Could you please show me the details Not just answers A stud
Could you please show me the details? Not just answers
A study compared the cucceess rates of two different procedures
 for removing kidney stones: open surgery and percutaneous nephrolithotomy
 (PCNL), a minimally invasive technique.
 The number of procedures that were successful or not at getting rid of patients\'
 kidney stones for each type of procedure is shown in the tables below. A separate
 table is given for patients with small kidney stones and for patients with large
 stones.
                                     Procedure
                      Open surgery       PCNL
 Success               81                234
 Failure                  6                   36
 Table 1: Small stones.
                                    Procedure
                    Open surgery    PCNL
 Success            192                  55
 Failure                71                   25
 Table 2: Large stones.
 (a) (1 mark) Calculate the sample odds ratio of a successful kidney stone
 removal for each of the tables (Table 2 and Table 3).
 
 (b) (1 mark) Obtain a 95% CI for the odds ratio of a successful kidney stone
 removal when the stones are large.
 (c) (1 mark) Combine both tables into a pooled table in which the size of the
 stones is not relevant and display it.
 (d) (1 mark) Calculate the sample odds ratio for your table in part c).
 (e) (1 mark) Compare the sample odds ratio that you calculated in part d)
 with the ones you had calculated in part a). Did anything unexpected
 happen with the sample odds ratio once you combined the two separate
 tables into one? What is the name of this phenomenon?
 (f) (3 marks) Test the homogeneity of odds ratios of a successful kidney stone
 removal over the two di erent procedures of removal at the signi cance
 level 0.05. Show all steps.
 (g) (1 mark) Calculate the common odds ratio of a successful kidney stone
 removal adjusted by stone size.
 (h) (2 marks) Construct a 95% CI for the common odds ratio of a successful
 kidney stone removal adjusted by stone size.
 (i) (3 marks) Test whether there is an association between success of kidney
 stone removal and procedure, adjusted by stone size. Show all steps.
Solution

