The following comparison of surgical procedures is taken from Charig et al. (1986). Two treatments are considered

Question:

The following comparison of surgical procedures is taken from Charig et al. (1986). Two treatments are considered for kidney stones, namely open surgery (abbreviated to OS) and percutaneous nephrolithotomy (PN). It is reported that OS has a success rate of 78% (= 273/350) and PN a success rate of 83% (= 289/350). This looks like a marginal advantage to PN. On looking more closely, the patients are divided into two groups depending on whether or not their stones are smaller than 2 cm, with the following success rates.

stone < 2 cm stone > 2 cm Total OS 93% (= 81/87) 73% (= 192/263) 78% (= 273/350)

PN 87% (= 234/270) 68% (= 55/80) 83% (= 289/350)

Fantastic news! We've Found the answer you've been seeking!

Step by Step Answer:

Related Book For  book-img-for-question

Probability An Introduction

ISBN: 9780198709978

2nd Edition

Authors: Geoffrey Grimmett, Dominic Welsh

Question Posted: