A new study finds that notifying doctors about a patient’s fatal opioid overdose reduced the number of opioid prescriptions they wrote for up to a year, UPI reports.

Researchers at the University of Southern California studied the effect of a letter notifying clinicians that their patient has died from an overdose. They sent the letter to 809 clinicians who had prescribed opioids to 166 people who had died of an overdose. The researchers compared the prescribing patterns of these clinicians to those who had not received the letter.

They found after one year, those who received the letter wrote 7% fewer prescriptions than those who had not received notification.

“Clinicians don’t necessarily know a patient they prescribed opioids to has suffered a fatal overdose,” study lead author Jason Doctor said in a university news release. “We knew closing this information loop immediately reduced opioid prescriptions. Our latest study shows that change in prescribing behavior seems to stick.”