Operationalize the following research questions by translating them into SAS code, and analyze the results.

1. How many cases had a lens operation (ICD-9-CM operation code "13")? What was their mean age compared to other cases in the data set?

2. What proportion of cases seen in Winnipeg teaching hospitals were low-income (lowest income quintile)? How does this compare with the other hospitals? Label the values of the variables.

3. How many cases had a hip fracture (ICD-9-CM diagnosis code "820")? (Note that there are 2 diagnosis fields DIAG01 and DIAG02 that may pick up this code.) What proportion of these cases were transferred from another hospital? to another hospital? Label the values of the transfer variables.

4. How does the distribution of the 17 broad categories of ICD-9-CM (ICD17BRK) vary by: a) whether or not a high-risk diagnosis (CHARYES) was present? b) by gender? Label the values of the variables.

5. How many people in this sample died in total? How many died within 90 days of discharge?

An example program, log, and output are all available for the above questions. Note that the extra code in the PROC FREQ statements (formchar (1,2,7)='|-+') was needed to enable Web display of SAS- generated tables; otherwise, the lines in the table appear as character values.