In 2009-10, the NIH Pain Consortium convened two workshops on chronic low back pain, noting that researchers use varied inclusion criteria, definitions, baseline assessments, and outcome measures. Such variation impedes our ability to compare studies, replicate findings, pool data, resolve conflicts, and achieve consensus. It was recommended that NIH establish research standards on chronic low back pain (cLBP).
The Pain Consortium subsequently assembled a Task Force on Research Standards (RTF) for cLBP. The goal was to recommend more consistent ways of classifying patients and reporting research results. The NIH will require all grant applications to apply the standards to proposed study designs that deal with cLBP. The Task Force just published its report in the Journal of Pain[1] with simultaneous publication in Spine, The Spine Journal, Clinical Journal of Pain, and pending in the European Spine Journal.
Background: Chronic low back pain is common and has a major societal impact. Despite rapidly increasing use of medications, injections, and surgery, functional disability has increased in recent decades.[2] Many patients who have procedures to correct putative causes continue to have pain. Further, we often cannot identify mechanisms to explain the major negative impact cLBP has on many patients. Such cLBP is often termed nonspecific, idiopathic, or mechanical, and may in fact be due to varied and multiple biologic and behavioral etiologies.
Approach: The Task Force had Co-chairs with complementary expertise in back pain research and in development of research standards, and 14 additional members with varied scientific and clinical expertise. The group evolved a three-stage work plan, each with a 2-day meeting and intervening literature review. Between meetings, the co-chairs surveyed members regarding key elements. These principles emerged:
- The process should be evidence-based and use a biopsychosocial model of chronic pain.
- Data should be useful for patients with degenerative disorders (e.g., herniated disc, lumbar stenosis) as well as those without clear anatomical causes.
- Patients with no clear anatomical cause should not be assumed to have “psychogenic” pain.
- Classifying cLBP by impact is more feasible and potentially useful than classifying solely by pathophysiology. “Impact” includes pain intensity, interference, and physical function.
- A brief minimal uniform dataset should be reported in all studies of chronic back pain.
- The dataset should be relevant for population, observational, and interventional research.
- An investigator could substitute more detailed and precise measures for a particular domain but should report all domains of the minimal dataset.
Recommendations:
- Definition of cLBP: A patient who reports pain on at least half the days in the past 6 months; that is, a total of at least 3 months’ worth of pain days in the last 6 months.
- Classification of cLBP by Impact: “Impact” was calculated with the Patient Reported Outcomes Measurement Information System (PROMIS) short form and used pain intensity, pain interference with normal activities, and functional status.
- Minimal Dataset: Key elements were demographics, involvement in workers’ compensation, work status, education, comorbidity, and previous treatment. Self-report domains were pain intensity, pain interference, physical function, depression, sleep disturbance, and catastrophizing. Short form PROMIS measures were recommended.
- Outcome Measures: The RTF did not recommend specific outcome measures, but it did recommend reporting a “responder” analysis in addition to reporting group means of outcome measures.
- Recommendations for Research on the Proposed Standards: The RTF recommended research to improve prognostic stratification; test composite outcome measures; assess patient stakeholders’ views of relevant outcomes; and further evaluate psychometric properties of the minimal dataset.
Conclusion: The RTF believes these recommendations will advance the field, help resolve controversies, and facilitate future research on cLBP. We expect the recommendations will be dynamic and undergo continual improvement.
About Richard Deyo
Dr. Richard Deyo trained as a general internist, and is now the Kaiser Permanente Professor of Evidence-Based Family Medicine and Professor of Medicine at Oregon Health and Science University.
Deyo is a Deputy Editor of Spine, a member of the editorial board of the Back Group of the Cochrane Collaboration, and co-editor of the book Evidence-Based Clinical Practice: Concepts and Approaches. He has authored or co-authored over 300 peer-reviewed scientific articles, mostly concerning back pain. He was a member of the back pain guideline panel for the Agency for Health Care Policy and Research; the National Academy of Science panel on Musculoskeletal Disorders and the Workplace; and co-chair of the NIH Task Force on Research Standards for Chronic Low Back Pain. In 2004, he received the John M. Eisenberg Award for career achievement in research from the Society for General Internal Medicine. He has a long-standing research interest in measuring patient function, involving patients in clinical decisions, and managing low back pain. He has recently been studying inappropriate use of medical technology, and the commercial, political, and media forces that affect it.
References
[1] Deyo, R., Dworkin, S., Amtmann, D., Andersson, G., Borenstein, D., Carragee, E., Carrino, J., Chou, R., Cook, K., DeLitto, A., Goertz, C., Khalsa, P., Loeser, J., Mackey, S., Panagis, J., Rainville, J., Tosteson, T., Turk, D., Von Korff, M., & Weiner, D. (2014). Report of the NIH Task Force on Research Standards for Chronic Low Back Pain J Pain, 15 (6), 569-585 DOI: 10.1016/j.jpain.2014.03.005
[2] Deyo RA, Mirza SK, Turner JA, & Martin BI (2009). Overtreating chronic back pain: time to back off? J Am Boad Fam Med, 22 (1), 62-8 PMID: 19124635