1. School of Medicine - Universidad de Valparaiso; Biomedical Research Centre; Valparaiso Chile
2. Iberoamerican Cochrane Network; Barcelona Spain
3. CIBER Epidemiología y Salud Pública (CIBERESP); Iberoamerican Cochrane Centre - Biomedical Research Institute Sant Pau (IIB Sant Pau); Sant Antoni Maria Claret, 167 Pavilion 18 (D-16a) Barcelona Catalonia Spain 08025
4. Iberoamerican Cochrane Centre - Biomedical Research Institute Sant Pau (IIB Sant Pau); C. Sant Antoni Maria Claret 171 Barcelona Catalunya Spain 08041
5. Hospital de la Santa Creu i Sant Pau; Department of Anesthesiology; Sant Antoni M. Claret 167 Barcelona Spain 08025