Concept explainers
At one time, a method called “gastric freezing” was used to treat people with peptic ulcers. An inflatable bladder was inserted down the esophagus and into the stomach, and then a cold liquid was pumped into the bladder. Now you can find the following notice on the Internet site of a major insurance company:
[Our company] does not cover gastric freezing (intragastric hypothermia) for chronic peptic ulcer disease… .
Gastric freezing for chronic peptic ulcer disease is a non-surgical treatment which was popular about 20 years ago but now is seldom performed. It has been abandoned due to a high complication rate, only temporary improvement experienced by patients, and a lack of effectiveness when tested by double-blind, controlled clinical trials.
What did that “controlled clinical trial” (experiment) probably look like? (Don’t worry about “double-blind”; we’ll get to that soon.)
- a) What was the factor in this experiment?
- b) What was the response variable?
- c) What were the treatments?
- d) How did researchers decide which subjects received which treatment?
- e) Were the results statistically significant?
Want to see the full answer?
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Intro Stats
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