Risk factors, e.g. smoke and inactivity, affect quality of life and life expectation of people who are exposed to such risks. Prevention measures may impact on the exposition to risk factor, and therefore on their negative effects. In this thesis we build a model that simulate the evolution of a population subject to a risk factor and analyse the effects of public health policies on diseases related to the risk factor. In particular, the smoking risk factor and 4 diseases that are strongly correlated with smoke are taken into account. To measure the impact of the 4 diseases, we use two indicators of the disability burden induced by a disease, i.e.