Intensive care unit staff preparedness as an independent factor for death of patients during COVID-19 pandemic: An observational cohort study Jaques Sztajnbok; Ana Freitas Ribeiro; Ceila Maria Sant Ana Malaque; Roberta Figueiredo Cavalin; Marina Pozzi Lanza; Nidyanara Francine Castanheira de Souza; Caroline Martins Rego; Paula Caroline Werlang Custodio; Renata Elisie Barbalho Siqueira; Jose Ernesto Vidal; Claudia Figueiredo-Mello;