Garcia (Hospital de Montilla); Xos�� Luis P��rez (Hospital Universitario de Bellvitge); Nieves Garcia (Hospital Universitario La Princesa); Juan Carlos Ruiz, Jes��s Caballero, Esther Francisco, Tania Requena, Adolfo Ruiz, Jos�� Luis B��veda (Hospital Universitari Vall Hebr��n); Jos�� Miguel Soto, Constantino Tormo (Hospital Universitario Dr Peset); Rafael Blancas (Hospital La Mancha-Centro); Manuel Quintana, Miguel ��ngel Taberna (Hospital Nuestra Sra del Prado); Jose Maria A?on, Juan B. Aranjo (Hospital Virgen de la Luz); Manuel Rodr��guez (Hospital Juan Ramon Jim��nez); Jos�� Maria Garcia (Hospital La Serrania de Ronda); Ma Isabel Rodr��guez (Hospital General de Baza); Ma Jes��s Huertos (Hospital Universitario Puerto Real); Carlos Ortiz (Hospital Virgen del Rocio); Ma Eugenia Yuste (Hospital Universitario San Cecilio); Juan Francisco Machado (Hospital Santa Ana-Motril); Dolores Oca?a (Hospital La Inmaculada); Ram��n Vegas (Hospital Valle de los Pedroches); and Luis Vallejo (Hospital SAS La Linea).
The present study used data in an endemic setting from three medical and/or surgical centers of the multicenter prospective cohort OUTCOMEREA?, with homogeneous procedures for microbiological diagnosis of CDI. Patients were included between January 1999 and January 2009. ICU-acquired CDI was defined as watery or unformed stools, according to the Bristol stool chart [9], in a 24-hour period occurring �� 72 hours after ICU admission with a laboratory confirmation of a stool sample positive for C. difficile toxin A or B by an immunoassay enzyme [10]. Two control groups were chosen, the first including patients hospitalized at the same time in the same unit with watery or unformed stools in a 24-hour period occurring > 72 hours after ICU admission, but with a stool sample negative for C. difficile toxin A or B and a negative stool culture. The second one comprised patients hospitalized at the same time and the same unit.