Parr et. al. performed a systematic review of the literature for caudal steroid injections with or without steroids for the management of various types of chronic lower back pain , including disc herniation or radiculitis, post lumbar laminectomy syndrome, chronic discogenic pain, and spinal stenosis, with or without lower extremity pain. 16 studies met the inclusion criteria set out by the researchers, which included 11 randomized trials and five non-randomized trials. The primary outcome measure was pain relief (including both short-term relief of pain for up to six months and long-term pain relief of longer than six months). Secondary outcome measures included functional status improvement, psychological status, return to work, and a reduction in narcotic medication usage.