health care outcomes were also taken into account in this study because differences in

disease prevalence and mortality exist among the races (lezzoni, 2003). Because of

socioeconomic disparities in health status and outcomes, we also controlled for income

and education factors (Braveman & Tarimo, 2002).

 Proxy measures of illness severity were employed in the analysis to further control

for differences among patient populations. Self-perceived mental and physical health

status and number of comorbidities were used to control for illness severity. Self-

perceived mental health status and self-perceived physical health status were variables

defined in MEPS and these are considered risk factors in health care outcomes (lezzoni,

2003). Self-perceived mental and physical health status were reported by patients on a

likert scale of excellent, very good, good, fair, and poor. Comorbidites were a significant

consideration because patients with comorbidities tend to have higher risks of death,

complications, functional impairments, and higher health service use (lezzoni, 2003).

Comorbidities were determined from the MEPS HC medical conditions file in the

number of different ICD-9 codes in an individual's file were tallied.

 Health insurance status was an additional variable that was created in order to

control for health service utilization. The MEPS HC full year consolidated file was used

to identify patients who were insured (i.e., insured all months of the year), intermittently

insured (i.e., at least one month of the year without health insurance), and uninsured (i.e.,

no health insurance for all months of the year). This was a control variable because it is

expected that individuals insured throughout the year would have higher expenditures

than those intermittently insured and uninsured throughout the year.