Critical appraisal (I): Fundamentals, tools, and application to scientific articles on outcomes and harmful effects Javier González de Dios; María Salomé Albi Rodríguez; Álvaro Gimeno Díaz de Atauri; Laura Cabrera Morente; Elena Pérez González; Carlos Ochoa Sangrador;

Evidence-based medicine: 5 steps to navigate uncertainty Rafael Martín-Masot; Carlos Ochoa Sangrador; Jaime Javier Cuervo Valdés; Carolina Blanco Rodríguez; Paz González Rodríguez; Javier González de Dios;

COVID-19: Critical appraisal of the evidence Paz González Rodríguez; Begoña Pérez-Moneo Agapito; María Salomé Albi Rodríguez; Pilar Aizpurua Galdeano; María Aparicio Rodrigo; María Mercedes Fernández Rodríguez; María Jesús Esparza Olcina; Carlos Ochoa Sangrador;