By Michael Rubin, MD

Professor of Clinical Neurology, Weill Cornell Medical College

Dr. Rubin reports he is a consultant for Merck Sharp & Dohme Corp.

SYNOPSIS: In a retrospective review of patients treated for low back pain and lumbar radiculopathy at the Cleveland Clinic, at three- and six-month follow-up, epidural steroid injections were no better than conservative therapies in quality of life measures or overall cost of medical care.

SOURCE: Pennington Z, Swanson MA, Lubelski D, et al. Comparing the short-term cost-effectiveness of epidural steroid injections and medical management alone for discogenic lumbar radiculopathy. Clin Neurol Neurosurg 2020; Jan. 13. [Online ahead of print].

Among the 85% of the population who will experience low back pain at some point in their lives, it will be nonspecific in 85% and not attributable to any specific pathology. Return to work will occur within a month, with further improvement by three months, after which pain and disability levels will remain constant. Nonsurgical treatment modalities, often recommended despite the absence of clinical evidence of benefit, include intradiscal glucocorticoid injection, local or trigger point injection using a local anesthetic with or without a corticosteroid, facet joint injection and medial branch block, sacroiliac joint injection, and electrodermal and radiofrequency denervation. Despite the possibility of serious adverse events, including blindness, stroke, paralysis, and death, epidural steroid injection (ESI) is used for nonspecific low back pain, spinal stenosis, and radiculopathy, with the best benefit, albeit short-term, demonstrated for radiculopathy due to disc herniation. Is ESI cost-effective and does it produce improvement in long-term quality of life (QOL)?

Pennington et al undertook a retrospective electronic medical record (EMR) review of patients seen between 2009-2015 for low back pain and lumbar radiculopathy at the Cleveland Clinic Center for Spine Health. Exclusionary criteria included prior lumbar spine surgery or non-epidural steroid injection, such as facet-joint, medial branch block, or caudal injections; evidence of other neurologic disease, such as multiple sclerosis; non-spondylotic causes of radicular pain, such as infection or tumor; or concomitant workers compensation claim. QOL scores included the Pain Disability Questionnaire (PDQ), the Patient Health Questionnaire-9 (PHQ-9), and the EuroQOL-5 Dimensions (EQ-5D), all obtained via the institutional Knowledge Program, an integral component of the EMR in which all patients had been enrolled prospectively. Direct costs were defined as all hospital charges to the patient undergoing the procedure, with Medicare national payment amounts used to estimate all direct cost data, and Diagnosis Related Group (DRG) and CPT code-associated costs recorded in the year of surgery adjusted for inflation to 2015 dollars. Pharmaceutical costs were estimated from the 2007 Red Book for Medications. Statistical analysis used the mean and standard deviation for continuous variables and proportions for categorical or dichotomous variables, student’s t-test for continuous variables, and Fisher’s exact tests, with 0.05 used as the threshold for statistical significance.

Among 810 patients screened, 141 met inclusion criteria, of which 52 underwent conservative management alone, and 89 received, in addition, ESI. Overall, 61% were male, average age was 68.5 years, mean body mass index was 29.7 kg.m², and the most common diagnoses were spinal stenosis (41.8%), spondylosis (24.1%), and degenerative disc disease (21.3%). At three months, relative to baseline, both groups showed significant improvements on only the EQ-5D but not on any of the other patient-related outcomes (PROs), and no differences were found between cohorts with respect to any of the PROs. At six-month follow-up, no significant differences were detected on any of the collected PROs between groups or within groups, and sub-analysis of the ESI group failed to demonstrate any significant differences in the three- or six-month outcomes between patients receiving transforaminal ESI and those receiving interlaminar ESI. At three months, total costs incurred by the ESI cohort patients were $2,190.39, compared to $1,772.22 for the conservative cohort, a nonsignificant difference. At three and six months, no significant differences were noted between groups in terms of direct, indirect, or total costs. The number of missed days was similar in both groups. Significant increases in quality-adjusted life years (QALY) for both the ESI and conservative groups were identified, but no differences were noted between the two groups. All QALY improvement was lost by the six-month follow-up relative to baseline. The investigators concluded that ESI is not cost-effective at either the three- or six-month follow-up period, it is not better than medical management at three months, and neither ESI nor medical management provides significant QOL improvement over baseline at six months.

COMMENTARY

Chronic low back pain persisting for more than 12 weeks is best treated conservatively. For patients without disabling symptoms, participation in an independent or structured regular exercise program is central. When symptoms are disabling, the goals of care comprise pain management, functional improvement, and maximizing coping skills, for which multiple modalities, including exercise therapy, psychological and/or mind-body interventions, and pharmacologic therapy often are required.