Critical Reasoning

There is a great deal of geographical variation in the frequency of many surgical procedures - up to tenfold variation per hundred thousand people among different areas in the numbers of hysterectomies, prostatectomies and tonsillectomies.

To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following?

a. A local board of review at each hospital examines the records of each operation to determine whether the surgical procedure was necessary

b. The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered

c. There are several categories of surgical procedures that are often performed unnecessarily

d. For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or weather alternative treatment would have succeeded

e. With respect to how often the are performed unnecessarily, hysterectomies, prostatectomies, and tonsillectomies are respective of surgical procedures in general

a. A local board of review at each hospital examines the records of each operation to determine whether the surgical procedure was necessary
Does not support

b. The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered
Out of scope

c. There are several categories of surgical procedures that are often performed unnecessarily
Too general

d. For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or weather alternative treatment would have succeeded
Right answer - supports the conclusion

e. With respect to how often the are performed unnecessarily, hysterectomies, prostatectomies, and tonsillectomies are respective of surgical procedures in general
Don't even know what this implies

The answer must be B.

The passage tells us that certain surgeries occur at differential rates across different regions. We need to find a choice that supports the conclusion that this difference in rates is not indicative of certain surgeries being performed unnecesarily.

So before approaching the answer choices, you should ask yourself: what other factor could account for the difference in rates? Then, you should answer yourself: maybe certain diseases occur more frequently in certain places.

Choice B matches this insight.

While choice d is tempting, it would fail to explain why these surgical procedures occur at different rates.

I am not convinced at all. Can someone please explain why B is correct?

According to me we need to find a choice which says that the variations are indeed due to unnecesary surgical procedures.

Thanks

Radium - let's break this down.

This is from the OG 10 edition.

This is a special type of the strengthen question where the conclusion is in the question stem. Please be on the lookout for this as it occurs fairly regularly.

The conclusion is "much of the variation is due to unnecessary surgical procedures" This indicates a cause and effect relationship. We are, in effect, saying that the reason that there is a geographical variation in the listed procedures is because in the areas where more procedures are performed many of those procedures are not necessary.

Now there could be other reasons for a variation in the number of surgeries. For example, the new natural gas wells that are being drilled in people's back yards have been proven to contaminate the water supply and so it would be very reasonable to see additional cases of cancer and therefore additional procedures near these poisonous wells. So that would be another cause not unnecessary procedures, but variations in the toxicity of various places around the U.S. (or the world depending on how you read the question).

In order to strengthen a question that involves cause and effect, you will want to consider the possibility of blocking an alternate cause. In this case we are saying the cause is the "unnecessary procedures" so we want to block the things that would make these procedures necessary - like variations in the age of the population, the health of the people, the quality of the water, even the ability of the people to pay for the procedures.

Answer Choice B does this. It says, "The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered." So this blocks the idea that the cause of varying rates of procedures would be any of the factors (age, health, toxins) etc. mentioned above. So we strengthen one cause by blocking another.

Does that help you to think of approaching questions that feature a cause and an effect?

Sure it does...thanks a lot David.

Thanks for your explanation David.
Would it be possible for you to give us a few of these questions for practice and see if we can apply your method?

Thanks once again!

Very good explanation from David.

The variation is unrelated to factors--other than the surgical procedures themselves--that influence the incidence of diseases for which surgery might be considered.

So, surgery is done based on unrelated factors of diseases. Hence it is unnecessary.

Nice explanation David.

It worked for me.

Hi Verbal Experts - could you please share your DETAILED analysis for this CR ?

Much thanks!

Hi David can you tell me why option E is wrong.

David@VeritasPrep wrote:Radium - let's break this down.

This is from the OG 10 edition.

This is a special type of the strengthen question where the conclusion is in the question stem. Please be on the lookout for this as it occurs fairly regularly.

The conclusion is "much of the variation is due to unnecessary surgical procedures" This indicates a cause and effect relationship. We are, in effect, saying that the reason that there is a geographical variation in the listed procedures is because in the areas where more procedures are performed many of those procedures are not necessary.

Now there could be other reasons for a variation in the number of surgeries. For example, the new natural gas wells that are being drilled in people's back yards have been proven to contaminate the water supply and so it would be very reasonable to see additional cases of cancer and therefore additional procedures near these poisonous wells. So that would be another cause not unnecessary procedures, but variations in the toxicity of various places around the U.S. (or the world depending on how you read the question).

In order to strengthen a question that involves cause and effect, you will want to consider the possibility of blocking an alternate cause. In this case we are saying the cause is the "unnecessary procedures" so we want to block the things that would make these procedures necessary - like variations in the age of the population, the health of the people, the quality of the water, even the ability of the people to pay for the procedures.

Answer Choice B does this. It says, "The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered." So this blocks the idea that the cause of varying rates of procedures would be any of the factors (age, health, toxins) etc. mentioned above. So we strengthen one cause by blocking another.

Does that help you to think of approaching questions that feature a cause and an effect?