When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because previous research found that this proportion of patients died.
若用于统计学总体，预后推估可以是非常准确的；比如，「严重败血性休克病人中，有45%会在28天内死亡」，这一判断有相当可信度，因为以前的研究发现死亡病人的比例是45%。