Inter-observer agreement on levels of evidence in radiology articles

Levels of evidence (LE) are established through a hierarchical classification of studies according to their design. At present, there are many heterogeneous LE classifications, and this hampers their applicability. Our study aims to identify which LE classification has the best interobserver concordance for radiology articles. For this purpose, an interobserver agreement analysis were performed on 105 original articles applying two NE scales (Oxford Center of Evidence Based Medicine (OCEBM) y National Health and Medical Research Council (NHMRC)). The inter-rater agreement of the LE assigned after reading the abstracts was good when using the OCEBM scale (K = 0.679), and somewhat lower with the NHMRC (K = 0.577 -moderate-). All differences were statistically significant (P < .000). So, in conclusion, of the two scales analysed (OCEBM and NHMRC), the OCEBM led to the strongest level of inter-rater agreement.