Figure 1.

Sample selection flowchart.

Notes: *Patients with the following comorbidities were excluded: major depressive disorder, generalized anxiety disorder, epilepsy, diabetic peripheral neuropathic pain, and post-herpetic neuralgia.

Abbreviations: CLBP, chronic low back pain; SDI, Surveillance Data, Inc; SOC, standard of care; TCA tricyclic antidepressant.