“…Only 2 pairs of studies [30/32 and 41/44] used well-defined criteria, from which the most adequate ones were chosen for further examination [30,44]. Six studies that used selected patient samples or samples gathered both retrospectively and prospectively were excluded [15,21,24,29,47,56]. This yielded a total of 16 prospective [6,10,17,19,22,23,30,33,36,39,40,42,44,45,53,55] and 3 retrospective [8,40,46] studies for further research and analysis of the overall incidence of postcardiotomy delirium and possible risk factors.…”