Do ethnic group and gender influence the type of care that a heart patient receives? The following passage is from the article “Heart Care Reflects Race and Sex, Not Symptoms” (USA Today, February 25, 1999): Previous research suggested blacks and women were less likely than whites and men to get cardiac catheterization or coronary bypass surgery for chest pain or a heart attack. Scientists blamed differences in illness severity, insurance coverage, patient preference, and health care access. The researchers eliminated those differences by videotaping actors— two black men, two black women, two white men, and two white women— describing chest pain from identical scripts. They wore identical gowns, used identical gestures, and were taped from the same position. Researchers asked 720 primary care doctors at meetings of the American College of Physicians or the American Academy of Family Physicians to watch a tape and recommend care. The doctors thought the study focused on clinical decision making. Which video a particular doctor watched was determined by the roll of a four- sided die. Answer the following seven questions for the described experiment.
1. What question is the experiment trying to answer?
2. What are the experimental conditions (treatments) for this experiment?
3. What is the response variable?
4. What are the experimental units, and how were they selected?
5. Does the design incorporate random assignment of experimental units to the different experimental conditions? If not, are there potentially confounding variables that would make it difficult to draw conclusions based on data from the experiment?
6. Does the experiment incorporate a control group and or a placebo group? If not, would the experiment be improved by including them?
7. Does the experiment involve blinding? If not, would the experiment be improved by making it single- or double-blind?