Does this type of surgery help obese patients? Which of these drugs should I prescribe for this patient? How effective was this policy change in reducing hospital readmissions? These types of questions, and more, are addressed by the mathematical framework of causal inference. Causal inference is a centerpiece of the type of methods used at the Clalit Research Institute, as well as in the field of epidemiology as a whole. At the Institute, we combine years of experience in causal study designs, with state-of-the-art methods that adapt machine learning tools to estimate causal effects. Much of this research-level work is done in close collaboration with leaders in academia.