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Chapter 4: Q 63. (page 255)

Treating prostate disease A large study used records from Canada’s national health care system to compare the effectiveness of two ways to treat prostate

disease. The two treatments are traditional surgery and a new method that does not require surgery. The records described many patients whose doctors had

chosen each method. The study found that patients treated by the new method were significantly more likely to die within eight years.

(a) Further study of the data showed that this conclusion was wrong. The extra deaths among patients who got the new method could be explained by lurking variables. What lurking variables might be confounded with a doctor’s choice of surgical or nonsurgical treatment?

(b) You have 300prostate patients who are willing to serve as subjects in an experiment to compare the two methods. Write a few sentences describing how you would design this experiment.

Short Answer

Expert verified

(a) The lurking variables here are cost, patient's health, no possibility of survival.

(b) Divide patients into two groups and allow traditional procedure to one patient and modern method to other. Conclude the result.

Step by step solution

01

Given Information

Two treatments were given to the patients, one traditional method and one modern without surgery. The study found that patients treated by the new method were significantly more likely to die within eight years.

02

To determine lurking variables may be misunderstood for surgical and treatment without surgery.

The lurking variable has major effect, but it is not an indicator. It may be omitted if its presence is unclear. Because of it, patient may be bad state and less chances of survival. As a result may not suggest surgery and prefer non operative means.

Cost, health are other lurking variables.

03

To elaborate how to plan experiment

  • Assign two groups of 150each to the patients randomly.
  • Give one group traditional treatment and other modern treatment.
  • Measure the number of patients survived without surgery in two groups.

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Most popular questions from this chapter

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