Research Review By Dr. Demetry Assimakopoulos©


Download MP3

Date Posted:

January 2019

Study Title:

A Scoping Review of Biopsychosocial Risk Factors and Co-morbidities for Common Spinal Disorders


Green BN, Johnson DC, Haldeman S et al.

Author's Affiliations:

Qualcomm Health Center, Stanford Health Care, San Diego, California, USA; Publications Department, National University of Health Sciences, Lombard, Illinois; Department of Neurology, University of California, Irvine, California; Department of Epidemiology, School of Public Health, University of California, Los Angeles, California; World Spine Care, Santa Ana, California; Emergency Medicine, Carlsbad, California; Rehabilitation Care Line, Physical Medicine and Rehabilitation, Cincinnati Veterans Affairs Medical Center, Cincinnati, Ohio; College of Rehabilitative Sciences, Doctor of Physical Therapy Program, University of St. Augustine for Health Sciences, San Marcos, California; National School of Occupational Medicine, Carlos III Institute of Health, Complutense University of Madrid, Madrid, Spain; Department of Orthopaedics, Ganga Hospital, Coimbatore, Tamil Nadu, India; Section of Physical Medicine and Rehabilitation and Department of Orthopaedic Surgery, Stanford University, Redwood City, California; Office of Public Health Studies, University of Hawaii, Mānoa, Honolulu, Hawaii; UOIT-CMCC Centre for Disability Prevention and Rehabilitation, University of Ontario Institute of Technology, Toronto, Canada; Department of Undergraduate Education, Canadian Memorial Chiropractic College, Toronto, Canada; Department of Orthopedic Surgery, New York University, New York, New York; Department of Environmental Medicine, New York University, New York.

Publication Information:

PLoS ONE 2018; 13(6): e0197987.

Background Information:

In general, spinal disorders are a formidable healthcare challenge, causing substantial morbidity, disability and suffering worldwide. The prevalence of spinal disorders has increased sharply, and they are now the leading cause of disability around the globe. In order to address these burdens at all stakeholder levels, it is necessary to identify the multitude of biopsychosocial factors that increase the risk of suffering. This study offers a scoping review of the biopsychosocial risk factors, prognostic factors and comorbidities associated with the most commonly presenting spinal disorders globally. It is important to note that this project was undertaken by World Spine Care (WSC) and The Global Spine Care Initiative (GSCI), whose missions are to enable access to high quality spine care around the world, and to create an evidence-based pathway and model of care to guide clinicians, policy makers and public health programs.


A total of 145 studies were included for review. Systematic reviews were found for each term, with the exception of tuberculosis, for which the authors reviewed epidemiological studies.

This paper endeavored to address spinal disorders affecting any region that a wide range of clinicians diagnose and/or treat in clinical practice. The following 3 groups were developed for the purpose of focusing the search strategy:

Group 1 - Spinal Pain of Unknown Origin:

This group of spinal disorders represents back pain for which no other cause can be found or attributed. History and examination findings fail to yield a specific clinical diagnosis. Diagnostic imaging, laboratory and neurodiagnostc findings are unremarkable. Examples include neck pain, thoracic pain, low back pain, and coccygodynia of unknown origin (18). A total of 67 studies were reviewed for this group:
  • Risk Factors: Psychosocial work variables of high job demands [pooled OR = 1.17] and highly monotonous work [pooled OR = 1.30] were risk factors for future neck pain. Poorer mental health [pooled OR = 1.4] and being an older adolescent [OR = 6.3] were identified as risk factors for thoracic back pain in adolescence in prospective studies. For low back pain, risk factors included current [pooled OR = 1.31] and any history of smoking [OR = 1.32], negative expectations about recovery in sub-acute populations [OR = 2.17], high job demands [OR = 1.42], low social support [OR= 1.36], low supervisor support [OR = 1.33], low job satisfaction [OR 1.31] and depressive symptoms [OR = 1.59]. Low job control, high job strain, low job security and highly monotonous work were not considered risk factors.
  • Associations: With regards to neck pain numerous, but conflicting associations were referenced, including female sex, psychological status, low work support, prior history of neck, low back or other MSK-pain, prolonged sitting/sedentarism, poor health, no or low levels of physical activity and smoking. Backpack use, postural changes, female sex (in children), later stage of puberty (in adolescents), and difficulty performing ADLs were associated with thoracic spine pain. Risk associations for low back pain include exposure to whole body vibration [OR 1.39-2.3], obesity (in multiple age groups), work-related manual materials [OR 1.51-4.1], low job satisfaction, frequent bending and twisting [OR = 1.6 – 7.5] and age > 45 in workers.
  • Comorbidities: Overall ill-health, and MSK or generalized pains were mentioned as comorbidities for neck pain. Comorbidities mentioned for thoracic pain include suffering from other MSK symptoms, and mental health concerns in adolescents. Comorbidities of psychiatric conditions, diabetes, osteoarthritis, osteoporosis, chronic fatigue syndrome, fibromyalgia, cardiovascular conditions, sciatica, pain at other sites and other MSK injuries were associated with low back pain.
Group 2 – Spinal Syndromes:

This group is characterized by historical and examination findings that lead to a clinical diagnosis. Diagnostic imaging, laboratory and neurodiagnostic procedures are typically non-confirmatory. Examples include radicular pain, brachial plexopathy, joint pain syndromes, myofascial pain, soft tissue injuries and torticollis. Spinal syndromes in this group often improve when the primary pain generator is targeted and treated. A total of 11 papers were included in this group:
  • Risk Factors: Obesity, overweight, manual labour and current smoking were risk factors for sciatica [OR not reported in this systematic review]. High initial pain intensity [OR = 5.6] and catastrophizing [OR = 3.77] were noted as poor prognostic factors for recovery from WADs. However, the greatest prognostic factor for poor recovery from whiplash was a Neck Disability Index score > 15 [OR 42.2!].
  • Associations: The onset of spinal-related pain was firmly associated with whole body vibration from occupational vehicles [OR 2.0], overweight/obesity, smoking, high levels of physical activity (in sciatica), and altered motor control and kinematics of the pelvis (pelvic pain during pregnancy).
  • Comorbidities: Several were identified for WADs, including: psychological disorders, back pain, headache, widespread chronic pain, degenerative changes, radicular symptoms, cranial nerve/brainstem disturbance, dizziness, dysphagia, fatigue and high obesity.
Group 3 – Spinal Pathology:

This group is characterized by historical and examination findings leading to a clinical diagnosis that can be confirmed by diagnostic imaging, laboratory and/or neurodiagnostic examination. Examples include tumours, osteoarthritis, fracture, dislocation, cord disorders, myelopathy, infection, osteopenia, scoliosis, spinal bifida, spondylolisthesis and vertebral osteochondrosis (15-17). Psychologically mediated spinal pain disorders were not included. This group was particularly large, and as such, the data were separated into several subgroups including: osteoarthritis/degenerative spinal factors (10 studies); trauma (14 studies); tuberculosis (4 case-control studies); osteoporosis/metabolic spinal disorders (23 studies); and congenital/developmental factors (11 studies). The reported risk factors for osteoporosis are in addition to the well-known risk factors of female sex, white race and older age.

Risk factors:
With regards to osteoarthritis/degenerative spinal disorders smoking is considered a risk factor for lumbar disc herniation [RR = 1.27]. Interestingly, an active worker’s compensation claim was a negative prognostic factor for recovery after cervical radiculopathy from disc herniation. Scoliosis was also associated with degenerative spinal disease.

Reported risk factors for traumatic spinal injury were male sex, and ages between the range of 20-29 yrs and > 70 yrs. Interestingly, male sex and age > 70 were risk factors for non-traumatic spinal cord injury. Those with spinal cord injury have twice the mortality rate of the general population, with increasing age [HR = 1.06] and male sex [HR = 1.29] being the most prominent prognostic factors.

Several risk factors for spinal tuberculosis were reported but were inconsistent across studies depending on geographic region and population. The primary risk factors for TB were age > 35, history of imprisonment, male sex, previous history of TB infection, genetic polymorphism of monocyte chemotactic protein-1 and delay in diagnosis. Clinical findings indicative of worsening spinal TB include severe vertebral collapse, age < 7 years at time of diagnosis, involvement of the TL area and loss of > 2 vertebral bodies. Signs of vertebral instability were indicative of worse outcomes in TB populations.

Risk factors for osteoporosis/metabolic spinal disorders include pre-existing medical conditions (type-1 diabetes, increased BMI in type-2 diabetes, untreated hyperprolactinemia), medication usage (vitamin K antagonists for anticoagulant use, SSRI in older patients, proton pump inhibitors) and health behaviours (current smoking). Interestingly, use of dietary calcium, calcium supplements and vitamin D supplementation failed to show a decrease in vertebral fractures or increase in bone mineral density. Low dose flouride supplementation (< 30 mg fluoride equivalents), menaquinone-4, isoflavone supplementation and hormone replacement therapy showed a reduction in vertebral fractures.

Several risk factors for congenital/developmental spinal disorders were identified, including anti-epileptic medication and carbamazepine use [2x risk for spina bifida], valproic acid use [OR for spina bifida/neural tube defects = 7.6 – 12.7], and prenatal exposure to influenza and chlorine. Interestingly, maternal obesity was associated with twice the risk for spina bifida and neural tube defects. Folic acid supplementation was deemed protective against neural tube defects [RR = 0.31 – 0.43].

Males had a higher risk of cervical radicular symptoms, if cervical disc protrusion was identified. Overweight or obese dizygotic same sex twins, the presence of vitamin D polymorphisms, whole body vibration, smoking and general overweight and obesity showed increased risk for lumbar disc degeneration and spinal degenerative changes. Lumbar spondylolisthesis is significantly more prevalent in occupational populations [OR = 2.21]. One study showed increased association between disc infection and DDD (this association remains controversial).

MVA, falls, violence and sports injuries are known to be the most common causes of traumatic spinal disorders; while tumours, degenerative changes and vascular problems are associated as the most common causes of non-traumatic spinal lesions. Interestingly, mortality is associated more so with spinal trauma, compared to non-traumatic spinal cord injury. The degree of mortality in this regard was elevated by a number of factors, including increased age at the time of injury, pre-existing co-morbidities and higher injury score. Prognostic indicators of worse recovery include greater age at lesion onset, higher neurological levels and completeness of damage. Interestingly, the prevalence of pain increased as time passed following a spinal cord injury.

With regards to metabolic spinal disorders, small vertebral body dimensions were positively associated with osteoporotic vertebral fracture in one study (1). The presence of fat mass may have an influence on bone metabolism and density through the production of adipokines and adiponectin is negatively associated with bone density (independent of sex and the quantity of fat mass). A meta-analysis showed that 9 out of 150 genes are association with BMD regulation, and that 4 of these genes affect risk for vertebral fracture (2). Interestingly, education may have a protective effect on BMD of the lumbar spine.

In the context of congenital/developmental spinal disorders high Cobb angle (OR = 7.6), thoracic curve (OR = 2.3), osteopenia (OR = 2.6), < 13 yoa (OR = 2.7), and pre-menarche diagnosis (OR = 4.0) are associated with progressive severe scoliotic deformity.

There were several co-morbid factors with spinal trauma, including depression/depressive symptoms, anxiety, PTSD, high levels of pain, chronic pain, cardiovascular disease, ankylosing spondylitis, osteoarthritis, renal pathology, neoplasia, cerebral pathology and peripheral neuropathy. Chronic renal failure, diabetes, and HIV are comorbid conditions with spinal tuberculosis. No comorbidities were identified for OA/degenerative spinal conditions, and congenital/developmental spinal disorders.

Clinical Application & Conclusions:

This paper certainly represents ‘big picture’ stuff, serving as a comprehensive, scoping review of biopsychosocial risk factors, prognostic factors, associations and comorbidities for a range of spinal disorders, including degenerative spinal conditions, spinal trauma, metabolic disorders, tuberculosis and congenital/developmental spinal disorders.

It is obvious from this review that spinal disorders are multi-factorial and multi-morbid. This variability is likely because sufferers themselves, including their social structures and communities, are variable and complex. This strengthens the argument that epidemiological analyses should include ecosocial processes and community and psychosocial frameworks, in addition to just comorbidities and demographic variables.

Of note is the notion of sociodemographic variables, such as income level, which may have relevance to certain chronic diseases, including MSK disorders. It is a well-known fact that low-income countries have higher risk for a range of MSK disorders. It may be necessary for higher-income countries to assist low- and middle-income countries with gaining better control of spinal disorders.

While this review reveals both comorbidities and prognostic factors for common spinal disorders, several associated risk factors for spinal disease are modifiable and may be a fertile ground for initiating community-based public health programs or research.

Study Methods:

The authors performed a scoping review using pre-identified methods, in order to discover gaps in the research literature. Unlike systematic reviews, scoping reviews do not focus on highly specific questions (12), do not involve formal qualitative assessment of each reviewed paper (13) and do not provide lengthy critical appraisals of the reviewed literature (10). The authors utilized the following step-wise investigative process for their review:
  1. Identification of the research question;
  2. identification of relevant studies;
  3. use of an iterative team approach to study selection and data extraction;
  4. charting the data using quantitative and qualitative methods; and
  5. summarizing the results to include implications for policy, practice and research.
The authors did not attempt to rate the quality of each article or any risk of bias, as these topics do not fit within the paradigm of a scoping review.

The authors operationally defined “spinal disorders” as: ”a wide and heterogeneous variety of diseases affecting the vertebrae, intervertebral discs, facet joints, tendons, ligaments, muscles, spinal cord and nerve roots of the spine.” This paper addressed spinal disorders affecting any region that a wide range of clinicians diagnose and/or treat in clinical practice. They defined 3 groups (or types) of spinal pain for the purpose of focusing the search strategy – these are defined in the summary section above.

A complete list of spinal syndromes that were included and not included is featured in the full text article (which is open access).

English-language, peer-reviewed papers eligible for consideration included systematic reviews (with or without meta-analysis) of cohort, case-control, cross-sectional studies, or RCTs. If no systematic review was available for a spinal disorder, the search strategy was expanded to include case-control or cohort studies published within 10 years that included risk or prognostic factors with measures of association. The authors included adult and child populations, and were inclusive of any demographic, so long as the study presented risk/prognostic factors related to morbidity and/or mortality. Letters, editorials, commentaries, unpublished manuscripts, dissertations, government reports, books/chapters, conference proceedings, meeting abstracts, lectures/addresses, consensus development statements, case reports, case series, qualitative studies, non-systematic reviews, post-surgical topics, guideline statements, protocols for systematic reviews/meta-analyses, animal studies and pharmacological studies were excluded. Risk factors were defined as any attribute, characteristic or exposure of an individual that increased the likelihood of developing a spinal disorder, or morbidity/mortality as a result of that disorder. Prognostic factors were defined as factors that affect or determine the course of a disorder once the person already has the disorder.

Study Strengths / Weaknesses:

The strengths of this study were inclusion of a multi-disciplinary international team of authors, who focused on practical patient and clinical information to inform a care pathway and model of care for spinal disorders. It is also the first study of its kind to provide a relatively complete collection of the risk factors, associations and comorbidities as they relate to spinal disorders. The authors also utilized a lengthy list of search terms to represent the entire breadth of spinal disorders completely.

Weaknesses of this study include the relatively tight eligibility criteria, which may have excluded certain spinal disorders (such as “discogenic pain”), inconsistency among included papers, and limited conclusions based on inconsistent data between studies. Unfortunately, due to the nature of the research question and the broad methodological limitations that come alongside a scoping review, the authors were unable to completely pool the data and perform a meta-analysis. Additionally, most of the studies from the groups “Spinal Pain of Unknown Origin” and “Spinal Syndromes” were from low- or middle-income populations where the risk factors and spinal conditions themselves may be quite different from higher-income populations. The scope of this review was very broad and not amenable to an in-depth investigation into socioeconomic variables across geographic areas. The authors also did not seek to determine whether comorbidities were discovered by chance, selection bias or by association. Finally, it should be noted again that by its very nature, scoping reviews do not focus on highly specific questions, do not formally qualitatively evaluate each included paper, and do not provide lengthy critical appraisals of the reviewed literature.

Additional References:

  1. Ruyssen-Witrand A, Gossec L, Kolta S et al. Vertebral dimensions as risk factor of vertebral fracture in osteoporotic patients: a systematic literature review. Osteoporos Int 2007; 18(9): 1271–8.
  2. Richards JB, Kavvoura FK, Rivadeneira F, et al. Collaborative meta-analysis: associations of 150 candidate genes with osteoporosis and osteoporotic fracture. Ann Intern Med 2009; 151(8): 528–37.
  3. Tricco AC, Lillie E, Zarin W, O’Brien K, Colquhoun H, Kastner M, et al. A scoping review on the conduct and reporting of scoping reviews. BMC Med Res Methodol 2016; 16: 15.
  4. Peters MD, Godfrey CM, Khalil H, McInerney P, Parker D, Soares CB. Guidance for conducting systematic scoping reviews. Int J Evid Based Healthcare 2015; 13(3): 141–6.
  5. Grant MJ, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Info Libr J 2009; 26(2): 91–108.
  6. International Association for the Study of Pain Taxonomy Working Group. Classification of Chronic Pain. 2nd (revised) ed. Washington, DC: International Association for the Study of Pain. Available from: 1673&navItemNumber=677; 2011.
  7. Elfering A, Mannion AF. Epidemiology and risk factors of spinal disorders. In: Boos N, Aebi M, editors. Spinal Disorders: Fundamentals of Diagnosis and Treatment. Berlin: Springer-Verlag; 2008. p. 153– 73.
  8. Deyo RA, Weinstein JN. Low back pain. N Engl J Med 2001; 344(5): 363–70.
  9. Haldeman S, Kopansky-Giles D, Hurwitz EL, Hoy D, Mark Erwin W, Dagenais S, et al. Advancements in the management of spine disorders. Best Pract Res Clin Rheumatol 2012; 26(2): 263–80.