Figure 1.

Illustration of how the ORs for developing POD change with age and duration of surgery, which was the primary hypothesis. The odds for a patient being 60 years of age and undergoing surgery for about 60 minutes were defined as baseline, i.e. OR=1. One can see that the risk for a 60-year-old patient being exposed to 600 minutes of surgery equals the risk of a 85-year-old patient undergoing 120 minutes of surgery (both OR=1.7). The risk increases exponentially with age and duration of surgery.