A new study by a Duke University law professor finds that minority and lower income employees of Duke University and Duke University Health Systems are less likely to take advantage of mental health and prescription benefits than white and higher-income consumers.

The study examined the use of benefits by employees who have identical insurance benefits, including equal co-payments. “Insurance Expansions: Do They Hurt Those They Are Designed to Help?” by Professor Barak Richman is published in the journal Health Affairs. According to Richman, the findings are contrary to the common wisdom that has driven a trend toward healthcare mandates at the state and federal levels.

Richman’s study examined the insurance claims of more than 20,000 employees of Duke University and Duke University Health Systems from 2001 to 2004. About 68 percent of the employees were white and 24 percent were African American; the median annual income rose from $36,000 to $40,500 over the four years of the study. These figures roughly reflect the demographic profile of both Durham County, where Duke is located, and the state of North Carolina.

The study showed that whites were significantly more likely than African Americans or Asians to file claims for mental health benefits. Income also factored into employees’ use of benefits. As incomes rose, employees became significantly more likely to file claims. Similarly, whites were more likely than African Americans and much more likely than Asians to use pharmaceutical benefits, and as incomes rose so did use of drug benefits.

As a result, whites received nearly four times the annual insurance dollars that African Americans received and more than three times the dollars that Asians received in health insurance disbursements for mental health claims. Whites received $140 to $225 more in insurance coverage for drug claims than African Americans did, and about $500 more than Asians.

Richman said he believes the data are representative of national trends.