Most people with acute low back pain improve within two to 12 weeks, but those who don’t may experience persistent pain and require alternative treatment strategies, a research review released last Monday has suggested.

The systematic review by an international research team that pooled the results of 95 earlier studies has flagged the need for “timely reassessment” after 12 weeks to identify those with persistent pain episodes and escalate care if needed.

“Most (patients with) episodes of back pain recover — this is the case even if you’ve already had back pain for a couple of months,” said Lorimer Moseley, a pain specialist at the University of South Australia who led the review. “But once you’ve had back pain for more than a couple of months, the chance of recovery is much lower,” Moseley said in a media release outlining the review’s findings.

Moseley and his colleagues tracked the clinical course of low back pain in a sample of over 17,900 patients — some of whom had acute pain that lasted less than four weeks, some had subacute pain that lasted between four and six weeks, and others had persistent pain extending beyond 12 weeks.

Pain and mobility issues in most patients with new back pain lessened significantly within six weeks, but then recovery slowed. And many patients with persistent back pain lasting over 12 weeks continued to have moderate-to-high levels of pain and disability.

“These findings make it clear that back pain (in some patients) can persist even when the initial injury has healed,” Moseley said.“In these situations, the back pain is associated with pain hypersensitivity, not ongoing back injury. This means that if you have chronic back pain — pain on most days for more than a few months — it is time to take a new approach to getting better.”

For such patients, the researchers have said, advice might be best focused on the likelihood of symptom recurrence and acknowledging that ongoing symptoms do not necessarily reflect serious pathology, or a progressive disease process.

Patients whose pain persists for 12 weeks or longer and whose pain or disability levels remain high, should be considered for alternative escalated treatment options, the researchers said. Their study was published on Monday in the Canadian Medical Association Journal.

Moseley said some new treatments based on training both the brain and the body focus on getting patients to understand that chronic back pain is not a simple problem and then slowly reducing pain system sensitivity while increasing their activities.