Drivers who caused deadly two-vehicle accidents in North Carolina and around the country were much more likely to test positive for opioid prescription painkillers than drivers who did not cause the crash, according to a study. The research was published in JAMA Network Open in February.

For the study, researchers examined crash data from 18,321 fatal two-vehicle accidents in the Fatality Analysis Reporting System, which is compiled by a division of the National Highway Traffic Safety Administration. They found that “failure to keep in lane” was the most common cause of the accidents, accounting for 7,535 of the crashes studied. Of the drivers who were blamed for the crashes, 918 tested positive for opioids. Of the drivers who did not cause the accidents, only 549 had opioids in their system.

Researchers found that a total of 1,467 drivers had opioids in their bloodstream. Of those, 32 percent had hydrocodone in their system, 27 percent had morphine in their system, 19 percent had oxycodone, 14 percent had methadone and 9 percent had other types of opioids. The authors of the study said that the research results did not prove that opioids cause deadly car crashes. They said that the findings instead show an association between the two events.

Victims of car accidents could be owed compensation for medical expenses, rehabilitation costs, pain and suffering, lost wages and property loss. A personal injury attorney could review crash scene investigation reports, witness testimony and toxicology results to build a strong case on behalf of a victim. The attorney could then work to negotiate a settlement with the at-fault driver’s insurance company. If the amount offered is insufficient, going to court might be necessary.