Cost-Effectiveness of Dorsal Root Ganglion Stimulation or Spinal Cord Stimulation for Complex Regional Pain Syndrome.

OBJECTIVES: ACCURATE, a randomized controlled trial, compared safety and effectiveness of stimulation of the dorsal root ganglion (DRG) vs. conventional spinal cord stimulation (SCS) in complex regional pain syndrome (CRPS-I and II) of the lower extremities. This analysis compares cost-effectiveness of three modalities of treatment for CRPS, namely DRG stimulation, SCS, and comprehensive medical management (CMM). MATERIALS AND METHODS: The retrospective cost-utility analysis combined ACCURATE study data with claims data to compare cost-effectiveness between DRG stimulation, SCS, and CMM. Cost-effectiveness was evaluated using a Markov cohort model with ten-year time horizon from the U.S. payer perspective. Incremental cost-effectiveness ratio (ICER) was reported as cost in 2017 U.S. dollars per gain in quality-adjusted life years (QALYs). Willingness-to-pay thresholds of $50,000/QALY and $100,000/QALY were used to define highly cost-effective and cost-effective therapies. RESULTS: Both DRG and SCS provided an increase in QALYs (4.96 ± 1.54 and 4.58 ± 1.35 QALYs, respectively) and an increase in costs ($153,992 ± $36,651 and $128,269 ± $27,771, respectively) compared to CMM (3.58 ± 0.91 QALYs, $106,173 ± $27,005) over the ten-year model lifetime. Both DRG stimulation ($34,695 per QALY) and SCS ($22,084 per QALY) were cost-effective compared to CMM. In the base case, ICER for DRG v SCS was $68,095/QALY. CONCLUSIONS: DRG and SCS are cost-effective treatments for chronic pain secondary to CRPS-I and II compared to CMM. DRG accrued higher cost due to higher conversion from trial to permanent implant and shorter battery life, but DRG was the most beneficial therapy due to more patients receiving permanent implants and experiencing higher quality of life compared to SCS. New DRG technology has improved battery life, which we expect to make DRG more cost-effective compared to both CMM and SCS in the future.

The Impact of Tobacco Smoking on Spinal Cord Stimulation Effectiveness in Complex Regional Pain Syndrome Patients.

OBJECTIVES: We aim to investigate the correlation of smoking and spinal cord stimulation (SCS) effectiveness for pain relief in complex regional pain syndrome (CRPS) patients while controlling for possible confounding factors including opioid intake. MATERIALS AND METHODS: Following Institutional Review Board approval, a retrospective cohort study was performed by collecting data for all CRPS patients treated with SCS at Cleveland Clinic between 1998 and 2013. We divided patients into three groups based on their smoking status at the time of SCS device implant: Current smokers, former smokers, or nonsmokers. We used a linear mixed modeling to assess the association between smoking status and pain score at baseline and at 3, 6, and 12 months. We then used pairwise t-tests for post hoc comparisons of pain scores. RESULTS: Of the 420 CRPS patients treated with SCS implants, the reduction in pain score was highest among nonsmokers. Nonsmokers demonstrated a consistent and steady decrease in pain scores over time, whereas the current and former smoker cohorts showed an initial reduction in pain at three months compared to baseline which was not sustained to the 12-months benchmark. Nonetheless, former smokers continued to report slightly lower pain scores than current smokers, although not statistically significant. The baseline opioid consumption was least among nonsmokers (30 [0, 62] oral mg morphine sulfate equivalent). We also found a statistically significant association between time postimplant and reported pain score (χ2 = 508.88, p < 0.001). The overall mean pain score for all three cohorts was highest at baseline (7.6 ± 1.7) and showed a decrease at the 3, 6, and 12 months postimplant time points with mean score of 5.7 ± 2.0, 5.6 ± 2.3, and 5.4 ± 2.5, respectively. CONCLUSION: Tobacco cigarette smoking was associated with reduced SCS effectiveness for pain relief.

Choice of spinal cord stimulation versus targeted drug delivery in the management of chronic pain: a predictive formula for outcomes.

Contemporary nonmalignant pain treatment algorithms commence with conservative non-invasive strategies, later progressing from minimally invasive interventions to invasive techniques or implantable devices. The most commonly used implantable devices are spinal cord stimulation (SCS) systems or targeted drug delivery (TDD) devices. Historically, SCS had been considered in advance of TDD, positioning TDD behind SCS failures. Following Institutional Review Board approval, data were extracted from electronic medical records of patients who underwent SCS trial in the Department of Pain Management at Cleveland Clinic from 1994 to 2013. The sample size was analyzed in two cohorts: those who succeeded with SCS and those who failed SCS and consequently proceeded to TDD. Univariate and multivariate analyses were performed and a predictive formula for successful outcomes was created. 945 patients were included in the cohort of which 119 (12.6%) subjects achieved adequate pain relief with TDD after failure of SCS. Gender, age, depression and primary pain diagnosis were significantly different in this subgroup. Males were 52% less likely to experience pain relief with SCS. The odds of SCS success decreased as age increased by 6% per year. Patients with comorbid depression, interestingly, were 63% more likely to succeed with SCS. A logistic model was created to predict SCS success which was used to create a predictive formula. Older male patients diagnosed with spine-related pain were more likely to benefit from TDD than SCS. This observation potentially identifies a subgroup in whom consideration for TDD in advance of SCS failure could prove more efficient and cost effective. These retrospective findings warrant prospective comparative studies to validate this derived predictive formula.

The Impact of Tobacco Cigarette Smoking on Spinal Cord Stimulation Effectiveness in Chronic Spine-Related Pain Patients.

BACKGROUND AND OBJECTIVES: Despite the observation that select nicotine receptor agonists have analgesic effects, smokers report higher pain scores and more functional impairments than lifelong nonsmokers, attributable to exaggerated stress responses, receptor desensitization, and altered pharmacokinetics compounded by accelerated structural damage resulting from impaired bone healing, osteoporosis, and advancement of disk disease. We hypothesized that smoking diminishes the analgesic response to spinal cord stimulation (SCS) in patients with chronic spine-related pain conditions. METHODS: A retrospective cohort study was performed at Cleveland Clinic by collecting and assessing data of 213 patients who had been implanted with SCS for spine-pain indications. History of tobacco smoking was subcategorized into 3 categories: past (former smoker), present (current smoker), or those who had never previously smoked (lifelong nonsmokers), and a multivariable linear regression was run to measure the correlation, if any, between smoking status and numerical rating scale pain score. In addition, opioid consumption at baseline and 12-month follow-up, expressed in milligram oral morphine equivalents, was collected and compared. RESULTS: Adjusted for differences, at 1-year follow-up, current smokers (n = 62) reported numerical rating scale pain score of 7.0, which is 1.93 (P < 0.001) and 1.32 (P = 0.001) points higher than those of lifelong nonsmokers (n = 77) and former smokers (n = 74), respectively. Opioid intake was 2.4 times higher (P = 0.004) in smokers than in lifelong nonsmokers. CONCLUSIONS: Among our SCS-implanted sample, a positive correlation was observed between tobacco use and degree of pain reduction as early as 12 months postimplant; this was evident by the reported higher pain scores and opioid use in current smokers in comparison with former smokers and lifelong nonsmokers.