Table 1.

Rationale for Patient-Level Variable Selection.

Determinants of health41	Variables in our studya	Measures of medical complexity	Measures of social complexity
Social environment	Age	+
	Sex
	Race		+
	Ethnicity		+
	Marital status		+
	Distance from assigned station		+
Physical environment	Homelessness		+
Prosperity	Copayment status based on povertyb		+
Disease			+
Physical disease	VA medical complexity score (DCG)44	+
Mental disease	Psychiatric conditions (non-PTSD and nonmood disorders)		+
	PTSD		+
	Mood disorders		+
	Dementia		+
Behavior	Substance abuse		+
Health and function	Copayment status based on disability		+

Note. VA = Veterans Administration; DCG = Diagnostic Cost Group; PTSD = posttraumatic stress disorder.

^aThe Evans and Stoddart model also includes categories for genetic factors and well-being. Variables representing these categories were not available for use in our study.

^bFor determination of VA patient copay status, patients are first considered for exemption from copay on the basis of disability. If they do not qualify for exemption based on disability, they are considered for exemption based on poverty. Therefore, the group classified as “low income” variable does not represent low income disabled veterans.