A University of Iowa study reveals significant disparities between minority and white clients in success rates for completing substance abuse treatment programs. Moreover, these disparities vary widely from state to state.

"Our findings suggest that for most states there's something amiss," says Stephan Arndt, Ph.D., UI professor of psychiatry and biostatistics. "There are strong racial and ethnic disparities for people in being able to complete substance abuse treatment programs successfully, and those disparities are something we need to set as targets to remove.

"On the positive side, the study clearly shows that some states have been able to eliminate disparities," he adds. "We need to examine the states that are being successful and compare what they are doing with those states that are not doing so well—what can we learn from successful states?"

Successful completion of substance abuse treatment programs is important because it predicts greater likelihood of getting off drugs, abstinence from alcohol, and being employed six and 12 months after treatment completion. It also predicts lower criminal justice involvement.

"It is a public health and public safety outcome," Arndt notes.

The study, which was published online in May in the journal Drug and Alcohol Dependence, analyzed data from 940,058 patients from outpatient substance abuse treatment centers across the United States for whom there were admissions/discharge information, as well as racial or ethnic classifications of white, Latino, or black/African-American. The data came from the 2006 to 2008 Treatment Episode Datasets Discharge (TEDS-D).

While previous studies have focused on client-specific factors, Arndt and his colleagues were interested in the role of state-level organizations and systems.

After adjusting for client-specific factors shown to influence successful treatment completion, such as sex, age, and employment status, the study showed that race or ethnicity remained a significant predictor of successful completion.

Over all states, 46.25 percent of whites, 45.6 percent of Latinos, and 37.5 percent of African-Americans successfully completed substance abuse treatment programs. In addition, there were significant disparities among the states in regard to ethnic/racial differences.

Most states, including Iowa, show racial and ethnic disparities, where minority populations do worse than whites. However, a few states showed higher completion rates for blacks and Latinos.

For African-Americans, Tennessee had the worst disparity—African-American clients were 35 percentage points less likely to complete a treatment program than were whites. African-American clients also fared poorly in Idaho and Minnesota. However, there were three states where they had slightly higher rates of success than whites—Hawaii, Utah, and Mississippi.

Disparities between completion rates for whites compared to Latinos were generally less severe. Vermont had the largest negative disparity of almost 22 percent followed by North Dakota at 17 percent. However, in 17 states, Latino clients were more successful than white clients. Interestingly, Southwestern states, which have large Latino populations, did not have larger disparities than other states. On the other hand, states with low densities of minority populations, like West Virginia, also had small disparities. Four states—Kansas, Oregon, Texas, and Florida—had disparities that were significantly positive for Latinos.

"We were actually surprised by the scale of the differences—that states had such varying degrees of success," adds Arndt, who also is director of the Iowa Consortium for Substance Abuse Research and Evaluation. "Although some states were doing well, most states were not and some were doing quite poorly."

Arndt says he and his colleagues were also surprised to find a pattern of differences that did not conform to certain stereotypes about certain states.

"I anticipated that Southern states might have the worst disparities between minorities and whites, or at least that Southern states would share similar results," Arndt says. "But, while Tennessee has the worst disparity between African-American clients compared to white clients, Mississippi is the third best state and had almost no difference in completion rates for whites and African-Americans."

Although the research was able to quantify state-to-state disparities in completion rates, the study did not determine the causes of the disparities.

Arndt says that one possible factor is the use and availability of so-called ancillary, or recovery, services. Previous research suggests that minorities undergoing substance abuse treatment may need more of the services, which include help with employment, housing, and mental health care, and they seem to be more sensitive to a lack of these services.

"States that do not have recovery services available may need to make them more available," Arndt says.

In addition to Arndt, the UI research team included Laura Acion and Kristin White.