Treatment of breast cancer is a controversial issue with treatment varying from radical mastectomy to radiation and chemotherapy combined with simple lumpectomy. One long-term study involved noting survival times of all breast cancer patients from over 100 hospitals and comparing the percentage of women still alive 5 years after radical mastectomies with the percentage of women still alive 5 years after radiation and chemotherapy combined with simple lumpectomy. The results seems to show a better outcome for women who received lumpectomy treatment. Which of the following statements are appropriate?
I. This appears to be a well-conducted controlled experiment.
II. This observational study should be faulted for a lack of blinding.
III. A lurking variable involving who received what treatment makes any conclusion suspect.
A) I only
B) II only
C) III only
D) I and II
E) II and III
Answer: III only
If the answers is incorrect or not given, you can answer the above question in the comment box. If the answers is incorrect or not given, you can answer the above question in the comment box.