Table 3.
Class of Evidence for Therapeutic Studies.
| Methodological Principle | Wu et al (2013)8 | Li et al (2014)9 |
|---|---|---|
| Study design | ||
| Prospective cohort study | ||
| Retrospective cohort study | ✓ | ✓ |
| Case-control study | ||
| Case-series | ||
| Independent or blind assessment | ||
| Co-interventions applied equally | ||
| Complete follow-up of ≥80% | ✓ | ✓ |
| Adequate sample size | ✓ | |
| Controlling for possible confoundinga | ✓ | |
| Moderately high risk | Moderately high risk |
aGroups must have comparable baseline characteristics or analysis must control for confounding.