Topic Highlight
Copyright ©2014 Baishideng Publishing Group Co.
World J Orthop. Apr 18, 2014; 5(2): 89-93
Published online Apr 18, 2014. doi: 10.5312/wjo.v5.i2.89
Table 2 Levels of evidence
Evidence levelTherapeutic studies: Evaluating results of treatmentPrognostic studies: Evaluating outcome of disease
IRCTProspective study (> 80% follow-up)
Systematic review of level 1 RCTsSystematic review of level I studies
IIProspective cohort studyRetrospective study
Poor quality RCT (e.g., < 80% follow-up)Systematic review of level II studies
Systematic review of level III studies
IIICase control study
Retrospective cohort study
Systematic review of level III studies
IVCase seriesCase series
VExpert opinionExpert opinion