1. Cristóbal Cuadrado, Francisca Vidal, Jorge Pacheco, and Sandra Flores-Alvarado are with Escuela de Salud Pública, Universidad de Chile, Independencia, Región Metropolitana, Chile. Cristóbal Cuadrado is also with the Centre for Health Economics, University of York, York, UK. Jorge Pacheco is also with Facultad de Medicina, Universidad de Concepción, Concepción, Chile.