“And then when I talked to a nurse, matter of fact, he said, ‘Oh, that’s delirium, that’s pretty normal,’” Ennis said. Age is a risk factor, as delirium presents in about half of hospitalized patients ages 65 and older. “This patient has an estimated greater than 50 per cent risk of developing delirium. An Ottawa-based study in 2021 found a patient’s hospital stay can increase by almost a week and cost an additional $6,000. The delirium risk calculator is one of their projects and began with a research study of nearly 4,000 admissions at six Toronto area hospitals.