> "The level of cognitive underperformance was also associated with the level of illness severity, with those who were hospitalized on a ventilator showing the greatest deficits."<p>If this is true then the medical treatment needs to be analyzed as well. The point being, in extreme cases perhaps the medicines and procedures do some harm in the process of treating the patient.<p>For example, my father had a stoke and was on a respiratory for a week. The tube down his throat led to a lung infection. That meant antibiotics and so on.