M. N. Wente, C. M. Seiler, W. Uhl, and M. W. Büchler, Perspectives of evidence-based surgery, Digestive Surgery, vol.20, issue.4, pp.263-269, 2003.

B. A. Jamjoom, A. A. Jamjoom, and A. B. Jamjoom, Level of evidence of clinical neurosurgery research in Saudi Arabia, Neurosciences, vol.19, issue.4, pp.334-337, 2014.

J. Howick, I. Chalmers, and P. Glasziou, The Oxford, 2011.

D. Moher, A. Liberati, J. Tetzlaff, and D. G. Altman, The PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement, Open Medicine, vol.3, issue.3, pp.123-130, 2009.

A. M. Makhdom, S. M. Alqahtani, K. A. Alsheikh, O. A. Samargandi, and N. Saran, Level of evidence of clinical orthopedic surgery research in Saudi Arabia, Saudi Medical Journal, vol.34, issue.4, pp.395-400, 2013.

R. Wupperman, R. Davis, and W. T. Obremskey, Level of evidence in Spine compared to other orthopedic journals, Spine, vol.32, issue.3, pp.388-393, 2007.

A. R. Amiri, K. Kanesalingam, S. Cro, and A. T. Casey, Level of evidence of clinical spinal research and its correlation with journal impact factor, Spine Journal, vol.13, issue.9, pp.1148-1153, 2013.

K. A. Aziz, T. Sallam, A. H. Ibrahim, and T. Sufian, Improvement of research and biomedical publication, Saudi Medical Journal, vol.25, issue.10, pp.1319-1322, 2004.

R. W. Poolman, P. A. Struijs, R. Krips, I. N. Sierevelt, K. H. Lutz et al., Does a "Level I Evidence" rating imply high quality of reporting in orthopaedic randomised controlled trials?, BMC Medical Research Methodology, vol.6, issue.44, 2006.

K. Alfaleh and S. Bajammal, Enhancing biomedical research in Saudi Arabia, Saudi Medical Journal, vol.26, issue.5, p.897, 2005.

C. Koutras, S. Antoniou, and H. Heep, Geographic origin of publications in major spine journals, Acta Orthopaedica Belgica, vol.80, issue.4, pp.508-514, 2014.