(NewsNation) — While fentanyl may be the deadliest drug in America, many people are introduced to opioids at the clinical level, pushing researchers to look for overprescribing solutions aimed at curbing the problem before addiction sets in.

It may start with doctors thinking carefully about the prescriptions they write. Researchers at the University of Southern California paired with the medical examiner’s office in San Diego to formally notify doctors when a patient they prescribed opioids died of a drug overdose.

The group sent letters to over 800 clinicians who had prescribed opioids to over 100 people who died from overdoses, according to USC professor Jason Doctor, who was part of the study published earlier this year.

The letters both informed the clinicians — who were mostly medical doctors — of these deaths while also providing information on safer prescribing based on guidelines from the Centers for Disease Control.

Clinicians who received letters wrote 7% fewer opioid prescriptions over the next year, the study found.

These letters could serve as a low-cost intervention to reduce opioid overdoses. But Doctor cautioned that how the letter is written could matter. He pointed out that there have been several attempts by different organizations to send these kinds of letters to doctors, and that some of them haven’t been as successful.

“The Medical Board of California did a letter where they were kind of threatening… and that letter was taken very badly,” he said.

One physician, who received one of those letters, said he was horrified.

Jason Doctor’s approach, on the other hand, took pains to avoid making the clinicians defensive.

“Learning of a patient’s death can be difficult,” his letter reads. “We hope you take this as an opportunity to join us in preventing future deaths from drug overdose.”

“I think the key is to give them some way to resolve the tension that you’ve created by sending this letter. Like, ‘Hey we understand this is difficult and you may not have known but here’s what you need to do better,'” he said.

Researchers also recognized the danger of cutting back on prescriptions too sharply in response to the letter, so the group monitored for drastic reductions. Doctor said they didn’t find any.

“So that suggested the letter resulted in moderate reductions in prescribing,” Doctor said.

While it was published in January, the USC study involved prescriptions issued between 2015 and 2016. Over the past few years, medical providers have revised their prescribing of opioids. By 2020, the rate of prescription opioid dispensing fell to its lowest level in 15 years.

Increasingly synthetic opioids like fentanyl are a greater danger than prescriptions, meaning that interventions like the ones Doctor ran may be less relevant to the current wave of deaths.

Nonetheless, Doctor stressed this kind of intervention could provide useful information for many physicians.

“I think what’s kind of shocking is that physicians don’t get a lot of feedback on how they’re doing,” he said, adding that physicians don’t typically learn when their patients die of overdoses.