Researchers analyzed records of hospitalization for heart disease in two Ohio cities,Bowling Green and Kent.A city ordinance enacted in Bowling Green banned smoking in public areas.Results indicated that hospitalization rates for the two cities were similar before the smoking ban,but hospitalization rates decreased in Bowling Green compared to Kent following the smoking ban.A potential threat to internal validity that will need to be ruled out is
A) the amount of information about heart disease presented in national media.
B) changes in the state sales tax on cigarettes.
C) changes in doctors' focus on symptoms of heart disease in Bowling Green (because of publicity for the ban), but not in Kent.
D) all of these

Question

Quizplus · Accepted Answer

This potential threat to internal validity refers to the possibility that the smoking ban may have influenced doctors in Bowling Green to be more vigilant in detecting and treating symptoms of heart disease, leading to an apparent decrease in hospitalization rates. This could create a spurious relationship between the smoking ban and the reduced hospitalization rates, and therefore needs to be ruled out as a potential confound. The other potential threats (amount of information about heart disease presented in national media and changes in state sales tax on cigarettes) are not directly related to the smoking ban and are therefore not as likely to affect the results.

Researchers Analyzed Records of Hospitalization for Heart Disease in Two