Increase in quality and quantity of orthopaedic studies from 2002 to 2012

To compare the level of evidence of orthopaedic studies published in 2002 and 2012 to determine whether the quality and quantity of studies have increased.

The top 10 orthopaedic journals in 2002 and 2012 were identified, according to the Thomson Reuters impact factor. The level of evidence of each clinical article between January and June in 2002 and 2012 were determined by 2 senior orthopaedic trainees, according to the Oxford Centre for Evidence-based Medicine 2011 Levels of Evidence. Basic science articles, case reports, and non-systematic reviews were excluded. The proportions of papers designated to each level of evidence in 2002 and 2012 were compared, as was the mean level of evidence of studies in 2002 and 2012.

In 2002, 379 clinical articles were identified and their level of evidence was level 1 (n=3), level 2 (n=67), level 3 (n=71), and level 4 (n=238). In 2012, 642 clinical articles were identified and their level of evidence was level 1 (n=26), level 2 (n=113), level 3 (n=167), and level 4 (n=336). The proportion of level 4 articles decreased from 62.8% in 2002 to 52.3% in 2012 (p=0.001), whereas the proportion of level 1 articles increased from 0.8% to 4.1% (p=0.002) and level 3 articles increased from 18.7% to 26.0% (p=0.008). The mean level of evidence improved from 3.44 in 2002 to 3.27 in 2012 (p=0.002).

The quality and quantity of orthopaedic studies have increased from 2002 to 2012, but most studies remained of a low level of evidence.