Objectives and hypotheses
Are the objectives of the study clearly stated?
Yes- to examine the incidence and spectrum of spine injury in patients who are younger than 18 and to evaluate the efficacy of the NEXUS decision instrument for obtaining cervical spine radiography in paediatric trauma victims
Is the study design suitable for the objectives?
Yes- it is a prospective (with the advantage this design offers) cohort study
Who / what was studied?
3065 children with suspected cervical injury admitted to multiple centres were used to evaluate the efficacy of the NEXUS instrument for obtaining cervical radiography in children with suspected CSI
Was a control group used if appropriate?
Were outcomes defined at the start of the study?
Yes, children were defined as high- or low- risk according to the NEXUS criteria and the efficacy of this process for excluding c-spine injury was evaluated
Was this the right sample to answer the objectives?
Yes, the sample was made up of children aged 0-18 with acute trauma with suspected cervical injury selected for radiographic imaging. The sample was taken from multiple centres.
Is the study large enough to achieve its objectives? Have sample size estimates been performed?
The study is relatively large compared with other paediatric studies, but the sample is still small to draw definitive conclusions, especially for children younger than 9.
Were all subjects accounted for?
No patient who received radiographs was excluded from the study
Were all appropriate outcomes considered?
Yes, low risk with or without CSI and High risk with or without CSI
Has ethical approval been obtained if appropriate?
Not stated- informed consent obtained
Measurement and observation
Is it clear what was measured, how it was measured and what the outcomes were?
The authors made it clear as to what was measured (1. middle cervical tenderness, 2. painful distracting injury, 3. altered alertness, 4. neurological deficit and 5. intoxication). Although it was stated how they were recorded (questionnaire), details were not given in the paper of what was considered painful distracting injury or of the exact criteria used to define the presence of each of the 5 measurements. CSI was confirmed or rejected radiologically
Was the assessment of outcomes blinded?
Yes, the radiologists examining radiographs of the children were not aware of the high- or low-risk grouping of the child.
Was follow up sufficiently long and complete?
Not appropriate in this case, as all children had radiography and CSI was either confirmed or rejected
Are the measurements valid?
Yes, the NEXUS criteria have been tested on adults with success in the original NEXUS study. Radiology is of no questionable validity
Are the measurements reliable?
In most yes, but for some of the 5 NEXUS criteria the authors did not go into detail in this paper of how they assessed the patients
Are the measurements reproducible?
Not all measurements may be reproducible due to the low detail given by the authors.
Presentation of results
Are the basic data adequately described?
Yes, the data were well-presented on graphs and tables and well-described in the text.
Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
Although the results were described in detail, they were not very objective as the authors did not give emphasis to the fact that the specificity of their low-risk criteria for the exclusion of c-spine injury was only 19.8%
How large are the effects within a specified time?
Are the results internally consistent, i.e. do the numbers add up properly?
Yes, all numbers add up correctly
Are the data suitable for analysis?
The large number of data allowed statistical analysis, although the low number of children with actual CSI gave rise to a wide confidence interval for sensitivity
Are the methods appropriate to the data?
The exact methods of analysis were not stated
Are any statistics correctly performed and interpreted?
Methods not stated
Are the results discussed in relation to existing knowledge on the subject and study objectives?
Yes, the discussion covered existing knowledge and the relation with the results of this study, and found no conflict
Is the discussion biased?
The discussion is slightly biased in favour of the NEXUS criteria, but that does not mean that the evidence was not supportive
Are the author's conclusions justified by the data?
Yes, the conclusions were justified, but as the authors stated, care should be taken when applying the NEXUS criteria, as the available evidence is still not very strong, especially for children under 9.
What level of evidence has this paper presented? (using CEBM levels)
Class II evidence
Does this paper help me to answer my problem?
Yes, it was very helpful in helping with the decision to obtain radiographs of the cervical spine in children with suspected CSI.
Can any necessary change be implemented in practice?
The NEXUS criteria may be implemented into practice for children over 9, but a recent revier provided slightly different guidelines that include all 5 NEXUS criteria. See Neurosurgery 2002;50:S85-S99
What aids to implementation exist?
The current lack of guidelines (also a more recent review included the 5 NEXUS criteria into suggested guidelines)
What barriers to implementation exist?
Fear by the physician of missing a cervical injury, still insufficient evidence
Are the study patients similar to your own?
Does the paper give any conclusions that will affect what you will offer or tell your patient?
It suggests that children over 9 who meet the 5 NEXUS criteria should not have cervical radiography