A prognostic model for use before elective surgery to estimate the risk of postoperative pulmonary complications (GSU-Pulmonary Score): a development and validation study in three international cohorts - Santos, Roberto Cardoso Cardoso dos; Duarte, Geraldo; Joviliano, Edwaldo Edner; Santos, Carolina Lourenço Gomes dos; Quintana, Silvana Maria; Tamashiro, Edwin; Valera, Fabiana Cardoso Pereira; Zaccaro, Marília Veccechi Bijos; Salgado Júnior, Wilson (The Lancet Digital Health, 2024)