Critical Reasoning

Several studies have shown that hospitals are not all equally successful: patients are much more likely to die in some of them than in others. Since the hospitals in the studies had approximately equal per-patient funding, differences in the quality of care provided by hospital staff are probably responsible for the differences in mortality rates.

Which one of the following, if true, casts the most doubt on the conclusion drawn above?


(A) The staff in some of the hospitals studied had earned more advanced degrees, on average, than the staff in the other hospitals.

(B) Patient populations vary substantially in average severity of illness from hospital to hospital.

(C) The average number of years that staff members stay on at a given job varies considerably from one hospital to another.

(D) Approximately the same surgical procedures were performed in each of the hospitals covered in the studies.

(E) Mortality rates for hospital patients do not vary considerably from one region of the country to another.

newton9 wrote:Several studies have shown that hospitals are not all equally successful: patients are much more likely to die in some of them than in others. Since the hospitals in the studies had approximately equal per-patient funding, differences in the quality of care provided by hospital staff are probably responsible for the differences in mortality rates.

Which one of the following, if true, casts the most doubt on the conclusion drawn above?


(A) The staff in some of the hospitals studied had earned more advanced degrees, on average, than the staff in the other hospitals.

(B) Patient populations vary substantially in average severity of illness from hospital to hospital.

(C) The average number of years that staff members stay on at a given job varies considerably from one hospital to another.

(D) Approximately the same surgical procedures were performed in each of the hospitals covered in the studies.

(E) Mortality rates for hospital patients do not vary considerably from one region of the country to another.

IMO B

+1 for B

B for me!

IMO B. What is the OA?

IMO : B

my take option B

my first answer was A.
But after reading the question once more, I realized that the issue was not the staff but the patients
So B sounds ok.

My 2 cents:
It is false to generalize "The higher the mortality rate, the worse the hospital" because "rate" can not tell the whole story and the reality behind it. For the fact that, some hospitals substantially have greater number of patients than others do.

Lets talk with numbers:

International Hospital :Mortaliy Rate 60%, Number of people die: 10.000
Local Hospital : Mortaliy Rate 90%, Number of people die: 1000

So it is obvious that the higher the mortality rate never means the worse the hospital...

Alternate cause should be sufficient to weaken the conclusion in this question. Option B does the same

Option B is correct.
It provides an alternate cause for the difference in rate of death
The argument states that Lack of care is the reason

But B states that the severity of illness at diff. hospitals could have been the reason behind the findings.....

If you like my explanation please press the "Thank" Button

Maddie is correct. This is a quintessential reasoning flaw that is employed by Weakening or Assumption questions. If X and Y occur together, then X caused Y (or vice versa). So if X doesn't happen then Y is also not going to happen.
The best way to tackle these questions is notice this kind of reasoning. For weakening we need to just bring an additional info that Y is not solely dependent on X but a lot of other factors too.

Thanks
Prashant