February 4, 2014

Variables Predicting Spinal Surgery After Injury

First contact with chiropractors associated with lower rates of surgery
As pressure to rein in escalating healthcare costs mounts, so does scrutiny of costly, aggressive treatment paradigms.


Keeney BJ, Fulton-Kehoe D, Turner JA, Wickizer TM, Chan KCG, Franklin GM. Early predictors of lumbar spine surgery after occupational back injury. Spine. 2012 Dec 12. [Epub ahead of print.]


Prospective population-based cohort study


1,885 male and female Washington state employees filing worker's compensation total temporary disability claims between June 2002 and April 2004 for lumbar spine injuries

Parameters Assessed

Using Disability Risk Identification Study Cohort data, the authors examined early predictors of lumbar spine surgery using bivariate and multivariate analysis. Variables included sociodemographics, employment characteristics, pain and function parameters, clinical status, healthcare providers utilized, health behaviors, and psychological parameters.

Primary Outcome Measures

Number of lumbar spine surgeries within a 3-year period of filing the original new injury claim with the Washington State Worker's Compensation department.

Key Findings

Six variables were found to independently contribute to the likelihood of lumbar spine surgery (P<0.05). The significant variables included a higher baseline score on the Roland-Morris Disability Questionnaire (RMDQ), greater injury severity, surgical consultation as the first provider seen, age between 35 and 44, non-Hispanic Caucasian ethnicity, and male gender. Factors associated with significantly reduced odds of surgery included Hispanic ethnicity, age less than 35, female gender, and seeing a chiropractor as the first provider after injury.

Clinical Implications

Work-related lumbar spine injury is common and costly and represents a significant healthcare expense for employers and insurers of the working population in this country.1,2 Costs related to spinal injury care have risen sharply over the last 2 decades, and questions regarding the clinical benefit and cost effectiveness of surgical interventions have been raised.3,4 As pressure to rein in escalating healthcare costs mounts, so does scrutiny of costly, aggressive treatment paradigms. Likewise, objective consideration of more conservative, less costly interventions should occupy a place in the healthcare expenditure discussion.
The current study attempts to delineate factors that may help identify patients who are more likely to undergo lumbar spine surgery following a work-related injury. Not surprisingly, patients who suffer a more severe original injury and those who score higher on a standardized disability rating instrument are more likely to undergo surgery. Patients with the highest disability scores as measured by the RMDQ had a sixfold higher likelihood of surgery than those with the lowest RMDQ scores. Likewise, patients with radiculopathy, sensory, motor, or reflex abnormalities had an odds ratio of 5.63 for undergoing surgery.
As pressure to rein in escalating healthcare costs mounts, so does scrutiny of costly, aggressive treatment paradigms.
Interestingly, but perhaps not surprising for practitioners familiar with chiropractic and other conservative physical medicine approaches, patients who first saw a chiropractor had a dramatically lower incidence of eventual surgery. In this cohort, approximately 1.5% of patients first evaluated by a chiropractor had spinal surgery. In contrast, 43% of injured workers who first saw a surgeon underwent surgery within a 3-year period. As the authors note, “It is possible that these finding indicate that 'who you see is what you get.'” While the research on the efficacy of chiropractic spinal manipulative therapy is inconclusive and contradictory, its persistent use by the general public attests to some level of efficacy for the treatment of low back pain.5,6 The above reviewed article is significant in that it illustrates in very clear statistical language the phenomenon of "if all one has is a hammer, everything looks like a nail" as it relates to therapeutic decision-making in a healthcare setting. While it is possible that practitioner selection by less severely injured patients may have contributed to the lower surgery rate by chiropractic patients, the statistics show that the high surgery rate among patients first evaluated by surgeons is not due to chance (P<0.0001).
The specific implications of this study are clear as stated above: Patients who are severely injured and have high disability rating scores are likely to have surgery due to the nature and severity of their injuries. Those consulting surgeons are far more likely to have surgery than those consulting chiropractors for their lumbar spine injuries. The general implications are greater. In these times of healthcare expenditure scrutiny, more conservative and less invasive interventions—even for significant injuries and illnesses—deserve rigorous evaluation of their therapeutic efficacy and cost-effectiveness. 

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  1. Courtney TK, Webster JS. Disabling occupational morbidity in the United States. J Occup Environ Med. 1999(41):60-69.
  2. Guo HR, Tanaka S, Halperin WE, et al. Back pain prevalence in the US industry and estimates of lost workdays. Am J Public Health. 1999(89):1029-1035.
  3. Deyo RA, Mirza SK, Turner JA, et al. Over treating chronic back pain: time to back off? J Am Board Fam Med. 2009(22):62-68.
  4. Chou R, Baisday J, Carragee EJ, et al. Surgery for low back pain: a review of the evidence for an American Pain Society Clinical Practice Guideline. Spine. 2009(34): 1094-1099.
  5. Rubinstein SM, Terwee CB, Assendelft WJ, de Boer MR, van Tulder MW. Spinal manipulative therapy for acute low-back pain. Cochrane Database Syst Rev. 2012 Sep 12:9 CD 008880.
  6. Bronfort G, Haas M, Evans RL, Bouter LM. Efficacy of spinal manipulation and mobilization for low back pain and neck pain; a systematic review and best evidence synthesis. Spine J. 2004;4(3):335-356.