Morris, TP; van Smeden, M; (2022) Causal analyses of existing databases: The importance of understanding what can be achieved with your data before analysis (commentary on HernĂ¡n). Journal of Clinical Epidemiology , 142 pp. 261-283. 10.1016/j.jclinepi.2021.09.026 <https://doi.org/10.1016/j.jclinepi.2021.09.026>. Green open access