Background: Failed back surgery syndrome (FBSS) is a cause of significant morbidity for up to 40%
of patients following spine surgery, and is estimated to cost almost $20 billion. Treatment options for
these patients currently include conventional medical management (CMM), repeat operation, or spinal
cord stimulation (SCS). Much of the published data regarding cost effectiveness of SCS comprise smaller
scale randomized controlled trials (RCTs) rather than large databases capturing practices throughout
the US. SCS has been shown to have superior outcomes to CMM or repeat spinal operation in several
landmark studies, yet there are few large studies examining its long-term economic impact.
Objectives: This study compares health care utilization for SCS compared to other management in
patients with FBSS.
Study Design: Retrospective.
Setting: Inpatient and outpatient sample.
Methods: Patients with a history of FBSS from 2000 to 2012 were selected. We compared those who
received SCS to those who underwent conventional management. A longitudinal analysis was used to
model the value of log(cost) in each one year interval using a generalized estimating equations (GEE)
model to account for the correlation of the same patient’s cost in multiple years. Similarly, a Poisson
GEE model with the log link was applied to correlated count outcomes.
Results: We identified 122,827 FBSS patients. Of these, 5,328 underwent SCS implantation (4.34%)
and 117,499 underwent conventional management. Total annual costs decreased over time following
implantation of the SCS system, with follow-up analysis at 1, 3, 6, and 9 years. The longitudinal GEE
model demonstrated that placement of an SCS system was associated with an initial increase in total
costs at the time of implantation (cost ratio [CR]: 1.74; 95% confidence interval [CI]: 1.41, 2.15, P <
0.001), however there was a significant and sustained 68% decrease in cost in the year following SCS
placement (CR: 0.32; 95% CI: 0.24, 0.42, P < 0.001) compared to CMM. There was also an aggregate
time trend that for each additional year after SCS, cost decreased on average 40% percent annually
(CR: 0.60; 95% CI: 0.55, 0.65, P < 0.001), with follow-up up to 1, 3, 6, and 9 years post-procedure.
Limitations: Costs are not correlated with patient outcomes, patients are not stratified in terms of
complexity of prior back surgery, as well as inherent limitations of a retrospective analysis.
Conclusions: We found that from 2000 to 2012, only 4.3% of patients across the United States with
FBSS were treated with SCS. Long-term total annual costs for these patients were significantly reduced
compared to patients with conventional management. Although implantation of an SCS system results
in a short-term increase in costs at one year, the subsequent annual cumulative costs were significantly
decreased long-term in the following 9 years after implantation. This study combines the largest group
of FBSS patients studied to date along with the longest follow-up interval ever analyzed. Since SCS has
repeatedly been shown to have superior efficacy to CMM in randomized clinical trials, the current study
demonstrating improved long-term health economics at 1, 3, 6, and 9 years supports the long-term
cost utility of SCS in the treatment of FBSS patients.
Response to: Clinical Use, Quality of Life and Cost-Effectiveness of Spinal Cord Stimulation Used to Treat Failed Back Surgery Syndrome
