Prevalence and characteristics of polycystic ovary syndrome in Brazilian women: protocol for a nation-wide case–control study - Spritzer, Poli Mara; Marchesan, Lucas B.; Santos, Betânia R.; Cureau, Felipe V.; Oppermann, Karen; Reis, Rosana Maria dos; Ferriani, Rui Alberto; Weiss, Rita; Meirelles, Ricardo; Candido, Ana Lucia; Reis, Fernando Marcos dos (BMJ Open, 2019)