Evidence-Based Practice and Critical Literature Review
Evidence hierarchy
Understand the hierarchy of evidence: systematic reviews and meta-analyses, randomized controlled trials, cohort and case-control studies, case series, and expert opinion. Know the strengths and limitations of each and the difference between efficacy and effectiveness. Understand the role of bias, confounding, and chance in interpreting studies.
Appraisal skills
Know how to appraise a study: research question, design, sample size and power, randomization, blinding, outcome measures, and statistical significance versus clinical significance. Understand confidence intervals, p-values, and effect sizes, and know why a statistically significant result may not be clinically meaningful.
Traps
Questions often test whether you can identify a flawed design or an inappropriate conclusion, or whether you know that a systematic review of poor-quality studies is still weak evidence. Another trap is confusing correlation with causation.
Worked example
A study reports that a new appliance reduces treatment time by 2 weeks with a p-value of 0.04. Rule of thumb: check the confidence interval and effect size - a small, statistically significant difference may not justify the cost or risk.