Please answer the following questions after carefully reading the paper:

Bedair, H., Ting, N., Bozic, K.J., Della Valle, C.J., Sporer, S.M. (2011) Treatment of Early Postoperative Infections after THA - A Decision Analysis, Clinical Orthopaedics and Related Research, 469:34773485.

a) What kind of model was developed? What was the aim(s) of the model?

b) Briefly describe the possible decision alternatives, outcomes, and criterion for selecting the best decision.

c) Using a suitable package such as Precision Tree, draw, for this problem, a decision tree such as the one in Figure 1. Include all relevant parameters.

d) Fold back the tree and determine the best option. Is it the same as in the paper? Justify why or why not.

e) Undertake the same one-way and two-way sensitivity analyses as in the paper, as well as any additional sensitivity analysis as you see fit (justify). You might use graphics of your choice to display results. Comment on your results, in particular on: - how they compare with those in the paper - the usefulness of sensitivity analysis in decision analysis.