A two-year study beginning in 1977 found that, among 85-year-old peopl

Why does (C) Some of the drugs that had been used to treat the symptoms of heart disease had a side effect of weakening the immune system solve the paradox?

If those people took these drugs, they should not die and got effect of weakening the immune system.

Dear GMATNinja

I have a trouble regarding this question
Question tells us that "those whose immune systems were weakest were twice as likely to die within two years as others in the study. The cause of their deaths, however, was more often heart disease than cancer or infections"

Here ı presume that "their" refers to the people at lowest immunity system strength spectrum. So, we understand that people with low immune systems are more likely to die but somehow more of them died due to heart attack than to infections...

Question asks us to identify the choice that may offer the best explanation that they died not because of weakness of the immune system

(A) There were twice as many infections among those in the study with the weakest immune systems as among those with the strongest immune systems.
If we say that people with the lowest immune system had more infections but still didn't die mostly to infections doesn't it solidify that weak immune system may not be the culprit? Because from the stem we know that majority cause for their death is heart attack but not infections

Which of the following, if true, would offer the best prospects for explaining deaths in which weakness of the immune system, though present, played no causal role?

(A) There were twice as many infections among those in the study with the weakest immune systems as among those with the strongest immune systems.

(C) Some of the drugs that had been used to treat the symptoms of heart disease had a side effect of weakening the immune system.

A two-year study beginning in 1977 found that, among 85-year-old people, those whose immune systems were weakest were twice as likely to die within two years as others in the study. The cause of their deaths, however, was more often heart disease, against which the immune system does not protect, than cancer or infections, which are attacked by the immune system.

Which of the following, if true, would offer the best prospects for explaining deaths in which weakness of the immune system, though present, played no causal role?

(C) Some of the drugs that had been used to treat the symptoms of heart disease had a side effect of weakening the immune system.

When you read the blue -

Do you comprehend that as saying

-- The STRONGER immune system, the lower likelihood of cancer/infections
-- The WEAKER immune system, the higher likelihood of cancer/infections

OR

Do you comprehend the blue as saying

-- There is some relationship between cancer/infections vs immune systems. But we cant say for sure -- The Stronger Immune system, the lower the likelihood of cancer/infections.

Same question on the red

When you read the red - Do you comprehend that as saying

-- There is NO relationship/correlation between heart disease vs immune systems.

OR

-- With a STRONG immune system, you could have heart disease or you could NOT have heart disease
-- With a WEAK immune system, you could have heart disease or you could NOT have heart disease

dear AVI avigutman
would you please clarify what two groups are compared? I am total confused after this thread.

I am not sure whether,
among those with weakest immune system, the death from heard disease are more than that from infections/cancers.
or
among the whole study, those with weakest immune system are twice likely to die than those with stronger immune system?
or
among the whole study, those with weakest immune system are more often dead from heart diseases than those with stronger immune system dead from infections/ cancers.

The cause of their deaths, however, was more often heart disease, against which the immune system does not protect, than cancer or infections, which are attacked by the immune system.

This is a paradox question and you have to explain the paradox.

- Those whose immune systems were weakest were twice as likely to die within two years as others in the study.
- But cause of their deaths was more often heart disease - something which has nothing to do with immune system

This is odd, right? If people with weak systems were the first to go, they should have gone due to some immune system related complication. But this is not so. They often died due to heart disease.

Let's look for an option that w ill explain this:

(A) There were twice as many infections among those in the study with the weakest immune systems as among those with the strongest immune systems.
If people with weak immune systems had many more infections (which makes sense), then it also makes sense that they will die due to those infections and not heart diseases. Hence, we do not get an explanation of the paradox.

(B) The majority of those in the study with the strongest immune systems died from infection or cancer by 1987.
How those with strongest immune systems died is out of scope.

(C) Some of the drugs that had been used to treat the symptoms of heart disease had a side effect of weakening the immune system.
This explains our paradox. If medicine for symptoms of heart disease causes weak immune system, it means that people with heart disease would have weak immune systems too. Perhaps those were the people that we identified with weak immune systems. They died due to heart disease is then understandable since they had heart disease (the medicine is symptomatic treatment only).

(D) Most of those in the study who survived beyond the two-year period had recovered from a serious infection sometime prior to 1978.
Out of scope. We are not worried about people who died after the two year period. We are worried about the cause of death of those who died within the two year period.

(E) Those in the study who survived into the 1980s had, in 1976, strengthened their immune systems through drug therapy.
Again, out of scope. Same reason as that of (D).

Answer (C)

I have a doubt regarding how the question is asked. The question says " would offer the best prospects for explaining deaths in which weakness of the immune system, though present, played no causal role ", especially the "played no casual role" part doesn't it mean that the question asks us to justify or prove that the weak immune system has had a major role in the death of those who died by heart attack? Because when reading the question I interpreted it as give a reason to justify that the cause of those deaths was the weak immune system and not the heart attack itself.

This is a paradox question and you have to explain the paradox.

- Those whose immune systems were weakest were twice as likely to die within two years as others in the study.
- But cause of their deaths was more often heart disease - something which has nothing to do with immune system

This is odd, right? If people with weak systems were the first to go, they should have gone due to some immune system related complication. But this is not so. They often died due to heart disease.

Let's look for an option that w ill explain this:

(A) There were twice as many infections among those in the study with the weakest immune systems as among those with the strongest immune systems.
If people with weak immune systems had many more infections (which makes sense), then it also makes sense that they will die due to those infections and not heart diseases. Hence, we do not get an explanation of the paradox.

(B) The majority of those in the study with the strongest immune systems died from infection or cancer by 1987.
How those with strongest immune systems died is out of scope.

(C) Some of the drugs that had been used to treat the symptoms of heart disease had a side effect of weakening the immune system.
This explains our paradox. If medicine for symptoms of heart disease causes weak immune system, it means that people with heart disease would have weak immune systems too. Perhaps those were the people that we identified with weak immune systems. They died due to heart disease is then understandable since they had heart disease (the medicine is symptomatic treatment only).

(D) Most of those in the study who survived beyond the two-year period had recovered from a serious infection sometime prior to 1978.
Out of scope. We are not worried about people who died after the two year period. We are worried about the cause of death of those who died within the two year period.

(E) Those in the study who survived into the 1980s had, in 1976, strengthened their immune systems through drug therapy.
Again, out of scope. Same reason as that of (D).

Answer (C)­