Magnetic Resonance Imaging of the Lumbar Spine

Transcription

1 Magnetic Resonance Imaging of the Lumbar Spine A targeted literature review was designed using relevant low back pain and MRI search terms. The search strategy was developed using Medical Subject Headings (MeSH) related to low back pain and MRI as well as other relevant text words identified in a primary literature scan. Results were limited to studies written in English and conducted in humans in the past ten years. The search was developed to answer the following evidence questions: 1. What is the evidence surrounding the utilization of lumbar spine MRI with and without antecedent therapy? 2. What is the evidence that utilization rates of lumbar spine MRI differ by patient characteristic? 3. What is the evidence that utilization rates of lumbar spine MRI differ by location? Profile of Evidence Brief Review and Discussion of Literature in National Quality Measures Clearinghouse, National Guideline Clearinghouse, PubMed, and Cochrane Databases National Quality Measures Clearinghouse Our search of the National Quality Measures Clearinghouse (NQMC), using the search terms low back pain and magnetic resonance imaging, returned two relevant documents that were unique to the NQMC. National Guideline Clearinghouse Our search of the National Guideline Clearinghouse (NGC), using the search terms low back pain and magnetic resonance imaging, returned six relevant documents that were unique to the NGC. PubMed A combination of search strategies including MeSH terms and text words was employed to identify the full range of literature for each of the key questions. The MeSH terms included: low back pain, magnetic resonance imaging, healthcare disparities, minority health, risk factors, age factors, comorbidity, poverty, social class, small-area analysis, and health services accessibility. Our searches in PubMed returned a total of 14 relevant studies. 1

2 Cochrane Review Databases For our review of the Cochrane Review Databases, including the Cochrane Database of Systematic Reviews, the Health Technology Assessment Database, and the National Health Service (NHS) Economic Evaluation Database, we used the following MeSH search terms: low back pain and magnetic resonance imaging. We were unable to identify any studies that were relevant to the key questions and unique to Cochrane (i.e., not included in the literature found in PubMed). Magnitude and/or Importance of the Problem Acute low back pain (LBP) with or without radiculopathy is one of the most common health problems in the United States. 1 It is estimated that the point prevalence of LBP in North America is 5.6 percent. 2 Most LBP follows injury or trauma to the back, but pain may also be caused by degenerative conditions such as arthritis or disc disease, osteoporosis or other bone diseases, viral infections, irritation to joints and discs, or congenital abnormalities in the spine. Obesity, smoking, weight gain during pregnancy, stress, poor physical condition, posture inappropriate for the activity being performed, and poor sleeping position also may contribute to LBP. Additionally, buildup of scar tissue from repeated injuries eventually weakens the back and can lead to more serious injury. Scar tissue created when the injured back heals itself may not have the strength or flexibility of normal tissue. 3 According to the American College of Radiology (ACR), uncomplicated acute LBP is a benign, self-limited condition that warrants no imaging studies. 4 A thorough medical history and physical examination can usually identify the cause of LBP. When LBP is not attributed to potentially serious spinal pathology or non-spinal pathology, there is a poor correlation of imaging findings with low back problems. 5,6,7,8 Despite consensus that there is little value in diagnostic imaging for acute LBP, the diagnosis is associated with significant practice variation for many imaging resources, including x-ray imaging, discography, computerized tomography (CT), magnetic resonance imaging (MRI), 1 Bradley WG for the Expert Panel on Neurologic Imaging. ACR appropriateness criteria: Low back pain. American Journal of Neuroradiology 2007;28(12): Loney PL, Stratford PW. The prevalence of low back pain in adults: a methodological review of the literature. Physical Therapy. 1999;79: Low back pain fact sheet. Rockville, MD: National Institute of Neurological Disorders and Stroke, Accessed May 7, 2009 at 4 Bradley WG for the Expert Panel on Neurologic Imaging. ACR appropriateness criteria: Low back pain. American Journal of Neuroradiology 2007;28(12): Borenstein DG, O Mara JW, Boden SD, et al. The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects : a seven-year follow-up study. Journal of Bone and Joint Surgery 2001;83-A(9): Carragee E, Alamin T, Cheng I, et al. Are first-time episodes of serious LBP associated with new MRI findings? Spine 2006;6(6): Epub 2006 Oct Jarvik JG, Hollingworth W, Martin B, et al. Rapid magnetic resonance imaging vs. radiographs for patients with low back pain: a randomized controlled trial. Journal of the American Medical Association 2003;289(21): Modic MT, Obuchowski NA, Ross JS, et al. Acute low back pain and radiculopathy: MR imaging findings and their prognostic role and effect on outcome. Radiology 2005;237(2):

3 electromyography, bone scans, thermography, and ultrasound imaging. 9 Such use has enormous cost implications largely due to the high cost of imaging studies and specialty referrals. 10 The cost of evaluating and treating acute LBP runs into billions of dollars annually, not including time lost from work. 11 Overview of Existing Measures Our search of the NQMC yielded two sets of quality measures relevant to LBP and MRI. In this section we provide an overview of our measure including the numerator, denominator, and exclusion criteria used to calculate the measure. We then provide an overview of the two quality measures identified through the NQMC. In cases of low back pain in which the condition is not debilitating in the long term, MRIs should not be performed. However, for patients with low back pain in addition to other indications of a more acute condition, an MRI may be appropriate. The table below (Table 1) lists several conditions for which a lumbar MRI should be performed, and the number of issued guidelines that specify the condition as MRI-appropriate. MRIs performed for these conditions are excluded from measures to look at low back pain MRI efficiency or overuse, as they are not regarded as procedures for simple low back pain. Rather, they are regarded as sensitive diagnostic procedures for patients with low back pain as well as other acute conditions. The middle column specifies whether the OP-8 MRI measure regards the condition as acute, should not be counted as a low back pain case, and should receive a lumbar MRI. The third column counts how many additional lumbar MRI guidelines also exclude the condition when measuring low back pain MRI use. Table 1 Comparison of Low Back Pain Imaging Efficiency Measure Exclusions Condition Excluded from OP-8 MRI Lumbar Spine for Low Back Pain Measure? Number of guidelines exclude (out of 4 guidelines) 12 Cancer Yes 4 Trauma Yes 4 IV drug abuse Yes 2 Neurologic impairment or Yes 4 deficit Human Immunodeficiency Yes 0 9 Ibid. 10 Rao JK, Kroenke K, Mihaliak KA, Eckert GJ, Weinberger M. Can guidelines impact the ordering of magnetic resonance imaging studies by primary care providers for low back pain? American Journal of Managed Care, 2002;8(1): Luo X, Pietrobon R, Sun SX, et al. Estimates and patterns of direct health care expenditures among individuals with back pain in the United States. Spine 2004;29: The four guidelines are: Use of Imaging Studies for Low Back Pain, NCQA; Adult Low Back Pain, ICSI; Practice Guideline for the Performance of MRI of the Adult Spine, American College of Radiology; Adult Low Back Pain, Institute for Clinical Systems Improvement. 3

4 Virus (HIV) Unspecified Immune Yes 1 Deficiencies Intraspinal abscess Yes 0 Unexplained fever No 2 Loss of bowel or bladder No 2 control Severe or unrelenting pain No 3 at rest or pain unresponsive to conservative therapy Ankylosing Spondylitis No 1 Unexplained weight loss No 1 Age greater than 70 No 1 Use of corticosteroids or No 1 osteoporosis Infection No 1 Prior lumbar surgery No 1 Our exclusion list was based on discussions with a technical expert panel and the National Quality Forum (NQF). This measure has been endorsed by the NQF and we have attempted to harmonize the specification of this measure with another NQF endorsed measure, Use of Imaging Studies for Low Back Pain, which was developed by the National Committee for Quality Assurance (NCQA). 13 Outpatient Imaging Efficiency Measure 8 MRI Lumbar Spine for Low Back Pain The purpose of this measure is to estimate the percentage of MRI lumbar spine studies which have claims-based indications of antecedent conservative therapy in patients diagnosed with LBP. The numerator of this measure is patients who had an MRI of the lumbar spine with a diagnosis of LBP without claims based evidence of antecedent conservative therapy. The denominator of this measure is all patients who had an MRI of the lumbar spine with a diagnosis of LBP. Patients with the following diagnoses were excluded from this measure: Cancer Trauma IV drug abuse Neurologic impairment Human immunodeficiency virus (HIV) Unspecified immune deficiencies Intraspinal Abscess 13 Detailed specifications of the NCQA measure are available in: National Committee for Quality Assurance. NQF-Endorsed National Voluntary Consensus Standards for Physician-Focused Ambulatory Care APPENDIX A NCQA Measure Technical Specifications April, 2008 V.7. 4

5 Operative, tumor, and acute injury cases Antecedent therapy may include injectable analgesic care, manual therapy or massage, chiropractic care, or a prior exam for low back pain evaluation. Patients with the operative, tumor, or acute injury cases listed above are excluded from the measure because it is generally agreed that those cases are more severe than low back pain and MRIs are useful for diagnosis. For full technical specifications of the measure please visit the QualityNet website: Relevant measures have been constructed previously by the National Committee for Quality Assurance and the Institute for Clinical Systems Improvement (ICSI). Summaries of the two existing measures follow. Use of imaging studies for low back pain: percentage of members with a primary diagnosis of low back pain who did not have an imaging study (plain x-ray, MRI, CT scan) within 28 days of the diagnosis. NCQA developed a measure to assess the percentage of patients with a primary diagnosis of LBP who did not have an imaging study. The measure is reported as an inverted rate where a higher score indicates appropriate treatment of LBP (i.e., the proportion for whom imaging studies did not occur). The denominator for this measure includes patients aged 18 to 50 with a negative diagnosis history and an outpatient or emergency department visit with a primary diagnosis of low back. The numerator for this measure includes patients without an imaging study conducted on the Index Episode Start Date (IESD) or in the 28 days following the IESD. This measure is calculated from administrative data using the following exclusions: 14 Cancer Trauma IV drug abuse Neurologic impairment Adult low back pain: percentage of patients with a diagnosis of back pain for whom the physician ordered imaging studies during the six weeks after pain onset, in the absence of red flag. ICSI developed a measure to assess the percentage of patients with a diagnosis of back pain for whom the physician ordered imaging studies during the six weeks after pain onset, in the absence of a red flag. The aim of this measure is to reduce unnecessary imaging in adult patients with LBP in the absence of red flag indicators or progressive symptoms. The denominator statement for this measure includes patients with acute LBP who present to clinic with LBP six weeks or less from onset of pain without red 14 National Committee for Quality Assurance (NCQA). HEDIS 2008: Healthcare Effectiveness Data & Information Set. Vol. 2, Technical Specifications. Washington (DC): National Committee for Quality Assurance (NCQA); 2007 Jul. 5

6 flag indicators. The numerator statement for this measure includes patients with acute LBP or sciatica receiving imaging studies: anterior-posterior (AP) or lateral (LAT) x-rays, CT scan, or MRI. This measure is calculated from administrative data and medical records. For the purposes of this measure, red flags are defined as: 15 Unrelenting night pain or pain at rest (increased incidence of clinically significant pathology) AP or LAT x-ray Fever above 38 degrees C (100.4 degrees F) for greater than 48 hours without obvious cause AP or LAT x-ray Progressive or new onset of neuromotor or sensory deficit MRI or CT Pain with distal numbness or leg weakness Loss of bowel or bladder control (retention or incontinence) Clinical suspicion of ankylosing spondylitis Significant trauma (accident or injury other than twisting or lifting injury unless other risk factors are present) History of or suspicion of cancer Overview of Existing Guidelines In addition to established quality measures for MRI of the lumbar spine for LBP, our search identified six practice guidelines and appropriateness criterion related to the use of MRI of the lumbar spine in NGC. American College of Radiology (2006) The 2006 American College of Radiology (ACR) Practice Guideline for the Performance of MRI of the Adult Spine advises that spine MRI should be performed only for a valid medical reason. The guideline further explains that while spinal MRI is one of the most sensitive diagnostic tests for detecting anatomic abnormalities of the spine and adjacent structures, findings may be misleading if not closely correlated with the clinical history, clinical examination, or physiologic tests. The guideline provides applications for MRI as a diagnostic tool for conditions such as neoplasms, infection, degenerative disease, spinal stenosis, intramedullary disease, and trauma. 16 In a related document, the ACR identifies its appropriateness criteria for low back pain. 17 The criteria indicate that MRI is particularly efficacious for detecting red flag diagnoses, particularly using the short tan inversion recovery (STIR) and fat-saturated T2 fast-spin-echo sequences. Red flags for the purposes of the ACR appropriateness criteria include: 15 Institute for Clinical Systems Improvement (ICSI). Adult low back pain. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2008 Nov. 66 p. 16 Practice Guideline for the Performance of MRI of the Adult Spine. Reston, VA: American College of Radiology, Accessed May 7, 2009 at 17 Bradley WG Jr, Seidenwurm DJ, Brunberg JA, Davis PC, DE La Paz RL, Dormont D, Hackney DB, Jordan JE, Karis JP, Mukherji SK, Turski PA, Wippold FJ, Zimmerman RD, McDermott MW, Sloan MA, Expert Panel on Neurologic Imaging. Low back pain. Reston, VA: American College of Radiology,

7 Recent significant trauma, or milder trauma, and age greater than 50; Unexplained weight loss; Unexplained fever; Immunosuppression; History of cancer; IV drug use; Prolonged use of corticosteroids or orsteoporosis; Age greater than 70; Focal neurologic deficit progressive or disabling symptoms; and Duration of pain greater than six weeks. In Table 2 below, we summarize the appropriateness rating of MRI use by LBP variation and other conditions. 18 Note that the appropriateness score ranges from 1 (least appropriate) to 9 (most appropriate). Table 2 American College of Radiology Appropriateness Ratings of MRI Use by LBP Variation Variant MRI lumbar spine without contrast appropriateness rating (out of a possible score of 9) MRI lumbar spine with and without contrast appropriateness rating (out of a possible score of 9) Uncomplicated, no red flags 2 2 Low velocity trauma, osteoporosis, and/or age 8 3 >70 years. Suspicion of cancer, infection, or 8 NA immunosuppression. Low back pain and/or radiculopathy, surgery or 8 5 intervention candidate Prior lumbar surgery 8 6 Cauda equina syndrome 9 8 The Institute for Clinical Systems Improvement (2008) The Institute for Clinical Systems Improvement (ICSI) released its guidelines on the treatment of adult low back pain in According to these guidelines, MRI is not useful in the early evaluation of low back pain or sciatica. The guidelines suggest appropriate consultation when a patient meets surgical referral criteria and the primary 18 Ibid. 7

8 care provider is uncertain whether an MRI or CT should be ordered. Further, the ICSI guidelines specify MRI is appropriate for the following indications: 19 Major or progressive neurologic deficit (e.g., foot drop or functionally limiting weakness such as hip flexion or knee extension) Cauda Equina Syndrome (loss of bowel or bladder control or saddle anesthesia) Progressively severe pain and debility despite conservative therapy Severe or incapacitating back or leg pain (e.g., requiring hospitalization, precluding walking, or significantly limiting the activities of daily living) Clinical or radiological suspicion of neoplasm (e.g., lytic or sclerotic lesion on plain radiographs, history of cancer, unexplained weight loss, or systemic symptoms) Clinical or radiological suspicion of infection (e.g., endplate destruction of plain radiographs, history of drug or alcohol abuse, or systemic symptoms) Trauma (fracture with neurologic deficit, compression fracture evaluation in elderly patients with question of underlying malignancy, characterization in anticipation of vertebroplasty/kyphoplasty, stress fracture or subacute spondylosis in a patient less than 18 years of age) Severe low back pain or radicular pain, unresponsive to conservative therapy, with indications for surgical intervention or therapeutic injection The American College of Physicians (ACP) and American Pain Society (APS) (2007) The ACP and APS released a joint set of guidelines in 2007 for evidence-based practice in the management of chronic spinal pain. The guidelines give the following four recommendations related to the evaluation and diagnosis of LBP: Clinicians should conduct a focused history and physical examination to help place patients with low back pain into one of three broad categories: nonspecific low back pain, back pain potentially associated with radiculopathy or spinal stenosis, or back pain potentially associated with another specific spinal cause. The history should include assessment of psychosocial risk factors, which predict risk for chronic disabling back pain. 2. Clinicians should not routinely obtain imaging or other diagnostic tests in patients with nonspecific low back pain. 3. Clinicians should perform diagnostic imaging and testing for patients with low back pain when severe or progressive neurologic deficits are present or when serious underlying conditions are suspected on the basis of history and physical examination. 4. Clinicians should evaluate patients with persistent low back pain and signs or symptoms of radiculopathy or spinal stenosis with magnetic resonance imaging 19 Institute for Clinical Systems Improvement (ICSI). Adult low back pain. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2008 Nov. 66 p. 20 Boswell MV, Trescot AM, Datta S, Schultz DM, Hansen HC, Abdi S, Sehgal N, Shah RV, Singh V, Benyamin RM, Patel VB, Buenaventura RM, Colson JD, Cordner HJ, Epter RS, Jasper JF, Dunbar EE, Atluri SL, Bowman RC, Deer TR, Swicegood JR, Staats PS, Smith HS, Burton AW, Kloth DS, Giordano J, Manchikanti L. Interventional techniques: evidence-based practice guidelines in the management of chronic spinal pain. Pain Physician 2007 Jan;10(1):

9 (preferred) or computed tomography only if they are potential candidates for surgery or epidural steroid injection (for suspected radiculopathy). Work Loss Data Institute (2008) A 2008 guideline released by the Work Loss Data Institute provides recommendations on return to work strategies for acute and chronic low back injuries in the lumbar and thoracic spine. Specifically, the guidelines recommend that physicians rule out red flags such as: Cauda Equina Syndrome Fracture, Compression fracture, Dislocation, Wound Cancer, Infection Dissecting/Ruptured Aortic Aneurysm Others (prostate problems, endometriosis/gynecological disorders, urinary tract infections, and renal pathology) For patients without radiculopathy, no imaging studies should be performed unless there has been significant trauma. For patients with lumbar sprain and lumbago, imaging studies are not recommended until at least the third interventional visit. Even then, imaging is not indicated in the absence of red flags unless the patient is still disabled. In patients with herniated disc, the first MRI to confirm extruded disk with nerve root displacement should not occur until at least the fourth interventional visit following more than a month of conservative therapy. In these instances MRI and CT are not indicated without obvious clinical level of nerve root dysfunction or clear radicular findings. 21 American College of Occupational and Environmental Medicine (2007) A final guideline released by the American College of Occupational and Environmental Medicine (ACOEM) in 2007 provides guidance on low back disorders. This guideline updates the 2004 release of these guidelines titled Low Back Complaints. In the 2007 release, ACOEM advises the initial assessment of patients with low back problems focusing on detecting red flags through observation and medical history. In the absence of red flags, imaging and other tests are not recommended in the first 4 to 6 weeks of low back symptoms as they almost never result in a meaningful change in clinical management. Instead, ACOEM recommends primary care management of low back problems conservatively through the use of nonprescription medication or an appropriately selected nonsteroidal anti-inflammatory drug (NSAID), appropriate adjustment of physical activity if needed, and the use of thermal modalities such as heat and/or cryotherapies. The guidelines further warn that abnormal findings on x-rays, MRIs, and other diagnostic tests are so common that they become normal by age 40, and by age 60 will be encountered in 80 percent of patients. ACOEM provides a summary of 21 Work Loss Data Institute. Low back - lumbar & thoracic (acute & chronic). Corpus Christi (TX): Work Loss Data Institute; p. 9

10 recommendations for evaluating and managing low back disorders. Within these, MRI is recommended for the following indications: Acute LBP during first 6 weeks if red flags are present (red flags defined as indications of potentially serious disease, such as fever or major trauma). Subacute or chronic radicular pain syndromes lasting at least 4 to 6 weeks As an option for select chronic LBP Conversely, MRI is not recommended for acute radicular pain syndromes in first 6 weeks, regardless of signs of neurological impingement, unless severe and not trending towards improvement. 22 Evidence Questions Key Question 1: What is the evidence surrounding the utilization of Lumbar Spine MRI with and without antecedent therapy? Our search returned 13 studies that provided information regarding the use of lumbar spine MRI with and without antecedent therapy. Of these studies there were one systematic review, two randomized control trials (RCTs), seven prospective observational studies, and three retrospective observational studies. One of the 13 studies relevant to the first key question aimed to evaluate the literature surrounding the utilization of advanced spinal imaging and low back pain through a systematic review. This study analyzed RCTs that compared immediate lumbar imaging (i.e., radiography, MRI, or CT) versus usual clinical care without immediate imaging for low-back pain. Included trials reported pain or function primary outcomes, quality of life, mental health, overall patient-reported improvement based on various scales, and patient satisfaction in care received. Following a meta-analysis of the results of these trials, the study concluded that lumbar imaging for low-back pain without indications of serious underlying conditions does not improve clinical outcomes. The authors further recommended that clinicians should refrain from routine, immediate lumbar imaging in patients with acute or subacute low-back pain and without features suggesting a serious underlying condition. 23 Five studies measured the correlation between abnormal findings on an MRI and the development of back pain including four prospective observational studies and one retrospective observational study. The majority of these studies found no or limited correlation between MRI findings and incidence of LBP. For example, in one study (n=67), researchers investigated whether findings of abnormalities in MRI scans are predictive of back pain in asymptomatic patients. This study concluded that findings of 22 Hegmann KT, ed. Low back disorders. In: Glass LS, editor(s). Occupational medicine practice guidelines: evaluation and management of common health problems and functional recovery in workers. 2nd ed. Elk Grove Village (IL): American College of Occupational and Environmental Medicine (ACOEM); p Chou R, Fu R, Carrino JA, Deyo RA. Imaging strategies for low-back pain: systematic review and metaanalysis. The Lancet 2009;373(9662):

11 abnormalities were not predictive of the development of LBP. Further, individuals with the longest duration of LBP did not have the greatest degree of anatomic abnormality on the MRI. 24 Similarly, two studies (n=148, n=200) of patients without baseline LBP were unable to identify physiologic predictors of LBP based on MRI findings at a 3- and 5- year follow-up, respectively. 25,26 Another study (n=148) aimed to calculate the prevalence of abnormal MRI findings among persons with current LBP or sciatica and to determine which findings are related to age or previous back symptoms. This study concluded that abnormal MRI findings are frequently found in subjects without low back pain and MRI studies for LBP are of limited diagnostic use. 27 Conversely, one study (n=412) investigating the prevalence of abnormal lumbar spine MRI findings and their association with LBP found most degenerative disc abnormalities evident in the MRI findings were moderately associated with LBP. 28 Two studies looked into the value of lumbar spine MRI in planning conservative care, including one RCT and one prospective observational study. Both of these studies found minimal to no value in incorporating MRI into evaluation for LBP management. The objective of the RCT (n=782) was to establish whether the early use of sophisticated imaging techniques influences the clinical management and outcome of patients with LBP and whether it is cost-effective in the United Kingdom. This study randomized its participants to early imaging or standard imaging. Ninety percent of patients received imaging in the early imaging group while only 30 percent received MRI or CT in the standard group. Both groups showed improvement in Aberdeen Lower Back Pain (ALBP), SF-36 and the EuroQol instrument (EQ-5D) scores at 24 months, and scores for the early imaging group showed small but positive differences over the standard group scores. One significant difference between the two groups was the cost of care due to the cost of imaging. 29 An additional study (n=246) in this category prospectively examined MRI findings, prognostic role of the findings, and effect of diagnostic information on outcomes in patients with acute LBP or radiculopathy. Using outcome measures such as Roland function scoring, visual pain analog, SF-36, self-efficacy scoring, and a fear avoidance measures, investigators found that in typical patients with LBP or radiculopathy, MRI does not appear to have measurable value in terms of planning 24 Borenstein DG, O Mara JW, Boden SD, et al. The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects: a seven-year follow-up study. American Journal of Bone and Joint Surgery 2001;83-A(9): Jarvik JG, Hollingworth W, Martin B, et al. Rapid magnetic resonance imaging vs. radiographs for patients with low back pain: a randomized controlled trial. Journal of the American Medical Association 2003;289(21): Carragee E, Alamin T, Cheng I, et al. Are first-time episodes of serious LBP associated with new MRI findings? Spine 2006;6(6): Epub 2006 Oct Jarvik JJ, Hollingworth W, Heagerty P, Haynor DR, Deyo RA. The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data. Spine 2001;26(10): Kjaer P, Leboeuf-Yde C, Korsholm L, Sorensen JS, Bendix T. Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women. Spine 2005;30(10): Gilbert FJ, Grant AM, Gillan MG, et al. Low back pain: influence of early MR imaging or CT on treatment and outcome--multicenter randomized trial. Radiology 2004; 231(2): Epub 2004 Mar 18. and Gilbert FJ, Grant AM, Gillan MG, et al. Does early imaging influence management and improve outcome in patients with low back pain? A pragmatic randomised controlled trial. Health Technology Assessment 2004;8(17):iii,

12 conservative care. 30 One prospective observational and one retrospective observational study investigated trends in lumbar spine MRI use over time. Both of these studies found increasing rates of MRI utilization. In a study (n=540) to compare primary care provider (PCP) use of lumbar spine MRI studies and surgical referrals for patients with LBP before and after dissemination of Agency for Healthcare Policy and Research LBP Guidelines, investigators found that while PCPs more frequently ordered a surgery consult in 1994 than in 1996, orders for MRI did not decrease after education on the guidelines. 31 Similarly, in a study (n=not specified) to assess changes in prevalence and Medicareassociated charges for non-invasive/minimally invasive evaluation and treatment of nonspecific LBP, there was a 5.5 percent increase in LBP patients and 33.2 percent increase in charges from 2000 to A final retrospective observational study (n=35,039) analyzed Medicare claims from and for fee-for-service Medicare beneficiaries with acute LBP. This study found that of the beneficiaries with LBP, 28.8 percent of beneficiaries underwent imaging within 28 days and an additional 4.6 percent underwent imaging between 28 and 180 days. Further, among patients who received imaging, 88.2 percent received radiography, while 11.8 percent received CT/MRI as their initial study. 33 Key Question 2: What is the evidence that utilization rates of Lumbar Spine MRI differ by patient characteristic? Our search returned six studies that provided information regarding characteristics of the patients receiving lumbar spine MRI. Five of these studies are prospective observational studies and one is a retrospective observational study. Of the relevant studies, one considers age factors alone, two investigate specific patient characteristics alone, two evaluate both, and one considered age, race, and patient demographics. 34,35 Of the four studies that consider age as a patient characteristic, none of the studies provide outcomes differentiated by age; however, they all investigate a specific age cohort or stratify their intervention groups by age. For example, one study (n=148) observed an age-stratified sample of patients without LBP in the past 4 months to determine the prevalence of MRI findings in the lumbar spine among persons with 30 Modic MT, Obuchowski NA, Ross JS, et al. Acute low back pain and radiculopathy: MR imaging findings and their prognostic role and effect on outcome. Radiology 2005;237(2): Rao JK, Kroenke K, Mihaliak KA, Eckert GJ, Weinberger M. Can guidelines impact the ordering of magnetic resonance imaging studies by primary care providers for low back pain? American Journal of Managed Care 2002;8(1): Weiner DK, Kim YS, Bonino P, Wang T. Low back pain in older adults: are we utilizing healthcare resources wisely? Pain Medicine 2006;7(2): Pham HH, Landon BE, Reschovsky JD, Wu B, Schrag D. Rapidity and modality of imaging for acute low back pain in elderly patients. Archives of Internal Medicine 2009;169(10): McNally EG, Wilson DJ, Ostlere SJ. Limited magnetic resonance imaging in low back pain instead of plain radiographs: experience with first 1000 cases. Clinical Radiology 2005;56(11): Carragee E, Alamin T, Cheng I, et al. Are first-time episodes of serious LBP associated with new MRI findings? Spine 2006;6(6): Epub 2006 Oct

13 current LBP or sciatica and to examine which findings are related to age or previous back symptoms. This study found that MRI had limited diagnostic use regardless of age. 36 Another study (n=412) focused specifically on lumbar spine MRI in 40-year olds. This study concluded that for this age cohort, most degenerative disc abnormalities were moderately associated with LBP. 37 A similar study (n=not specified) investigated MRI utilization appropriateness in older adults with chronic LBP. The study found that in the cohort of older adults over the age of 70 included in this study, none had red flags yet 61 percent had undergone MRIs. 38 Four prospective observational studies evaluated the impact of specific patient characteristics on the usefulness of lumbar spine MRI. Of these four studies, two also incorporated age as a factor for consideration. In these two studies, one (n=148) examined individuals without LBP to determine if MRI findings could predict future LBP and the other (n=412) examined patients with abnormal MRI findings to determine if there was a correlation with the diagnosis of LBP. The study of patients without LBP found that there was no correlation between abnormal MRI findings and future LBP while the study of patients with abnormal MRI findings concluded most degenerative disc abnormalities were moderately associated with LBP. 39, 40 Of the two studies that only investigated specific patient characteristics, one (n=200) focused on a patient population with first-time episodes of serious LBP and the other (n=1042) enrolled patients with LBP unresponsive to conservative treatment to determine if there were underlying comorbidities undetected by clinical examination and medical history. In the study of first-time serious LBP, investigators found subjects having multiple MRIs were more likely to have had chronic pain at baseline, to smoke, to have baseline psychological distress, and to have previous disputed compensation claims. 41 In patients with LBP unresponsive to conservative treatment, 20 percent were found to have malignancy, infection, vertebral fracture, spondylitis, pars defects, or cord tumors through MRI-assisted diagnosis. This study found an added value of MRI for patients unresponsive to conservative treatment. 42 A final study (n=35,039) analyzed Medicare claims data for fee-for-service Medicare beneficiaries with acute LBP, considering patient age, race, gender, comorbidity, and 36 Jarvik JJ, Hollingworth W, Heagerty P, Haynor DR, Deyo RA. The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data. Spine 2001;26(10): Kjaer P, Leboeuf-Yde C, Korsholm L, Sorensen JS, Bendix T. Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women. Spine 2005;30(10): Weiner DK, Kim YS, Bonino P, Wang T. Low back pain in older adults: are we utilizing healthcare resources wisely? Pain Medicine 2006;7(2): Jarvik JJ, Hollingworth W, Heagerty P, Haynor DR, Deyo RA. The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data. Spine 2001;26(10): Kjaer P, Leboeuf-Yde C, Korsholm L, Sorensen JS, Bendix T. Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women. Spine 2005;30(10): Carragee E, Alamin T, Cheng I, et al. Are first-time episodes of serious LBP associated with new MRI findings? Spine 2006;6(6): Epub 2006 Oct McNally EG, Wilson DJ, Ostlere SJ. Limited magnetic resonance imaging in low back pain instead of plain radiographs: experience with first 1000 cases. Clinical Radiology 2005;56(11):

14 demographics. 43 The table below (Table 3) provides a summary of the findings. Table 3 Use of Imaging of Low Back Pain in the Elderly Population Age Any CT/MRI (%) Radiography Only (%) No Imaging Within 180 Days (%) > Gender Female Male Race White Black Other Charlson Comorbidity Index No Comorbidities Comorbidity > 2 Comorbidities Median Household Income in Zip Code Above County Median Below County Median This study concluded that the rapidity and modality of imaging for LBP is associated with patient and physician characteristics but the directionality of associations with desirable care processes is opposite of associations for measures targeting underuse. Metrics that encompass overuse may suggest new areas of focus for quality improvement, such as imaging efficiency measures. 44 Key Question 3: What is the evidence that utilization rates of Lumbar Spine MRI differ by location? Our search returned one retrospective observational study that investigated geographic variation in the use of lumbar spine MRI. This study used a random five percent sample of Medicare s National Claims History Part B files for 1996 and 1997 to determine 43 Pham HH, Landon BE, Reschovsky JD, Wu B, Schrag D. Rapidity and modality of imaging for acute low back pain in elderly patients. Archives of Internal Medicine 2009;169(10): Ibid. 14

15 procedure rates across 306 Hospital Referral Regions and then subsequently analyzed the association between spinal imaging and spine surgery using linear regression. The analysis found that rates of advanced spinal imaging (i.e., CT and MRI combined) varied 5.5-fold across geographic areas. Further, areas with higher rates of MRI had higher rates of spine surgery overall and spinal stenosis surgery specifically; however, a simulation model showed that MRIs obtained in the patients undergoing surgery accounted for only a small part of the correlation between MRI and total spine surgery rates. The rates of advanced spinal imaging accounted for 22 percent of the variability in overall spine surgery rates and 14 percent of the variability in lumbar stenosis surgery rates. The study concluded that a significant proportion of the variation in rates of spine surgery can be explained by differences in the rates of advanced spinal imaging. While the indications for advanced spinal imaging are not firmly agreed on, and the appropriateness of many of these imaging studies has been questioned, improved consensus on the use and interpretation of advanced spinal imaging studies could have an important effect on variation in spine surgery rates Lurie JD, Mirkmeyer NJ, Weinstein JN. Rates of advanced spinal imaging and spine surgery. Spine 2003;28(6):

16 Glossary of Commonly Used Terms ALBP score: Aberdeen Lower Back Pain score, derived from a condition-specific questionnaire that assesses lower back pain across several dimensions. The ALBP asks questions about pain, physical impairment, and functional disability. Scores range from 0 for the least disabled to 100 for the most disabled. 46 Charlson Comorbidity Index: predicts the 1 year mortality for a patient who may have a range of co-morbid conditions. Each condition is assigned with a score of 1,2,3 or 6 depending on the risk of dying associated with this condition. Then the scores are summed up and given a total score which predicts mortality. 47 Degenerative disease: a disease in which the function or structure of the affected tissues or organs changes for the worse over time. Osteoarthritis, osteoporosis, and Alzheimer disease are examples. 48 EQ-5D: EuroQol instrument, a generic health-related quality of life measure developed by a group of Europe-based researchers. The descriptive system consists of five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. 49 Infection: invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system. 50 Intramedullary disease: a lesion on the spinal cord. It may be of several different etiologies: demyelinating, neoplastic, degernative, inflammatory, congenital, etc. 51 Neoplasm: an abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Neoplasms may be benign (not cancer) or malignant (cancer). Otherwise known as a tumor Gilbert FJ, Grant AM, Gillan MG, et al. Low back pain: influence of early MR imaging or CT on treatment and outcome--multicenter randomized trial. Radiology 2004; 231(2): Epub 2004 Mar Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. Journal of Chronic Diseases, 1987;40(5): National Cancer Institute Dictionary of Cancer Terms. Accessed on May 27, 2009 at 49 U.S. Valuation of the EuroQol EQ-5D Health States. December Agency for Healthcare Research and Quality, Rockville, MD. Accessed May 28, 2009, at 50 National Cancer Institute Dictionary of Cancer Terms. Accessed on May 27, 2009 at 51 Practice Guideline for the Performance of MRI of the Adult Spine. Reston, VA: American College of Radiology, Accessed May 7, 2009 at 52 National Cancer Institute Dictionary of Cancer Terms. Accessed on May 27, 2009 at 16

17 PCP: primary care provider QALY: Quality-Adjusted Life-Year. A unit of health care outcomes that adjusts gains (or losses) in years of life subsequent to a health care intervention by the quality of life during those years. QALYs can provide a common unit for comparing cost-utility across different interventions and health problems. 53 Radiculopathy: pain radiating down the legs SF-36: a multi-purpose, short-form health survey with 36 questions. It yields an 8-scale profile of functional health and well-being scores as well as psychometrically-based physical and mental health summary measures and a preference-based health utility index. It is a generic measure, as opposed to one that targets a specific age, disease, or treatment group. Accordingly, the SF-36 has proven useful in surveys of general and specific populations, comparing the relative burden of diseases, and in differentiating the health benefits produced by a wide range of different treatments. 54 Spinal stenosis: narrowing in the upper or lower back that puts pressure on the spinal cord or the nerves that branch out from the compressed areas. It can result in cramping, pain or numbness in legs, back, neck, shoulders, or arms; loss of sensation in the extremities; and sometimes bladder or bowel problems. Spinal stenosis is most commonly caused by osteoarthritis bone damage. 55 Trauma: injury to the body, or an event that causes long-lasting mental or emotional damage. 56 This material provided by FMQAI, the Medicare Quality Improvement Organization for Florida, an agency of the U.S. Department of Health and Human Services, was prepared by The Lewin Group, Imaging measure writers under contract with the Centers for Medicare & Medicaid Services (CMS). The contents presented do not necessarily reflect CMS policy. FL2009HODT8A National Information Center on Health Services Research and Health Care Technology. HTA 101: Glossary. Accessed May 28, 2009 at 54 Ware, John E. SF-36 Health Survey Update. Accessed May 28, 2009, at 36.org/tools/SF36.shtml. 55 Mayo Clinic. Spinal Stenosis. Updated March 11, Accessed May 28, 2009, at 56 National Cancer Institute Dictionary of Cancer Terms. Accessed on May 27, 2009 at 17