Applying two approaches to detect unmeasured confounding due to time-varying variables in a self-controlled risk interval design evaluating COVID-19 vaccine safety signals, using myocarditis as a case example - Sophie H Bots; Svetlana Belitser; Rolf H H Groenwold; Carlos E Durán; Judit Riera-Arnau; Anna Schultze; Davide Messina; Elena Segundo; Ian Douglas; Juan José Carreras; Patricia Garcia-Poza; Rosa Gini; et al. (American Journal of Epidemiology, 2024)