1: Construct a simple Multi-Morbidity Index. Assess the average severity of CHF, MI, Diabetes, Hypertension, Alcohol Use, and ACL surgery (assume that sicker patients have longer stays). To calculate the average severity associated with a disease, compare all cases with the disease to all control patients without the disease. Make sure that in each comparison, patients with and without disease have the same set of comorbidities. For example, to find the average length of stay for patients with MI, select all MI patients with the following comorbidities: CHF,DM,AA. Then compare these cases to controls who do not have MI but have the same comorbidities. To help you understand this assignment, consider the following table. In this table, we see different strata of mutually exclusive and exhaustive comorbidities. Then, within each strata we can observe the impact of MI. The impact of MI is the average impact of MI within each strata. Your objective is to create this table before you calculate the impact of MI. To do so, first estimate n1 through n5 through a file where the data is restricted to cases with MI (WHERE MI=1). Then, estimate the values n6 through n10 through a file where the data are restricted to non-MI patients (WHERE MI=0). Merge these data, making sure that you match on the strata. Then you can calculate the impact of MI