Advancing spine evidence synthesis: North American Spine Society (NASS) Guidelines

Author: Ahmad Ozair ^1,2

1. Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States

2. NASS Evidence-Based Medicine and Clinical Practice Guideline Committees, North American Spine Society, Chicago, IL, United States

Prologue

"Half of what you’ll learn in medical school will be shown to be either dead wrong or out of date within five years of your graduation; the trouble is that nobody can tell you which half."

 – Attributed to David Sackett, MD, FRSC, father of evidence-based medicine.

Introduction

Spinal disorders, ranging from chronic low back pain (LBP) to complex structural abnormalities, affect millions worldwide and pose a substantial socio-economic burden. LBP was estimated to be present in over a quarter of the United States (US) adult population in 2008 and these figures have steadily increased since then.  In the US alone, spending on spine care has exceeded $85 billion annually for almost the last two decades. Yet studies show no corresponding improvement in patient-reported health status among those with spinal problems. Despite this burden, there remains a notable gap in evidence-based guidelines for many aspects of spine care, underscoring the urgent need for creating and synthesizing spine-related evidence.

The complexity of spinal disorders presents unique challenges for researchers and clinicians alike. These conditions often involve a variety of root causes and potential treatments. This makes it difficult to conduct comprehensive studies that provide definitive evidence on specialized interventions for specific diagnoses. This complexity has also led to considerable variability in treatment approaches across different health care providers and settings. Both patients and clinicians face a challenging problem of determining not just what intervention to choose amongst the myriad options available, but also the fundamental question of whether or not to even intervene.  These discussions become more nuanced in an era of increasing telehealth evaluations that lack a hands-on examination, combined with increasing patient confusion due to direct-to-consumer marketing of products that may not be appropriate for a given individual. 

About the North American Spine Society 

The North American Spine Society (NASS) is an interdisciplinary medical organization that fosters the highest-quality, ethical, value- and evidence-based spine care through education, research, and advocacy. NASS was established in 1985 by the merger of the North American Lumbar Spine Association and the American College of Spinal Surgeons, connecting spine care professionals under first president, Leon Wiltse, MD, pioneer of the eponymous, classic paraspinal approach.

In the early 1990s, NASS expanded its focus to include education and guideline development. This shift was driven by the growing recognition of the need for standardized, evidence-based approaches to spine care. The organization's commitment to guideline development was further solidified under the leadership of John P. Kostuik, MD, then chief of spine surgery and chair of the Department of Orthopedics at Johns Hopkins Hospital. Dr. Kostuik broadened NASS' scope to encompass advocacy, guideline creation, and the transition to a more comprehensive society. NASS membership has since evolved to encompass the diversity of spine care, uniting orthopaedic surgery and neurological surgery, as well as physiatry, pain management, research and other disciplines, in its mission to advance the field.

NASS guidelines 

NASS' approach to guideline development is characterized by its rigorous methodology and multidisciplinary collaboration. This process involves systematic literature reviews, critical appraisal of evidence, meta-analysis (if feasible), and a transparent evidence-to-decision recommendation-making process by  spine care experts. Consequently, two committees were established within the NASS Evidence Analysis & Research Council, directed by Steven Hwang, MD. Known as the Clinical Practice Guideline (CPG) Committee and the Evidence-Based Medicine (EBM) Committee, these two entities focus on advancing evidence synthesis.

Led by R. Carter Cassidy, MD,  the CPG Committee comprises experts trained in evidence analysis and uses  an evidence-based guideline development methodology to create recommendations addressing key clinical questions for specific spinal diagnoses. Meanwhile, the EBM Committee, chaired by long-standing EBM pioneer Donna Ohnmeiss, PhD, provides “education and support related to evidence review and analysis, enabling NASS to stay current with the latest developments and approaches in EBM while continuing to promote and advocate for evidence-based spine care.”

The EBM Committee plans, develops, and delivers NASS’ Evidence-Based Medicine Training Program, available at www.spine.org/EBM, a requirement for participating in NASS’ CPG Committee, among others. The course serves as a primer on the fundamentals of EBM for clinicians and researchers across specialties; it provides a framework for the critical appraisal of study methodologies and assignment of evidence levels in relation to specific clinical questions. Open to the public, the training program combines asynchronous didactic modules, learning activities containing spine-specific examples, and a capstone live Q&A webinar.

Over the past two decades, NASS has striven to advance evidence-based spine care through the development of comprehensive clinical practice guidelines, including for diagnosis and treatment for degenerative lumbar spinal stenosis, low back pain,  adult isthmic spondylolisthesis, lumbar disc herniation with radiculopathy, degenerative cervical radiculopathy, and antibiotic prophylaxis in spine surgery, amongst others. Most recently, NASS published guidelines on the diagnosis and treatment of osteoporotic vertebral compression fractures and neoplastic vertebral compression fractures in September 2024. 

One of the most concerning issues has been the disconnect between health care expenditure and patient outcomes. In the United States alone, spending on spine care exceeded $85 billion in 2006, yet there was no corresponding improvement in patient-reported health status among those with spinal problems. This discrepancy underscores the urgent need for evidence-based practices that can deliver better value in spine care. A few papers have directly estimated the cost-benefit and value proposition of following EBM-based recommendations in spine care – a recent paper by Sarikonda and colleagues has demonstrated that spinal fusion cases which were concordant with the NASS recommendations led to “2% greater improvement in Oswestry disability scores (ODI) from baseline for every $1000 spent intraoperatively.” Similarly, patients who met EBM criteria for lumbar fusion had > 3 times improved outcomes from baseline compared with patients not meeting EBM criteria who underwent spinal fusions.

NASS guidelines have become valuable resources not only for spine experts, but other health care professionals, offering evidence-based recommendations to improve patient care globally. 

Large language models and guidelines

The culture and discourse surrounding health literacy and health care information have been rapidly changing in an era of large language models (LLMs) such as ChatGPT, Claude, Bard, etc., which can consume text-based health records, imaging, clinician notes and lab values to output answers related to diagnosis, treatment, and follow-up for patients. However, the quality of these LLM outputs is variable, especially since new versions of models and differently trained models are rapidly iteratively published. Some spine surgeons have previously documented how ChatGPT may suggest wrong interventions in hypothetical cases of acute lumbar disc herniation. Others have reported low inter-rater reliability across models for publicly asked questions related to lumbar spine fusion. This is potentially due to LLM output being based on probabilistic estimates of associations.

While the conversation continues to evolve on the role of LLMs in different facets of spine care, what has been clear is that the quality of text on which the LLM has been trained is likely a critical factor, rather than the quantity of text utilized during the training sessions. Thus, it is essential that there exist publicly available, unbiased sources of information on diagnosis and treatment of spinal disorders, such as NASS guidelines, which these LLMs can synthesize and refer patients to. 

Evidence-related challenges and future directions

Admittedly, “gold-standard,” randomized controlled trials (RCTs) in spine surgery are difficult to conduct and relatively rare. Efforts to synthesize and pool high-quality evidence in spine surgery have been similarly challenging. However, unlike many guideline bodies that only include RCT data, NASS CPG committee members continue to review both RCT and non-RCT evidence in order to arrive at recommendations informed by the best available evidence.

Tobias Mattei, MD, a deputy editor of NASSJ wrote:

“…we are undeniably in the very early stages of our quest for high-quality scientific evidence for most of our routine practices in spine surgery. May we always remember that equally, or perhaps even more important than our final goals in such a laudable scientific endeavor may be the quality of the process through [which] our daily decisions are made while the evidence is not there yet.”

Furthermore, given the increasing global adoption of the GRADE evidence-to-decision approach, NASS recently implemented the GRADE framework in its newest guideline-in-development on sacroiliac joint pain. The GRADE approach allows for a comprehensive and standardized assessment and reporting on the certainty of the body of evidence.

NASS is also working to improve collaboration with other professional societies, seeking their endorsement for NASS-developed guidelines. NASS is also directly collaborating on development with multiple professional societies, such as for the guidelines on “Use of corticosteroids for adult chronic pain interventions: Sympathetic and peripheral nerve blocks, trigger point injections,” which were developed together with the American Academy of Pain Medicine, the American Society of Regional Anesthesia and Pain Medicine, the American Society of Interventional Pain Physicians, and the International Pain and Spine Intervention Society.

In short, NASS guidelines often reveal areas where evidence is lacking or inconclusive, highlighting the ongoing need for high-quality research in spine care, even in the presence of artificial intelligence. By addressing these evidence gaps, the spine care community can work toward more standardized, effective and value-based care for patients with spinal disorders. This approach not only has the potential to improve patient outcomes but also to optimize resource utilization in an increasingly cost-conscious health care environment.

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Links to additional resources

View NASS’ published and in-progress Clinical Practice Guidelines here: https://www.spine.org/Research/Clinical-Guidelines

Learn more about NASS’ Online Evidence-Based Medicine Training at www.spine.org/EBM 

Interested in joining NASS? Visit https://www.spine.org/Membership/Join

Already a NASS member, but unsure how to get involved? Learn more at https://www.spine.org/getinvolved

To link to this article - DOI: https://doi.org/10.70253/UKWL6380

Acknowledgements

The Evidence-Based Medicine (EBM) Committee of the North American Spine Society (NASS) discussed signing on as an Ambassador to World Evidence-Based Healthcare Day on behalf of NASS at a summer 2024 meeting. Dr. Ozair, an engaged member of the EBM and Clinical Practice Guideline (CPG) Committees, proposed focusing on NASS’ CPG and EBM efforts. The blog was revised by Donna Ohnmeiss, PhD, Chair of EBM Committee and NASS staff, prior to review by R. Carter Cassidy, MD, Chair of CPG Committee and Steven Hwang, MD, Director of Evidence Analysis & Research Council. Finally, approval was acquired from NASS’ 2023-2024 and 2024-2025 Executive Committees (Zoher Ghogawala, MD, FACS, Past President; Scott Kreiner, MD, President; William Mitchell, MD, 1st Vice President; John Finkenberg, MD, Past President; David O’Brien, MD, Outgoing Secretary; Mitchell Reiter, MD, PC, Outgoing Treasurer; Christopher Kauffman, MD, 2nd Vice President; D.J. Kennedy, MD, Secretary; Patrick Hsieh, MD, MBA, MS, Treasurer).

Conflict of interest

Ahmad Ozair is an unpaid member of the NASS Evidence-Based Medicine (EBM) and Clinical Practice Guideline (CPG) Committees. 

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