CHICAGO (AP) — New federal data show that Illinois emergency rooms saw a 66 percent increase in opioid overdose visits last year.

The Chicago Tribune reports the Centers for Disease Control and Prevention on Tuesday released state emergency room data. Acting CDC director Dr. Anne Schuchat said emergency room visit data is useful because it shows when and where people are overdosing. She says states can use that information to identify where resources are needed.

The CDC report found the opioid-related emergency room visits rose an average 35 percent across 16 states between July 2016 and September 2017. The Midwest and large metropolitan areas saw the largest increases.

Schuchat called the report “concerning,” but said there are opportunities for hospitals, law enforcement and community groups to create partnerships to address the crisis.