Eligible studies were randomised controlled trials (RCTs) or cohort studies that compared the effectiveness of interspinous device placement or surgical decompression versus each other or versus conservative management in patients aged at least 40 years with lumbar spinal stenosis. Patients with trauma, significant lumbar instability, previous lumbar spine surgery or spondylolisthesis above Grade I were excluded. Outcomes of interest were measures of disability, pain, function and morbidity. Complication rates were reported.
Included studies were in patients who had failed conservative management. Some patients were receiving pain relief. Where reported, the mean age of patients ranged from 62 to 70 years. Conservative management consisted of non-steroidal anti-inflammatory drugs and physical therapy, with or without analgesics and epidural injections. Inclusion criteria for individual trials varied. Methods to measure outcome data varied.
The authors did not state how many reviewers screened studies for inclusion.