African-Americans are significantly less likely to complete addiction treatment than white or Hispanic patients, according to a new study from Rand's Drug Policy Research Center.

The study of intake and discharge records from outpatient and residential alcohol treatment centers in Los Angeles County compiled between 1998 and 2000 found that 19 percent of black patients completed outpatient treatment, compared to about 27 percent of whites. Among residential-treatment patients, 31 percent of blacks completed treatment, compared to 46 percent of whites.

Hispanics completed treatment at about the same rate as whites.

Lack of economic resources, neighborhood differences, and other factors helped explain the disparity in many of the outpatient cases, but only 7 percent of the inpatient disparities could be explained by such factors.

Researchers also found that African-Americans and Hispanics were far less likely to receive residential treatment than whites, and said that one-fifth of the disparity between blacks and whites could be eliminated if blacks were placed appropriately in residential care.

"These findings suggest some of the contributors to a significant alcohol treatment disparity between whites and minorities in Los Angeles County and begin to indicate what might be done about it," according to Rand. "However, there is much about the disparity -- such as the roles of patient economic resources and treatment facility neighborhoods -- that is not yet understood, and it is uncertain whether these factors are the same in other locations."