Even as the misuse of prescription painkillers is a growing public health concern in the United States, a new study shows that almost 75 percent of patients who are prescribed opiate pain relievers following a major injury or trauma get off the medication almost a month after discharge.

Presented at the 2016 Clinical Congress of the American College of Surgeons in Washington D.C., the study found that only about 1 percent of the patients were still taking prescription opiates, or opioids like hydrocodone, oxycodone, morphine or fentanyl – a year after discharge from the hospital.

“We were really surprised by how low the numbers were for long-term opiate use,” said Andrew Schoenfeld, an orthopedic surgeon at Brigham and Women’s Hospital and assistant professor at Harvard Medical School, Boston, in a press release. “It appears that traumatic injury is not a main driver for continued opioid use in patients who were not taking opioids prior to their injuries.”

For the study, researchers used the 2007 to 2013 database of the Department of Defense health care system with patients between the ages of 18 and 64 years who suffered from severe injuries – an Injury Severity Score of nine or higher.

While over half of the patients filled at least one opiate prescription after discharge, less than 9 percent continued three months later, with the numbers falling to under 4 percent at six months. At one year, only 1.1 percent of the patients were filling opiate prescriptions.

The researchers also gauged the effect of a number of other factors on the likelihood to continue opiate painkiller use. An example of this was age — older patients were more likely to continue use than young adults. Lower socioeconomic status also increased the use of the medication. Marriage was another factor that saw an increased likelihood with married patients continuing opiate use for longer.

“We wish to emphasize that health care providers should not withhold opiate painkillers because a patient has any of the identified risk factors from this study,” Schoenfeld said. “At-risk patients can benefit from closer follow-up with their health care providers and, for those at high risk, a referral to the hospital's pain management service.”