Hernán conducts research to learn what works to improve human health. Together with his collaborators from several countries, he designs analyses of healthcare databases, epidemiologic studies, and randomized trials. He is a Global Highly Cited Researcher.<ref name=":0">[https://recognition.webofsciencegroup.com/awards/highly-cited/2020/ Web of Science Highly Cited Researchers]</ref> His free edX course ''Causal Diagrams''<ref name=":1">[https://www.edx.org/course/causal-diagrams-draw-your-assumptions-before-your] edX Causal Diagrams course</ref> has had over 50,000 registrations. His book ''Causal Inference: What If'',<ref name=":2">Hernán MA, Robins JM (2020). ''Causal Inference: What If.'' Boca Raton: Chapman & Hall/CRC.[https://www.hsph.harvard.edu/miguel-hernan/causal-inference-book/]</ref> co-authored with [[James Robins]] is also freely available online and widely used for the training of researchers. | Hernán conducts research to learn what works to improve human health. Together with his collaborators from several countries, he designs analyses of healthcare databases, epidemiologic studies, and randomized trials. He is a Global Highly Cited Researcher.<ref name=":0">[https://recognition.webofsciencegroup.com/awards/highly-cited/2020/ Web of Science Highly Cited Researchers]</ref> His free edX course ''Causal Diagrams''<ref name=":1">[https://www.edx.org/course/causal-diagrams-draw-your-assumptions-before-your] edX Causal Diagrams course</ref> has had over 50,000 registrations. His book ''Causal Inference: What If'',<ref name=":2">Hernán MA, Robins JM (2020). ''Causal Inference: What If.'' Boca Raton: Chapman & Hall/CRC.[https://www.hsph.harvard.edu/miguel-hernan/causal-inference-book/]</ref> co-authored with [[James Robins]] is also freely available online and widely used for the training of researchers. |