A study In Finland reported In Reuters on 61098 857 healthy

A study In Finland reported In Reuters on 6/10/98 857 healthy children In day-care centres were randomly given Xylitol In syrup, chewing gum or lozenge form, or a placebo gum or syrup In 5 doses per day over 3 months. The Incidence of ear infections In those children was noted. It was reported that the Incidence of ear Infections was reduced 40% in children given the Xylitol chewing gum, 30% by those given the Xylitol syrup and 20% In those given the Xylitol lozenges when compared to children given the placebo. Is this an observational study or an experiment? Why? What are the explanatory and response variables? Are confounding variables likely to be a problem In this study? Explain. Can these results be extended to all children? Give reasons for your answer

Solution

It is an experimental study not observational.

---------------------

Treatment is the explanatory variable and incidence of ear infection is respinse variable.

----------------------

May or may not. Most probably not beacuse the children are randomly selected.

--------------

Yes. becuase children are randomly selected from whole population (I am assuming that all children go to day care center).