Bibliography (14):

1. https://jamanetwork.com/journals/jama/fullarticle/1895230

2. The unpredictability paradox: review of empirical comparisons of randomized and non-randomized clinical trials

3. Comparison of Evidence of Treatment Effects in Randomized and Nonrandomized Studies

4. Contradicted and Initially Stronger Effects in Highly Cited Clinical Research

5. Assessing treatment effects and publication bias across different specialties in medicine: a large empirical study of the Cochrane Database of Systematic Reviews

6. Agreement of treatment effects for mortality from routinely collected data and subsequent randomized trials: meta-epidemiological survey

7. Comparison of evidence on harms of medical interventions in randomized and nonrandomized studies

8. Interpreting the evidence: choosing between randomized and non-randomized studies

9. Wikipedia Bibliography:

   1. Meta-analysis

   2. Confidence interval

   3. https://en.wikipedia.org/wiki/Impact_factor  :

      https://en.wikipedia.org/wiki/Impact_factor

   4. Systematic review

   5. Randomized controlled trial

   6. https://en.wikipedia.org/wiki/Random_effects_model  :

      https://en.wikipedia.org/wiki/Random_effects_model