Research Review By Dr. Jeff Muir©

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Date Posted:

September 2015

Study Title:

Clinical examination findings as prognostic factors in low back pain: a systematic review of the literature

Authors:

Hartvigsen L, Kongsted A, Hestbaek L

Author's Affiliations:

Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark.

Publication Information:

Chiropractic & Manual Therapies 2015; 23: 13. DOI 10.1186/s12998-015-0054-y

Background Information:

Low back pain (LBP) is now the leading cause of disability worldwide (1), with some estimates suggesting that up to 1/3 of adults have low back pain at any given time (2)! Low back pain can be viewed as both an episodic and recurrent condition, with acute and chronic back pain both leading to significant health care expenditures and patient morbidity (1, 2).

The clinical examination is central to the assessment and diagnosis of low back pain; however, evidence suggests that the validity, reliability and diagnostic accuracy of tests commonly utilized are low (3-7) and the predictive ability of these tests regarding prognosis is questionable (8-10). No studies have reviewed the prognostic value of the various clinical tests utilized during the patient assessment and examination. The purpose of this study, as stated by the authors, was “to examine the extent and quality of the evidence on clinical examination findings as prognostic factors by systematically and critically reviewing the literature dealing with the association between low-tech clinical tests used in adult patients with acute, recurrent, or chronic LBP and at least one of the outcomes of pain, disability, return to work, use of health care services or medication, or global improvement”.

Pertinent Results:

Study Selection:
From an initial pool of 5332 records, 49 publications based on 47 studies were included in the final analysis.

Study Characteristics:
All studies were prospective cohort studies: 13 were secondary analyses of RCTs. Short-term (n = 16) or long-term (n = 24) follow-up (or both – n = 9) were included in the eligible studies.

Physical Examination Prognostic Indicators:

Symptom response classification (centralization/peripheralization): There is consistent evidence for centralization being a prognostic factor for less short-term pain and conflicting evidence for an association with disability (although, the main study creating this conflict utilized only one centralization movement, which is not normally how this is utilized in practice). Using a dichotomous outcome, centralizers generally showed no greater rate of treatment success compared to the total cohort. However, success rates among patients demonstrating peripheralization were lower than the total cohort (28% vs. 45%) (11).

Palpation: No evidence was found indicating an association between palpation for pain, tone or symmetry and short- or long-term outcomes.

Range of motion: No evidence was found supporting an association between spinal ROM and short- or long-term outcome success. For fingertip-to-floor distance (FFD), conflicting evidence suggests this test may be an indicator for short-term outcomes. Limited evidence supports its role as a predictor for long-term outcomes. For Schober’s test, there is conflicting evidence indicating this test may be indicative of long-term outcome success. Sacroiliac joint motion tests were associated with limited evidence and no association with short-term outcomes.

Pain on spinal movement: Conflicting evidence exists for an association with short-term outcomes; no evidence indicates an association with long-term outcome success.

Pain provocation tests: No evidence indicates short-term outcome success, save for Gaenslen’s test, for which there is conflicting evidence. No evidence supports an association with long-term outcomes. For the prone instability test, evidence shows no association with short-term outcomes (no long-term outcome evidence was available). The percussion test has no evidence supporting either short- or long-term outcome success.

Strength and endurance: There is consistently no evidence of an association between muscle endurance or strength and short-term outcome. No evidence was found to support an association between disability or return-to-work and long-term outcome success.

Neurological tests: No evidence exists supporting neurological signs as indicators for either short- or long-term outcome success. The evidence for SLR, crossed SLR, and femoral stretch test as prognostic factors for short-term outcome is conflicting. For Naffziger sign (exacerbation of pain and paresthesias of the hand and fingers when the examiner exerts pressure on the anterior scalene muscles), the evidence shows no association with short-term outcomes.

Non-organic signs: There is consistent evidence of non-organic signs being indicative of long-term poor outcomes regarding return-to-work. Patients with ≥ 3 non-organic signs returned to work an average of 44 days later than those with fewer signs.

Functional tests and leg-length discrepancy (LLD): No evidence exists supporting an association between either functional tests or LLD for short- or long-term outcome success.

Clinical Application & Conclusions:

This review found that the majority of evidence in support of clinical examination tests and (more specifically) their ability to predict short- and/or long-term outcome success was of generally low quality. Centralization was the only factor with consistent evidence of an association with short-term disability. Non-organic signs were the only factors closely associated with long-term outcome success (specific to return-to-work).

It is important to remember that while the value of clinical testing in predicting short- and/or long-term success may be minimal, a poor association with prognosis does not discredit a given test from being helpful diagnostically, or otherwise informative for clinical management. Many clinical tests still have potential as informative treatment effect modifiers as part of comprehensive predictive models. As such, they should be put into the context of the whole patient history and response to treatment.

Study Methods:

This study was performed in adherence with the PRISMA guidelines (12).

Search Strategy:
The following databases were searched for studies published from inception to June 2012: PubMed, MEDLINE, Embase, MANTIS.

Study Inclusion Criteria:
  1. Investigated low-tech clinical tests,
  2. reported the statistical association between clinical examination findings at baseline and at least one of the outcomes of pain, disability, return to work, use of health care services or medication, and global improvement,
  3. had a sample size of ≥ 50 with a follow-up of ≥ 7 days, and
  4. were published in English, Danish, Swedish or Norwegian.
Prospective clinical studies concerning adult patients with LBP with or without leg pain and/or signs of nerve root involvement or spinal stenosis, receiving no or non-surgical treatment, were also included.

Studies were excluded if:
  • They did not involve clinical populations,
  • LBP could not be isolated from other conditions,
  • participants were pregnant,
  • participants had specific diseases such as inflammatory disease, tumor, fracture, or cauda equina,
  • the clinical test involved equipment that could not be expected to be generally available in primary care practice, or
  • the choice of treatment was based on the results of the clinical tests.
Quality Assessment:
The methodological quality of the included studies was assessed independently by two reviewers using five domains of potential bias based on the work by Hayden et al. (13, 14).

Data Synthesis & Analysis:
Associations were considered statistically significant if the reported p-value was < 0.05 or if the 95% confidence interval for odds/risk ratios did not include 1.0.

Strength of Evidence:
Strength of evidence was evaluated using four levels of evidence:
  1. Consistent evidence: consistent findings in two or more studies, or at least 75% of the studies reporting similar conclusions (one of the studies should be of high quality).
  2. Limited evidence: findings in one study of high quality or two or more studies of low quality.
  3. Conflicting evidence: < 75% of available studies reporting similar findings, or contradictory findings present within one study.
  4. No evidence: the prognostic factor in question was investigated in none, or only one study of low or moderate quality (15).

Study Strengths / Weaknesses:

Strengths:
  • The comprehensive and detailed search strategy and presentation of findings is the biggest strength of this study.
Limitations:
  • The authors were often unable to extract all the relevant information from the reports.
  • The overall methodological quality of the eligible studies limits the veracity with which conclusions can be drawn from the data.
  • The heterogeneity among patient populations and treatment methods also limits the conclusions.
  • There are difficulties associated with identifying eligible studies, due to poor indexing of prognostic publications.

Additional References:

  1. Vos T, Flaxman AD, Naghavi M et al. Years lived with disability (YLDs) for 1160 sequelae of 289 diseases and injuries 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012; 380(9859): 2163–96.
  2. Walker BF. The prevalence of low back pain: a systematic review of the literature from 1966 to 1998. J Spinal Disord 2000; 13(3): 205–17.
  3. Al Nezari NH, Schneiders AG, Hendrick PA. Neurological examination of the peripheral nervous system to diagnose lumbar spinal disc herniation with suspected radiculopathy: a systematic review and meta-analysis. Spine J 2013; 13(6): 657–74.
  4. Hestbaek L, Leboeuf-Yde C. Are chiropractic tests for the lumbo-pelvic spine reliable and valid? A systematic critical literature review. J Manipulative Physiol Ther 2000; 23(4): 258–75.
  5. Deville WL, van der Windt DA, Dzaferagic A et al. The test of Lasegue: systematic review of the accuracy in diagnosing herniated discs. Spine 2000; 25(9): 1140–7.
  6. Stochkendahl MJ, Christensen HW, Hartvigsen J et al. Manual examination of the spine: a systematic critical literature review of reproducibility. J Manipulative Physiol Ther 2006; 29(6): 475–85. 485 e471-410.
  7. Triano JJ, Budgell B, Bagnulo A et al. Review of methods used by chiropractors to determine the site for applying manipulation. Chiro Man Ther 2013; 21(1): 36.
  8. Chorti AG, Chortis AG, Strimpakos N et al. The prognostic value of symptom responses in the conservative management of spinal pain: a systematic review. Spine 2009; 34(24): 2686–99.
  9. Kent PM, Keating JL. Can we predict poor recovery from recent-onset nonspecific low back pain? A systematic review. Man Ther 2008; 13(1): 12–28.
  10. Borge JA, Leboeuf-Yde C, Lothe J. Prognostic values of physical examination findings in patients with chronic low back pain treated conservatively: a systematic literature review. J Manipulative Physiol Ther 2001; 24(4): 292–5.
  11. Flynn T, Fritz J, Whitman J et al. A clinical prediction rule for classifying patients with low back pain who demonstrate short-term improvement with spinal manipulation. Spine 2002; 27(24): 2835–43.
  12. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 2010; 8(5): 336–41.
  13. Hayden JA, Cote P, Bombardier C. Evaluation of the quality of prognosis studies in systematic reviews. Ann Intern Med 2006; 144(6): 427–37.
  14. Hayden JA, van der Windt DA, Cartwright JL, Cote P, Bombardier C. Assessing bias in studies of prognostic factors. Ann Intern Med 2013; 158(4): 280–6.
  15. Verkerk K, Luijsterburg PA, Miedema HS et al. Prognostic factors for recovery in chronic nonspecific low back pain: a systematic review. Phys Ther 2012; 92(9): 1093–108.