Aetna, one of the nation’s largest health insurance companies, is contacting doctors who prescribe significantly more opioids than their peers, The Washington Post reports.

The company notified 951 physicians who were identified as falling within the top 1 percent of opioid prescribers within their specialty. The notices were based on an analysis of more than 8.6 million insurance claims. Only physicians who prescribed opioids at least 12 times were included in the data. Oncologists and other doctors who are likely to dispense large amounts of opioids were excluded.

Aetna said if the 931 doctors brought their opioid refill rate in line with the average for all doctors who prescribe the drugs, 1.4 million fewer pills would be dispensed each year.