Exam 8: Experimental Study Designs

To test the efficacy of vitamin C in preventing colds, army recruits are randomly assigned to one of two groups: one in which 500 mg of vitamin C is administered daily, and one in which 500 mg of a placebo is administered daily. Both groups are followed to determine the number and severity of subsequent colds. Which of the following study designs most appropriately characterizes this situation?

The purpose of randomization is to reduce error that results from:

A prophylactic trial is designed to:

You would like to assess the effectiveness and efficiency of delivering health services through your clinic. After selecting a 10% sample of all patient visits during the past six months, you are able to characterize the patient population who used your clinic in terms of age, race, sex, method of referral, diagnostic category, therapy provided, method of payment, daily patient load, and clinic staff work schedules. Which of the following study designs most appropriately characterizes this situation?

To test the efficacy of a health education program in reducing the risk of foodborne and waterborne diseases, the residents of two Peruvian villages were given an intensive health education program. At the end of two years, the incidence rates of important waterborne and foodborne diseases in these villages were compared with those in two similar control villages without any education program. Which of the following study designs most appropriately characterizes this situation?

The entire population of a given community is examined, and all who are judged to be free from bowel cancer are questioned extensively about their diets. These people then are followed for several years to see whether their eating habits will predict their risk of developing bowel cancer. Which of the following study designs most appropriately characterizes this situation?

You are interested in finding out whether middle-aged men who have premature ventricular contractions (PVCs) are at greater risk of developing a myocardial infarction (heart attack) than men whose heartbeats are regular. Electrocardiogram (ECG) examinations are performed on all male office employees 35 years of age or older who work for oil companies in Houston. The ECG tracings are classified as irregular or regular. Five years later, myocardial infarction rates are compared between those with and those without baseline ECG irregularities. Which of the following study designs most appropriately characterizes this situation?

The Stanford Five-City Project, a major community trial designed to lower the risk of cardiovascular diseases, used two types of surveys to measure treatment-control differences across risk factors. What were they?

The Women's Health Initiative demonstrated that the benefits of hormone replacement therapy for cardiovascular disease had been overestimated.

An example of a famous heart disease program was the one conducted in North Carolina.

Match the following terms with their definitions. Toxicity

Surrogate endpoints for a clinical trial of a drug to control hypertension may include:

Match the following terms with their definitions. Informed consent