Figure 1

The Markov state transition diagram for each of five different vaccination program strategies. During each one year cycle, well patients could acquire influenza, invasive pneumococcal disease or both and subsequently either recover, become disabled or die. All patients ended each one year cycle in one of the following three health states: well, disabled or dead. Patients in the well and disabled states could also die based on all-cause and disability-associated mortality. The only differences between the no program and the four different vaccination program strategies are the cost of the vaccination program and the probability of receiving influenza and pneumococcal polysaccharide vaccination.