Cost utility analysis of caudal epidural injections in the treatment of lumbar disc herniation, axial or discogenic low back pain, central spinal stenosis, and post lumbar surgery syndrome

Abstract

Background: In this era of escalating health care costs and the questionable effectiveness of multiple interventions, cost effectiveness or cost utility analysis has become the cornerstone of evidence-based medicine, and has an influence coverage decisions. Even though multiple cost effectiveness analysis studies have been performed over the years, extensive literature is lacking for interventional techniques. Cost utility analysis studies of epidural injections for managing chronic low back pain demonstrated highly variable results including a lack of cost utility in randomized trials and contrasting results in observational studies. There has not been any cost utility analysis studies of epidural injections in large randomized trials performed in interventional pain management settings. Objectives: To assess the cost utility of caudal epidural injections in managing chronic low back pain secondary to lumbar disc herniation, axial or discogenic low back pain, lumbar central spinal stenosis, and lumbar post surgery syndrome. Study Design: This analysis is based on 4 previously published randomized trials. Setting: A private, specialty referral interventional pain management center in the United States. Methods: Four randomized trials were conducted assessing the clinical effectiveness of caudal epidural injections with or without steroids for lumbar disc herniation, lumbar discogenic or axial low back pain, lumbar central spinal stenosis, and post surgery syndrome. A cost utility analysis was performed with direct payment data for a total of 480 patients over a period of 2 years from these 4 trials. Outcome included various measures with significant improvement defined as at least a 50% improvement in pain reduction and disability status. Results: The results of 4 randomized controlled trials of low back pain with 480 patients with a 2 year follow-up with the actual reimbursement data showed cost utility for one year of quality-adjusted life year (QALY) of $2,206 for disc herniation, $2,136 for axial or discogenic pain without disc herniation, $2,155 for central spinal stenosis, and $2,191 for post surgery syndrome. All patients showed significant improvement clinically and showed positive results in the cost utility analysis with an average cost per one year QALY of $2,172.50 for all patients and $1,966.03 for patients judged to be successful. The results of this assessment show a better cost utility or lower cost of managing chronic, intractable low back pain with caudal epidural injections at a QALY that is similar or lower in price than medical therapy only, physical therapy, manipulation, and surgery in most cases. Limitations: The limitations of this cost utility analysis include that it is a single center evaluation, even though 480 patients were included in the analysis. Further, only the costs of interventional procedures and physician visits were included. The benefits of returning to work were not assessed. Conclusion: This cost utility analysis of caudal epidural injections in the treatment of disc herniation, axial or discogenic low back pain, central spinal stenosis, and post surgery syndrome in the lumbar spine shows the clinical effectiveness and cost utility of these injections at less than $2,200 per one year of QALY.