with complete demographic and covariate information were included.
^bExposures were evaluated during the 12 months prior to each enrollment cycle (1 June 2003 – 1 June 2004 for Panel 2 and 5 June 2006 – 5 June 2007 for Panel 3).
^cEach exposure was modeled separately with enrollment status and adjusted for sex, age, education, marital status, race/ethnicity, service branch, deployment experience, and military occupation. Military pay grade was excluded from these models due to small numbers of officers in these young, active-duty populations.
^dAny cause healthcare utilization in the 12 months prior to the first day of the enrollment cycle.
^eAny reported principal diagnosis for a mental disorder, as defined by ICD-9 codes 290-319.
^fAny reported principal diagnosis for an injury, as defined by ICD-9 codes 800-959, 990-999.

ISSN: 1471-2288