State drug prescription monitoring programs help prevent 10 opioid-overdose deaths daily in the United States, a new study finds. Implementing the programs in all states, and improving less effective programs could save another two people daily, the researchers said.

Missouri is the only state with no drug monitoring program. Its opioid overdose rate has increased more quickly than the national average, the study found.

Drug prescription monitoring programs are designed to prevent “doctor shopping” by patients, and to identify doctors who prescribe unusually large doses of opioids. The programs that tracked the most potentially addictive medications and updated their databases at least once a week had the biggest decreases in overdose deaths, Reuters reports.

The Vanderbilt University researchers reported in Health Affairs that states with the strongest programs had 1.55 fewer deaths per 100,000 people, compared with less robust programs.

“Today, opioid overdose deaths are more common than deaths from car crashes. Our study provides support that prescription drug monitoring programs are part of what needs to be a comprehensive approach to the prescription opioid epidemic,” lead author Stephen Patrick said in a news release.