Question

PERIPHERAL ARTERY DISEASE

Cholesterol-lowering drugs may also be effective at relieving leg pain.

• THE QUESTION Do the cholesterol-lowering drugs called statins also relieve the pain of peripheral artery disease?

• PAST STUDIES have shown that people with peripheral artery disease (PAD) often experience cramps and pain in their legs and buttocks during activity due to clogged leg arteries (claudication). Some researchers believe that lowering cholesterol levels may relieve PAD symptoms.

• THIS STUDY funded by Pfizer, the manufacturer of Lipitor, examined the effects of atorvastatin (Lipitor) in 354 PAD patients who were randomly assigned to one of two dosages of the drug (10 or 80 milligrams daily) or a placebo. Lipitor is one of several different drugs called statins. After a year, those in the low-dose Lipitor group reported to the researchers that were able to walk without leg pain on a treadmill for as long as those in the placebo group. Those taking the higher dose, however, reported to the researchers that they could walk substantially longer without pain than people in the other two groups. Participants in both Lipitor groups also felt they improved in their physical activities at work and at home. In addition, 1.3 percent of the Lipitor patients experienced worsening of symptoms or had surgery to redirect blood flow, compared with 7.9 percent of those receiving placebo.

a. What is the sample in this study?
b. What is the likely population?
c. Is this a correlational study or an experiment? Explain
d. What is the independent variable(s)?
e. What is the dependent variable (s)?
f. What is one possible confounding variable to this study (as it is stated)? g. State the null hypothesis in this study.

Answer 1

a.Sample in this study - sample is basically the participants in 5he study. So, 354 people participated in the study. Therefore the sample is 354.

b. Likely population - population in a research refers to the people to which the broad generalisations made will be applied. Here, the broad generalisations will be applied to the PAD patients. Therefore, likkely population - PAD patients

c. This is an experiment as an experiment is used to find the cause and effect relationship. Here, the administration of the drug 'Lipitor' will cause some effects on the patients whereas correlational study looks for association among naturally occurring variables. Example of a correlational study is - 'Drinking is associated with poor grades '

d.Independent Variable - Administration of the drug Lipitor, dosage of the drug and placebo.

e.Dependent Variable - Effect of the drug Lipitor on the patients

f.Confounding variable - It is an extraneous variable that was not accounted for. It damages the validity of the experiment and produces useless results. One possible Confounding variable is age. Another is various diseases other than PAD and cholesterol.

g.Null hypothesis - Cholesterol lowering drug lipitor does not relieve the pain of PAD.