Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society

Low back pain is the fifth most common reason for all physician visits in the United States (1, 2). Approximately one quarter of U.S. adults reported having low back pain lasting at least 1 whole day in the past 3 months (2), and 7.6% reported at least 1 episode of severe acute low back pain (see Glossary) within a 1-year period (3). Low back pain is also very costly: Total incremental direct health care costs attributable to low back pain in the U.S. were estimated at $26.3 billion in 1998 (4). In addition, indirect costs related to days lost from work are substantial, with approximately 2% of the U.S. work force compensated for back injuries each year (5). Many patients have self-limited episodes of acute low back pain and do not seek medical care (3). Among those who do seek medical care, pain, disability, and return to work typically improve rapidly in the first month (6). However, up to one third of patients report persistent back pain of at least moderate intensity 1 year after an acute episode, and 1 in 5 report substantial limitations in activity (7). Approximately 5% of the people with back pain disability account for 75% of the costs associated with low back pain (8). Many options are available for evaluation and management of low back pain. However, there has been little consensus, either within or between specialties, on appropriate clinical evaluation (9) and management (10) of low back pain. Numerous studies show unexplained, large variations in use of diagnostic tests and treatments (11, 12). Despite wide variations in practice, patients seem to experience broadly similar outcomes, although costs of care can differ substantially among and within specialties (13, 14). The purpose of this guideline is to present the available evidence for evaluation and management of acute and chronic low back pain (see Glossary) in primary care settings. The target audience for this guideline is all clinicians caring for patients with low (lumbar) back pain of any duration, either with or without leg pain. The target patient population is adults with acute and chronic low back pain not associated with major trauma. Children or adolescents with low back pain; pregnant women; and patients with low back pain from sources outside the back (nonspinal low back pain), fibromyalgia or other myofascial pain syndromes, and thoracic or cervical back pain are not included. These recommendations are based on a systematic evidence review summarized in 2 background papers by Chou and colleagues in this issue (15, 16) from an evidence report by the American Pain Society (17). The evidence report (17) discusses the evidence for the evaluation, and the 2 background papers (15, 16) summarize the evidence for management. Methods The literature search for this guideline included studies from MEDLINE (1966 through November 2006), the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and EMBASE. The literature search included all English-language articles reporting on randomized, controlled trials of nonpregnant adults (age >18 years) with low back pain (alone or with leg pain) of any duration that evaluated a target medication and reported at least 1 of the following outcomes: back-specific function, generic health status, pain, work disability, or patient satisfaction. The American College of Physicians (ACP) and the American Pain Society (APS) convened a multidisciplinary panel of experts to develop the key questions and scope used to guide the evidence report, review its results, and formulate recommendations. The background papers by Chou and colleagues (15, 16) provide details about the methods used for the systematic evidence review. This guideline grades its recommendations by using the ACP's clinical practice guidelines grading system, adapted from the classification developed by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) work group (Appendix Table 1) (18). The evidence in this guideline was first evaluated by the ACP/APS panel by using a system adopted from the U.S. Preventive Services Task Force for grading strength of evidence, estimating magnitude of benefits, and assigning summary ratings (Appendix Tables 2, 3, and 4) (19). The evidence was independently reviewed by the ACP's Clinical Efficacy Assessment Subcommittee. The ratings for individual low back pain interventions discussed in this guideline are summarized in Appendix Table 5 for acute low back pain (<4 weeks' duration) and in Appendix Table 6 for chronic/subacute low back pain (>4 weeks' duration). This guideline considered interventions to have proven benefits only when they were supported by at least fair-quality evidence and were associated with at least moderate benefits (or small benefits but no significant harms, costs, or burdens). Figures 1 and 2 present an accompanying algorithm. Appendix Table 1. The American College of Physicians Clinical Practice Guidelines Grading System Appendix Table 2. Methods for Grading the Strength of the Overall Evidence for an Intervention Appendix Table 3. Definitions for Estimating Magnitude of Effects Appendix Table 4. Recommendations and Summary Ratings Appendix Table 5. Level of Evidence and Summary Grades for Noninvasive Interventions in Patients with Acute Low Back Pain Appendix Table 6. Level of Evidence and Summary Grades for Noninvasive Interventions in Patients with Chronic or Subacute Low Back Pain Figure 1. Initial evaluation of low back pain ( LBP Figure 2. Management of low back pain ( LBP Recommendations: Evaluation of Low Back Pain Recommendation 1: Clinicians should conduct a focused history and physical examination to help place patients with low back pain into 1 of 3 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 (strong recommendation, moderate-quality evidence). More than 85% of patients who present to primary care have low back pain that cannot reliably be attributed to a specific disease or spinal abnormality (nonspecific low back pain [see Glossary]) (20). Attempts to identify specific anatomical sources of low back pain in such patients have not been validated in rigorous studies, and classification schemes frequently conflict with one another (21). Moreover, no evidence suggests that labeling most patients with low back pain by using specific anatomical diagnoses improves outcomes. In a minority of patients presenting for initial evaluation in a primary care setting, low back pain is caused by a specific disorder, such as cancer (approximately 0.7% of cases), compression fracture (4%), or spinal infection (0.01%) (22). Estimates for prevalence of ankylosing spondylitis in primary care patients range from 0.3% (22) to 5% (23). Spinal stenosis (see Glossary) and symptomatic herniated disc (see Glossary) are present in about 3% and 4% of patients, respectively. The cauda equina syndrome (see Glossary) is most commonly associated with massive midline disc herniation but is rare, with an estimated prevalence of 0.04% among patients with low back pain (24). A practical approach to assessment is to do a focused history and physical examination to determine the likelihood of specific underlying conditions and measure the presence and level of neurologic involvement (24, 25). Such an approach facilitates classification of patients into 1 of 3 broad categories: nonspecific low back pain, back pain potentially associated with radiculopathy (see Glossary) or spinal stenosis (suggested by the presence of sciatica [see Glossary] or pseudoclaudication), and back pain potentially associated with another specific spinal cause. The latter category includes the small proportion of patients with serious or progressive neurologic deficits or underlying conditions requiring prompt evaluation (such as tumor, infection, or the cauda equina syndrome), as well as patients with other conditions that may respond to specific treatments (such as ankylosing spondylitis or vertebral compression fracture). Diagnostic triage into 1 of these 3 categories helps guide subsequent decision making. Clinicians should inquire about the location of pain, frequency of symptoms, and duration of pain, as well as any history of previous symptoms, treatment, and response to treatment. The possibility of low back pain due to problems outside the back, such as pancreatitis, nephrolithiasis, or aortic aneurysm, or systemic illnesses, such as endocarditis or viral syndromes, should be considered. All patients should be evaluated for the presence of rapidly progressive or severe neurologic deficits, including motor deficits at more than 1 level, fecal incontinence, and bladder dysfunction. The most frequent finding in the cauda equina syndrome is urinary retention (90% sensitivity) (24). In patients without urinary retention, the probability of the cauda equina syndrome is approximately 1 in 10000. Clinicians should also ask about risk factors for cancer and infection. In a large, prospective study from a primary care setting, a history of cancer (positive likelihood ratio, 14.7), unexplained weight loss (positive likelihood ratio, 2.7), failure to improve after 1 month (positive likelihood ratio, 3.0), and age older than 50 years (positive likelihood ratio, 2.7) were each associated with a higher likelihood for cancer (26). The posttest probability of cancer in patients presenting with back pain increases from approximately 0.7% to 9% in patients with a history of cancer (not including nonmelanoma skin cancer). In patients with any 1 of the other 3 risk factors, the likelihood of cancer only increases to approximately 1.2% (26). Features predicting the presence of vertebral infection have not been well studied but