1 Research Department. Instituto Universitario del Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
2 Interdisciplinary Centre for Health Studies (CIESAL), Universidad de Valparaíso, Cochrane Chile Associate Centre, Viña del Mar, Chile.
3 Interdisciplinary Centre for Health Studies (CIESAL), Universidad de Valparaíso, Cochrane Chile Associate Centre, Viña del Mar, Chile nicolas.meza@uv.cl.