Low-back pain

We thank Dr. Gunn for his letter1 regarding our article.2 We acknowledge that nonspecific low-back pain may have a variety of causes; however, current diagnostic techniques, including physical examination, are unable to reliably identify the source of pain in most patients.3 As well, although identifying treatment effect modifiers (characteristics that identify subgroups of patients who might respond better to a particular treatment) may yet be possible, evidence for their existence is not yet convincing.4 We would be interested in any robust research showing that the classification system proposed by Dr. Gunn is a treatment effect modifier. In the meantime, guidelines typically recommend triage of patients with low-back pain into 1 of 3 categories: nonspecific low-back pain (the vast majority), back pain potentially associated with radiculopathy or spinal stenosis, or back pain potentially associated with another specific spinal cause.5