Assessing the level of evidence in the orthopaedic literature, 2013–2018: a review of 3449 articles in leading orthopaedic journals

BACKGROUND: In biomedical research, level of evidence (LOE) indicates the quality of a study. Recent studies evaluating orthopaedic trauma literature between 1998 and 2013 have indicated that LOE in this field has improved. The objective of this study was to determine the validity of one such study by 1) comparing our results and how they relate to more recent years of publications; and 2) assessing how our findings may be used to estimate future changes. METHODS: A total of 3449 articles published from 2013 to 2018 in The Journal of Orthopaedic Trauma (JOT); Journal of Bone and Joint Surgery, American Volume (JBJS-Am); and Clinical Orthopaedics and Related Research (CORR) were evaluated for their LOE. Articles published in JBJS-Am or CORR were classified as trauma or nontrauma studies; articles published in JOT were considered trauma studies. Articles were assigned a LOE using guidance published by JBJS-Am in 2015. RESULTS: The percentage of total high-level (level I or II) trauma and nontrauma articles published in JOT, JBJS-Am, and CORR decreased from 2013 to 2018 (trauma 23.1 to 19.2%, p = 0.190; nontrauma 28.8 to 24.9%, p = 0.037). JBJS-Am published the highest percentage of level-I trauma studies, and CORR published the lowest percentage of level-IV studies. JBJS-Am and CORR published higher percentages of level-I trauma studies and lower percentages of level-IV nontrauma studies than all trauma studies. CONCLUSIONS: Based on our results we cannot validate the findings of previous studies as we found the overall LOE of both trauma and nontrauma orthopaedic literature has decreased in recent years. JBJS-Am published a greater percentage of high-level studies than did JOT and CORR. Although the number and percentage of high-level studies published in JOT increased during the study period, it still lagged behind JBJS-Am and CORR.