Two studies were carried out to determine if children in daycare got more ear infections than children who stayed at home.The first study compared ear infection rates in 50 Canadian girls ages 1 to 2,half of whom attended daycare and half of whom stayed home.The second study compared ear infection rates in 1000 Swedish boys ages 3 to 4,half of whom attended daycare and half of whom stayed home.The results of these two studies differed greatly.
Which of the following is LEAST likely to be the cause of such differences?

Question

Quizplus · Accepted Answer

The differences in the results of the studies are least likely to be caused by "different mothers" because the studies' outcomes are more likely influenced by factors such as age, gender, sample size, and country, which can directly affect health outcomes and exposure to infections, rather than the individual characteristics of the mothers.

Two Studies Were Carried Out to Determine If Children in Daycare