For all their risks, opioids had no pain-relieving advantage in a yearlong clinical trial

For years, doctors turned to opioid painkillers as a first-line treatment for chronic back pain and aches in the joints. Even as the dangers of addiction and overdoses became clearer, the drugs' pain-relieving benefits were still thought to justify their risks.

Now researchers have hard evidence that challenges this view.

In the first randomized clinical trial to make a head-to-head comparison between opioids and other kinds of pain medications, patients who took opioids fared no better