Specialty-Based Variations in Spinal Cord Stimulation Success Rates for Treatment of Chronic Pain.

OBJECTIVES: Spinal cord stimulation (SCS) has emerged as an appropriate modality of treatment for intractable chronic pain. The present study examines variations in SCS trial-to-permanent conversion rates based on provider types performing the procedure. MATERIALS AND METHODS: We designed a large, retrospective analysis using the Truven MarketScan data base analyzing adult SCS patients with provider information available, with or without IPG implantation from the years 2007-2012. Patients were categorized based on provider type performing the implantation including anesthesiologists, neurosurgeons, orthopedic surgeons, and physical medicine and rehabilitation (PM&R). Univariate and multivariate models identified factors associated with successful conversion. RESULTS: A total of 7667 unique instances of SCS implants were identified across five providers. Overall, 4842 (63.2%) of those receiving trials underwent permanent SCS system implantation. Anesthesiology performed the majority of implants (62.8%), followed by neurosurgery (22.0%), orthopedic surgery (10.2%), and PM&R (5.3%). Compared to anesthesiologists, both neurosurgeons (OR 10.99, 95% CI [9.11, 13.25]; p < 0.001) and orthopedic surgeons (OR 4.64, 95% CI [3.81, 5.65]; p < 0.001) had significantly higher conversion rates, while PM&R (OR 0.71, 95% CI [0.58, 0.87]; p = 0.001) had significantly lower. Percutaneous implants comprised 5473 (71.4%) of all implants. Neurosurgeons and orthopedic surgeons performed a significantly greater number of paddle implants among the different providers (p < 0.0001). Explant rates were similar across all cohorts analyzed (average 11.6%; p = 0.546). CONCLUSIONS: In this nationwide analysis, our results suggest that over a recent five-year period, conversion rates are highest when SCS trials are performed by neurosurgeons and orthopedic surgeons. The study has important implications for establishing uniform guidelines for training, patient selection, and education of physicians across multiple disciplines.

Prevalence of Specific Types of Pain Diagnoses in a Sample of United States Adults.

BACKGROUND: Patients with pain conditions place significant demands on health care services globally. Health economists have reported the annual economic cost of pain in the United States as high as $635 billion. A common challenge in treating patients suffering from chronic pain conditions is accurate diagnosis and treatment. OBJECTIVE: The aim of this study was to determine the modern-day prevalence of individual types of pain diagnoses in adults. STUDY DESIGN: Retrospective analysis of Truven MarketScan® Commercial and Medicare Supplemental database. SETTING: United States patient population with a pain diagnoses from 2000 to 2012. METHODS: Multivariate analysis was used to determine the individual prevalence of specific types of pain diagnoses over a 13-year period. PATIENTS: We grouped the 6,575,999 patients with ICD-9 pain diagnoses into pain groupings. RESULTS: We determined the prevalence of pain groupings as back pain (74.7%), chronic pain (10.4%), complex regional pain syndrome (1.2%), degenerative spine disease (63.6%), limb pain (50.0%), neuritis/radiculitis (52.8%), and post-laminectomy syndrome (14.8%). LIMITATIONS: Retrospective and non-randomized study, with a patient cohort that is weighted towards recent years and commercial insurance. Coding discrepancies that are recorded and collected for patients. CONCLUSIONS: The demographic differences and similarities within the subgroups highlighted the concept that pain diagnoses should be considered as separate, but related entities. The present study helps us to better understand the frequency of specific pain diagnoses, and directs future studies to appropriately focus on pain diagnoses based on prevalence. This will allow increased understanding of the variation in pain diagnoses and prevent over-generalization in studies examining pain patients to more accurately reflect the varied subtypes and their economic impact.Duke University Institutional Review Board Protocol: 00053624Key words: Pain diagnoses, CRPS, neuritis, radiculitis, limb pain, degenerative spine disease, back pain, chronic pain, post-laminectomy pain, prevalence, MarketScan.

The Volume-Outcome Effect: Impact on Trial-to-Permanent Conversion Rates in Spinal Cord Stimulation.

OBJECTIVES: Conversion rates from trial leads to permanent spinal cord stimulation (SCS) systems have important implications for healthcare resource utilization (HCRU) and pain management. We hypothesized that there is a volume-outcome effect, with chronic pain patients who visit high volume SCS implanters will have higher trial-to-permanent conversion rates. MATERIALS AND METHODS: We designed a large, retrospective analysis using the Truven MarketScan database analyzing adult SCS patients with provider information available, with or without IPG implantation from the years 2007 to 2012 was designed. Patients were divided into three provider-based groups: high (>25), medium (9-24), and low (3-8) volume providers. Univariate and multivariate models identified factors associated with successful conversion. RESULTS: A total of 17,850 unique trial implants were performed by 3028 providers. Of 13,879 patients with baseline data available, 8981 (64.7%) progressed to permanent SCS. Higher volume providers were associated with slightly higher conversion rates (65.9% vs. 63.3% low volume, p = 0.029), explant rates (9.2% vs. 7.7% medium volume, p = 0.026), younger age (52.0 ± 13.4 years vs. 53.0 ± 13.4 years, p = 0.0026), Medicare/Medicaid (47.8% vs. 35.0% low volume, p < 0.0001), Southern region (53.5% vs. 38.9% low volume, p < 0.0001), and higher Charlson comorbidity scores (1.0 [SD = 1.4], p = 0.0002). Multivariate regression results showed female gender (1.13 [95% CI: 1.05-1.22], p < 0.001) and high volume providers associated with higher odds of successful trial conversion (1.12 [95% CI: 1.02-1.22], p = 0.014). CONCLUSIONS: In this nationwide analysis, high volume providers achieved higher trial-to-permanent SCS conversion rates than lower volume providers. The study has implications for both training requirements and referral patterns to delineate minimum implant experience necessary for provider proficiency. Future studies may be useful to understand HCRU differences.