New study questions effectiveness of invasive procedures for chronic pain

An extensive review of 25 randomized clinical trials found "little evidence" that invasive surgery was more effective than other procedures in reducing chronic pain, according to the study published September 10 in the journal Pain Medicine. .

The findings raise several questions for clinicians, researchers, and policy-makers, said lead author, Wayne Jonas, MD, clinical Professor of Family Medicine at the Uniformed Services University and at Georgetown University School of Medicine.

“First, can we justify widespread use of these procedures without rigorous testing?" said Jonas, who is also the executive director of Samueli Integrative Health Programs.

An estimated 100 million Americans suffer from chronic pain, with costs estimated at more than $500 billion annually. With the development of new minimally invasive procedures, Americans spent an estimated $45 billion on surgery for chronic low back pain and $41 billion for arthroplasty for chronic knee pain in 2014, the study said. Non-opioid treatments, like surgery, are being increasingly used.

But researchers concluded that "evidence does not support the use of invasive procedures as compared with sham procedures for patients with chronic back or knee pain. Given their high costs and safety concerns, more rigorous studies are required before invasive procedures are routinely used for patients with chronic pain."

The findings are based on a systematic review of studies from 28 publications between 1959 and 2013 involving surgeries on 2,000 patients. Procedures performed included open surgeries, arthroscopic, endoscopic, laparoscopic, heart catheterization, radiofrequency, laser, and other interventions. In each study, researchers had also performed sham procedures on a control group where they faked the invasive procedure by omitting the step believed to be therapeutically necessary. They then compared reduction in pain intensity, disability, health-related quality of life, use of medication, adverse events, and other factors at various time periods after the procedures. Patients did not know which intervention (real or sham) they had and in most cases, evaluators were also blind to which procedure a patient received.

Outcomes varied across the studies: in 14 studies that had sufficient data, the risk of any adverse event was significantly higher with surgery (12 percent) than with the sham group (4 percent). Globally, the studies appeared to favor active treatment over sham treatment; however, the quality of the studies varied and the majority reported small effects. Overall, the reduction in disability post-procedure did not differ between the two groups at three months or at six months. A meta-analysis on outcomes in seven studies of low back pain and three on knee osteoarthritis showed no difference in pain at six months compared with sham procedures.

The study notes that many types of invasive procedures are marketed, used, and paid for without evidence from rigorous study designs involving randomization, blinding, and placebo.

"Because of the high costs and risks associated with these procedures and the vast number of people who are exposed to those risks, we need to focus on building evidence to support these methods," said Jonas.

Authors noted several limitations in their meta-analysis: there were few studies of any one pain condition, resulting in substantial heterogeneity across populations and interventions; many types of invasive procedures for pain have not been subjected to sham-controlled studies; and none of the studies were double-blind because clinicians were aware of which procedures were actual versus sham.

The study was funded by the Samueli Institute, a nonprofit research organization dedicated to investigating the safety, effectiveness, and integration of healing-oriented practices to allow for evidence-based decision-making.