Imagine a study of surgery survival rates in two hospitals: Hospital A and Hospital B. Surgery patients in these hospitals are classified as being in either good condition or poor condition. Which of...

Which is the correct answer? AP statistics


Extracted text: Imagine a study of surgery survival rates in two hospitals: Hospital A and Hospital B. Surgery patients in these hospitals are classified as being in either good condition or poor condition. Which of the following would be an example of Simpson's paradox? When looking separately at survival rates for each kind of patient (good condition and poor condition), Hospital B has lower rates than Hospital A for both kinds, and Hospital A has better doctors. When looking separately at survival rates among patients in good condition and in poor condition, Hospital B has higher rates for both groups. Yet when the two groups are combined, Hospital A has a higher rate. Hospitals A and B have the same survival rates for patients in poor condition and good condition, even though the conditions of the patients are different. The two kinds of patients confound the doctors, because Hospital A has a higher surgery survival rate overall due to some kind of lurking variable. However, Hospital B has a more rigorous research program. Doctors at both hospitals are confounded to a varying degree because of lurking surgery survivors.