Journal Club Summary

Methodology Score: 3/5                 
Usefulness Score:  3/5
Authors: Rodriguez RM, et al. PLoS Med. 2015 Oct 6;12(10):e1001883.
This study derived and validated a clinical decision rule for CT imaging in blunt thoracic trauma (NEXUS CT Chest rule) that was found to have a sensitivity of 99.2% for “major injury” and 95.4% for “major and minor injury” and a specificity of 25.5% and 31.7% respectively. This study had certain methodological flaws such as including patients with GCS<15 and including independent variables open to interpretation (ex: distracting injury) but does serve to illuminate historical and physical exam findings predictive of significant thoracic injury.
By: Dr. Simeon Mitchell

Epi lesson:

Critical appraisal criteria for a paper that validates an existing decision rule are different than those for a study that derives or creates the rule. Most important is that the study evaluates the existing rule accurately and explicitly such that the physicians using it are adequately instructed. Some studies do a validation from an existing database but we believe that it is far better to conduct a prospective real-time validation by clinicians.