Best Evidence Topics


Jack Sava, MD, Michael D. Williams, MD, Susan Kennedy, RN, and Dennis Wang, MD
Thoracolumbar Fracture in Blunt Trauma: Is Clinical Exam Enough for Awake Patients?
J Trauma
2006 Jul; 61(1):168-71
  • Submitted by:Nicholas Kuhl - Physician
  • Institution:Grand Rapids Medical Education and Research Center
  • Date submitted:23rd August 2007
Before CA, i rated this paper: 6/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes. The study was designed to prospectively test the reliability of clinical examination in detecting thoracolumbar fracture (TLFx) in patients who have a slight alteration in mental status.
2 Design
2.1 Is the study design suitable for the objectives
  Yes. The authors used a prospective cohort study of all trauma patients undergoing imaging for possible TLFx.
2.2 Who / what was studied?
  Patients at an urban level 1 trauma center who underwent imaging to rule out TLFx according to hospital protocol despite GCS >13 and clinician judgment of reliability.
2.3 Was this the right sample to answer the objectives?
  Yes. All trauma patients with possible TLFx were included and only those not requiring confirmatory imaging due to lack of risk factors for TLFx were excluded.
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  Unknown. Authors did not provide goal sample size estimates and no study power calculations were presented.
2.5 Were all subjects accounted for?
  Yes, as authors state "All patients undergoing thoracolumbar radiography were included in the study." However, no specific enrolment statistics are reported and an evaluation form completion rate of 100% seems unlikely.
2.6 Were all appropriate outcomes considered?
  No. Clinical identification of TLFx was the primary outcome, presented with calculated sensitivity and specificity data. Observational data regarding subsequent treatments were reported. A separate calculation of diagnostic statistics with treatable TLFx as the outcome would have been informative.
2.7 Has ethical approval been obtained if appropriate?
  Unknown. No report of IRB approval. Collection of informed consent was not discussed, likely due to practical impossibility in the selected patient population.
2.8 Was an independent blinded gold standard test applied to all subjects?
  Yes. At the time of initial evaluation, all patients in the study were evaluated by senior surgical residents or attendings using a worksheet. Following this, the gold standard of thoracolumbar X-ray evaluation was applied to all patients.
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes. Clinical evaluation worksheet was clearly described. Thoracolumbar X-ray evaluation was not described in detail, but is fairly uniform.
3.2 Are the measurements valid?
  Yes. Clinical worksheet included all signs and symptoms relevant to TLFx evaluation.
3.3 Are the measurements reliable?
  Unknown. No kappa or other inter- and intra-rater statistics were reported. Each patient's evaluation was recorded by worksheet only once.
3.4 Are the measurements reproducible?
  Yes, provided details of the worksheet and TLFx imaging used are made available.
4 Presentation of results
4.1 Are the basic data adequately described?
  Yes, although much of the study's results are presented solely in the discussion section.
4.2 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
4.3 Are the results internally consistent, i.e. do the numbers add up properly?
5 Analysis
5.1 Are the data suitable for analysis?
  Yes, although a two by two table would have been useful.
5.2 Are the methods appropriate to the data?
  Yes, but more statistical analysis would have clarified clinical applicability. No confidence intervals were reported for test characteristics.
5.3 Are any statistics correctly performed and interpreted?
  Statistics were correctly performed, but the authors' interpretation is not entirely supported by their data.
6 Discussion
6.1 Are the results discussed in relation to existing knowledge on the subject and study objectives?
6.2 Is the discussion biased?
  Yes, by not calculating the number needed to treat (NNT) to detect treatable clinically silent TLFx, the authors underestimate the cost of screening with X-ray imaging.
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
  Unclear. Though their data suggest clinical examination is adequate to rule out LTFx requiring surgery, the authors choose to support imaging for all patients in their population. The reasons for their choice seem to rest on issues of study sample size and theoretical consequences of missed TLFx, but are not well delineated.
7.2 What level of evidence has this paper presented? (using CEBM levels )
  2B: an exploratory cohort study with good reference standards.
7.3 Does this paper help me answer my problem?
  Yes and No. This paper demonstrates clinically silent LTFx can be present in patients with slight alterations of mental status. However the practical relevance of this finding would be stronger if analysis also included the test statistics for detecting treatable LTFx.
After CA, i rated this paper: 5/10
8 Implementation
8.1 Can the test be implemented in practice?
  Yes as the test in question already employed universally.
8.2 What aids to implementation exist?
8.3 What barriers to implementation exist?
8.4 Are my patients the same as the patients tested?
8.5 Will the test improve diagnosis in my patients?
  No. However, this study does build confidence in the clinical exam of mildly altered patients. A larger, more rigorous study may clarify the need to rule out TLFx with X-ray imaging.