CASE STUDY 27.2 CRANBERRY JUICE AND BLADDER INFECTIONS

CASE STUDY 27.2
CRANBERRY JUICE AND BLADDER INFECTIONS
For Questions , use the following narrative
Narrative: Case study 27.2 summary
Researchers compared urinary bacteria levels of elderly women who drank 10 ounces of a juice drink containing cranberry juice each day to elderly women who consumed the same amount of a look-alike drink without cranberry juice (indistinguishable in taste, appearance, and vitamin C content from cranberry juice) .153 elderly women participated in this study.Each one was randomly assigned to the cranberry juice group or the placebo group and was followed over a 6-month period.The women had a mean age of 78.5 years and high levels of bacteria in their urine at the start of the study.The odds in the cranberry group of having bacteria levels exceeding a certain threshold were 42% of what they were in the control group.

-{Case study 27.2 narrative} Which negative effect was not being controlled for by using the placebo drink?

A) The placebo effect.
B) The interaction effect.
C) The experimenter effect.
D) All of the above were being controlled for with the placebo drink.