Skipping screening tests and going straight to zapping nerves to relieve suspected arthritis-related back pain could save thousands of dollars while helping treat patients the screening tests might miss, according to new research.

In diagnosing arthritis-related lower back pain, doctors have been debating for years whether patients need one or two screening tests, called nerve blocks, before they should get treatment. But a study published in the August issue of Anesthesiology suggests it might be more cost-effective, and better for patients, to forgo nerve blocks entirely and instead move straight to nerve ablation therapy for patients suspected of arthritis-related back pain after a clinical exam.

"The question in my mind becomes, what do people want?" asked Dr. Steven P. Cohen, lead author of the study, and associate professor at Johns Hopkins School of Medicine and the Uniformed Services University of the Health Sciences. He also directs chronic pain research at Walter Reed Army Medical Center, where part of the work was carried out. "Do you want pain relief and functional improvement, or do you want increased diagnostic accuracy?"

In the nerve-ablation procedure, doctors insert a needle under the skin and track it to its location using real-time X-ray scans, called fluoroscopy. The needles beam out radiofrequency waves that heat and burn the nerves to temporarily dull the pain. Typically, the procedure has published success rates above 60 percent. Pain relief, when it occurs, can last between six months and two years, as the nerves grow back.

But only patients who suffer from arthritis-related back pain, a degeneration of the facet joints, and who are thought to be about one out of 10 sufferers of chronic back pain, benefit from the procedure. So to screen out patients with other sources of pain, such as damaged discs, doctors use the nerve block screening test. In this, physicians usually inject an anesthetic, such as lidocaine, coupled with a steroid, into nerves leading to the facet joints to see if it brings pain relief.

But the nerve blocks aren't terribly accurate, Cohen said.

"Between 25 and 40 percent of people will get pain relief with one block even though they really don't have arthritis causing their pain," Cohen said. The reasons could be the placebo effect, the anesthetic drug numbing other nerves, or the effects of sedation, when used, he said.

Nerve blocks also potentially miss patients by disqualifying ones who really do have arthritis-related back pain and could benefit from the treatment. Studies on the false-negative, or miss rate are scant, Cohen said, with the only evidence really being a nearly 15-year-old study, which in any case looked at a different area of the back. The study found the miss rate was close to 50 percent, he said.

"You can miss a very high percentage," Cohen suggested.

Both procedures have similar complication rates, Cohen said, which are caused by inserting the needle into the spine.

"The chance of serious complications is incredibly low, much, much less than 1 percent," he said. The most common side effect of the RF ablation therapy is temporary, increased pain from inflamed nerves, which can occur in 10 percent of patients, Cohen said.

In the study, the researchers looked at 151 patients, largely from the military, at Johns Hopkins, Walter Reed and other affiliated sites.

The patients were randomly separated into three groups of about 50 people each. One group got radiofrequency ablation based on clinical findings, another got the treatment after only one diagnostic block, and the last after two blocks -- the standard of care.

The researchers found that of all the patients in each group, one-third in the first group had relief lasting at least three months, compared with 16 percent in the second and 22 percent in the third group. Drilling down, though, the researchers found those in the group getting two nerve blocks before treatment had one of the best treatment success rates. Of the 14 patients who ultimately got the radiofrequency procedure in that group, nine successfully had their pain relieved, Cohen pointed out.

"So it's very successful for those people," Cohen said. "They really probably had arthritis causing their pain."

But overall, going straight to the RF ablation was the most cost-effective, according to the researchers' models.

The team calculated the cost of successful treatment by taking the total cost of all procedures, a missed work day, and a decrease in monthly medication expenses due to pain relief. According to the model, the costs of going straight for radiofrequency therapy without nerve blocks was $6,286; for only one block before the therapy, $17,142; and for two blocks before RF, $15,241.

Inspired by the military

Cohen got involved in the study after his experience in the military, he said. Soldiers in Iraq or Afghanistan needing treatment have to be flown into camp by helicopter, which is always risky, and generally have less than a week to get mended before being sent back to duty, hardly enough time for the many days it takes for two nerve blocks and then the radiofrequency ablation treatment.

"You're transporting people around in Blackhawk helicopters," Cohen said. "These things crash; it's expensive and dangerous."

Still, Cohen notes that nerve blocks will remain necessary for some patients, especially ones who are candidates for surgery.

For now, he hopes the study, and possibly others like it, will help convince Medicare, health insurance companies and other payers to take a closer look at the issue.

"Hopefully, someone will look at this, and say, this is cost effective for the country," he said. "More people get better for less cost."