Observational studies generally match RCTs well:
Cochrane systematic MA of reviews themselves systematically reviewing observational vs RCTs found no significant diff in effect size: https://t.co/LFVmfTwWer
pooled ROR effect f/ RCTs v observational studies: 1.08, 95% CI 0.96-1.22 https://t.co/KqDj5YVYVS

— Karl Pfleger (@KarlPfleger) August 9, 2022