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;

Frequency, risk and impact measures in epidemiology Carlos Ochoa Sangrador; Eduardo Ortega Páez; Manuel Molina Arias; Fernando Carvajal Encina; Eduardo Cuestas Montañes;

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;