A new clinical trial has found that steroids treat sciatica pain no better than a placebo, and that taking oral steroids leads to only a moderate improvement in function for sciatica patients.

“When we compared the [oral steroid] prednisone to placebo, there was a modest improvement in function,” researcher Dr. Harley Goldberg, director of spine care services at Kaiser Permanente San Jose Medical Center in California, told the medical news site HealthDay. “[However] when we compared the pain [between the two groups], there was actually no difference.”

Sciatica refers to lower back and leg pain that is usually caused by a herniated disc in the lumbar spine. The condition affects about 10% of people at some point in their lives, according to the researchers — and, indeed, lower back pain is the leading cause of disability for Americans younger than 45.

Doctors often prescribe oral steroids to ameliorate sciatica pain, but Goldberg and his colleagues realized that course of action had never been tested in a clinical setting.

The team recruited 269 adults, all of whom had sciatica caused by herniated discs (confirmed by MRI). The participants were randomly assigned to take either oral steroids or a placebo. The researchers then followed up with both groups for up to a year, asking about pain and ability to perform daily tasks.

Not only were those who took the oral steroid no better off in terms of pain levels, they were also more likely to report side effects early on, such as insomnia, nervousness or increased appetite. After a full year, however, both groups reported side effects at similar levels.

Though the trial’s findings don’t “slam the door” on steroid treatment for sciatica, according to Goldberg, they do call into question whether it should be a routine treatment. The more information doctors and patients have at their disposal when making a treatment decision, the better, he said.

“Some people could still choose to use it,” he commented.

The full study was published in the Journal of the American Medical Association May 19 under the title “Oral Steroids for Acute Radiculopathy Due to a Herniated Lumbar Disk: A Randomized Clinical Trial,” and is available online.