Mental health outcomes in frontline healthcare workers in Brazil during the COVID-19 epidemic: Results of an online survey in four regions using respondent-driven sampling (RDS) oleh Mírian Cohen, Ricardo B. Cardoso, Ligia R.F.S. Kerr, Carl Kendall, Rosa L.F. Almeida, Nayê B. Schneider, Carolina M. Viera, Jorge G. Zaduchliver, Andriele A. Castro, Francisco M.L. Pinheiro, Maria F.P.M. Albuquerque, Luana N.G.C. Lima, Maria A.S.M. Veras, Celina M.T. Martelli, Luciane N. Cruz, Suzi A. Camey