A study of opioid prescribing in each U.S. congressional district finds the highest rates are in the Southeast, Appalachia and the rural West, HealthDay reports.

The highest opioid prescribing rate was in Alabama’s 4th congressional district (166 prescriptions per 100 people), followed by districts in Kentucky, Tennessee, Mississippi, Arkansas, Virginia and Oklahoma, the researchers report in the American Journal of Public Health.

The lowest rates were in congressional districts near cities, including New York, Boston, Atlanta, Los Angeles, San Francisco and Washington, D.C.

“Because a congressional district has a named elected representative, unlike say a county, it brings a certain degree of political accountability when it comes to discussing the opioid epidemic,” said researcher S.V. Subramanian, a professor of population health and geography at Harvard.