Electrodiagnostic (EDX) testing is a common diagnostic procedure used to evaluate patients with a wide variety of symptoms including pain, weakness, and numbness in a limb. Some of the most common disorders diagnosed by EDX testing include carpal tunnel syndrome, compressed spinal nerves (radiculopathies); muscle disorders (myopathies) and peripheral nerve injuries. In this project we examined the scope, quality, and outcomes for EDX service provision in the Veterans Health system and among elderly Medicare beneficiaries.
Specifically, our aims were: (1) to determine the extent of electrodiagnostic service provision by provider type in the Veterans Health Administration (VHA) and the Medicare program, (2) to examine variations and differences in electrodiagnostic (EDX) care provided to Veterans and elderly Medicare beneficiaries; and (3) to examine the relationship between EDX testing characteristics, adherence to EDX guidelines, and subsequent outcomes of care.
Electrodiagnostic care received by American Veterans and a nationally representative sample of Medicare beneficiaries was characterized according to: i) the professional providing services, ii) the extent of nerve conduction and EMG testing performed by different providers, and iii) the degree to which providers adhered to published Electrodiagnostic Medicine guidelines. Variations in testing were examined by selected characteristics of the provider -- most notably, physician or non-physician, specialty training, provider volume of EDX procedures, and region of the country -- as well as by key patient characteristics, including age, gender, race/ethnicity and number, type and severity of comorbidities, and referral reason. We considered a variety of outcomes, including (i) the diagnosis derived at the time of EDX testing, (ii) subsequent surgical and diagnostic interventions, and (iii) subsequent use of health care resources. Characteristics of EDX testing and adherence to guidelines were correlated with outcomes, adjusting for differences in providers' and patients' characteristics, using multivariate regression techniques.
Using VHA Inpatient and Outpatient data as well as Medicare claims, two cohorts were identified. The first cohort was comprised of beneficiaries undergoing EDX testing in 2004. The 12-month post-EDX care trajectory of this first cohort was examined for surgical and interventional procedures. For this first cohort, we examined referral reasons by looking at the symptom codes from three months preceding the electrodiagnostic study to determine the referral reason and involved body region - facilitating better interpretation of guideline compliance. The second cohort consisted of VHA and Medicare beneficiaries who had certain surgical interventions (e.g., carpal tunnel release, ulnar nerve decompression, tarsal tunnel surgery, cervical and lumbosacral laminectomy and discectomy, spinal stenosis decompression ) during 2006 and 2007.
The results of this study have provided unique insights into the provision of electrodiagnostic services in the VA healthsystem. These findings suggest high quality care by specialists in EDX medicine for veterans receiving these services for musculoskeletal and neurological conditions.
In the VA health system, there were 69,738 veterans undergoing electrodiagnostic evaluations during 2005. Those veterans who were seen for presumed low back symptoms totaled 7614 in 2005. Specialist physicians (physiatrists and neurologists) performed 90.1% of the procedures, with 5.5% done by other physician types, and 4.4% performed by non-physicians.
A total of 241,295 persons in the random Medicare sample data were identified as having received EDX testing in 2006. The majority of EDX tests were provided by specialists (52.6% neurologists and 19.7% PM&R). Nearly one in five Medicare beneficiaries received EDX care from non-specialists (21.8%) and the remainder received care from non-physician providers. This is in sharp contrast to the VA healthsystem, in which most veterans see a specialist for their electrodiagnostic testing. Geographic variations in provider care were more pronounced for CMS beneficiaries than for Veterans.
Focusing on the results for Veterans presenting with a complaint of low back symptoms (and no other referral complaint, N=7,614), the majority of electrodiagnostic encounters in the VA were guideline-adherent (61.3%). Both facility volume and provider type were also related to guideline adherence. Finally, the proportion of EDX encounters that were guideline-adherent also varied across VISNs.
In multivariate analyses, EDX encounters at low volume facilities were less likely to be guideline-adherent than those performed at medium (odds ratio [OR]: 1.88; 95% confidence interval [CI]: 1.59-2.23) or high volume (OR: 1.77, 95% CI: 1.54-2.03) facilities. EDX encounters were also less likely to be adherent if they were performed by a nonphysician when compared to either a specialist (OR: 1.53; 95% CI: 1.16-2.02) or nonspecialist (OR: 3.49; 95% CI: 2.01-5.03) physician.
Among the CMS population where there were greater proportions of non-physican providers, we found that specialists (neurologists and physiatrists) were quite concordant in identifying common conditions (polyneuropathy, lumbosacral radiculopathy, cervical radiculopathy, carpal tunnel syndrome, and ulnar neuropathy) in a cohort with diabetes. In contrast, other providers identified widely varying rates of disorders that were not accounted for by case mix adjustment.
The implications of these findings are important for healthcare policy makers in the CMS and VA healthcare systems. Physician providers gave more guideline-compliant care than non-physicians. In addition, the VA analyses clearly showed a compliance and facility volume relationship indicating that hospitals with high volume EDX services provide the most compliant care.
In addition, the VA health system utilizes specialists (Physiatrists and Neurologists) to a greater degree (90% of all studies) than the private sector or the Medicare beneficiaries receive in the United States.
Specialists are more guideline-compliant and concordant in rates of diagnoses indicating a common approach to these symptoms and that this care is consistent with published guidelines.
Implications for the VA healthsystem are that optimal care is rendered at high volume facilities and to the extent possible referral patterns should be in this direction. We received a follow-up pilot grant to examine coding for EDX studies. Our preliminary results suggest that specialists probably provide even more of the care than 90%, due to coding inaccuracies. This follow-up study should be informative to the VA regarding its coding system for EDX care.
- Sohn MW, Whittle J, Pezzin LE, Miao H, Dillingham TR. Electrodiagnostic consultation and identification of neuromuscular conditions in persons with diabetes. Muscle & Nerve. 2011 Jun 1; 43(6):812-7.
- Pezzin LP, Whittle JW, Sohn MS, Dillingham TR. Guideline Adherence in Electrodiagnostic Evaluation of Low Back Pain. Muscle & Nerve. 2008 Oct 1; 38(4):1350-1403.
- Dillingham TR, Pezzin LE. Rehabilitation setting and associated mortality and medical stability among persons with amputations. Archives of physical medicine and rehabilitation. 2008 Jun 1; 89(6):1038-45.
- Taylor CA, Braza D, Rice JB, Dillingham T. The incidence of peripheral nerve injury in extremity trauma. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2008 May 1; 87(5):381-5.
- Cannon DE, Dillingham TR, Miao H, Andary MT, Pezzin LE. Musculoskeletal disorders in referrals for suspected lumbosacral radiculopathy. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2007 Dec 1; 86(12):957-61.
- Cannon DE, Dillingham TR, Miao H, Andary MT, Pezzin LE. Musculoskeletal disorders in referrals for suspected cervical radiculopathy. Archives of physical medicine and rehabilitation. 2007 Oct 1; 88(10):1256-9.
- Dillingham TD. The REACTOR Program: A Cost-effective means of jump-starting PM&R research and developing cellular and molecular investigations. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2007 Jan 1; 86(Suppl 4):S122.
- Dillingham TR. Musculoskeletal rehabilitation: current understandings and future directions. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2007 Jan 1; 86(1 Suppl):S19-28.
- Benson JB, Del Toro DD, Miao HM, Dillingham TD, Brown KB. Rigid Versus Soft Dressings in the Postoperative Wound Management of Transtibial Amputations. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2006 Nov 1; 87(11):e31.
- Cupka, Zaza, Dillingham. Traumatic Nerve Injuries: Outcome Prediction Using Clinical and Electrodiagnostic Findings. Archives of physical medicine and rehabilitation. 2006 Nov 1; 87(11):e14.
- Taylor CT, Braza DB, Rice JR, Dillingham TD. The Prevalence of Peripheral Nerve Injury in Extremity Trauma. Archives of physical medicine and rehabilitation. 2006 Nov 1; 87(11):e16.
- Braza DB, Dillingham TD, Morzinski JM, Seagard JS, Sheehan KS. Development of a PM&R Faculty Promotion and Academic Progress Committee. American journal of physical medicine & rehabilitation / Association of Academic Physiatrists. 2006 Mar 1; 85(3):281.
- Ephraim PL, MacKenzie EJ, Wegener ST, Dillingham TR, Pezzin LE. Environmental barriers experienced by amputees: the Craig Hospital Inventory of Environmental Factors-Short Form. Archives of physical medicine and rehabilitation. 2006 Mar 1; 87(3):328-33.
- Dillingham TR. Electrodiagnostic Medicine II: clinical evaluation and findings. In: Braddom R, Buschbacher R, Chan R, Kowalske K, Laskowski E, Matthews D, Ragnarrson D, editors. Physical Medicine and Rehabilitation. 4th ed. Philadelphia, PA: WB Saunders; 2010.
- Dillingham TR, Pezzin LE, Whittle J, Sohn M. Electrodiagnostic Services in the United States; analysis of CMS Data. Paper presented at: American Association of Neuromuscular and Electrodiagnostic Medicine Annual Meeting; 2010 Oct 6; Québec City, Canada.