Determine disease status first, and then collect exposure history information.

Questions 2 and 3 are based on the information below:

Incidence of Coronary Heart Disease (CHD) in Men, According to Initial Cholesterol Level, Followed Over a 10 Year Period (1985-1995) CHD incidence (per 1,000 men) Cholesterol level in 1985 (mg/dL) 300 40 80 140

2. The data in the above table have been obtained from a: (2 pts) A. Case-control study B. Cohort study C. Cross sectional study D. Ecological study E. Cannot be determined from these data

3. The relative risk (RR) of coronary heart disease for men in the highest cholesterol group compared to the lowest group is: (3 pts) A. 140 – 40 = 100 per 1,000 B. 40/140 = 0.29 C. 140/40 = 3.50 D. Cannot be determined from these data

4. If there were no association between an exposure and disease, one would expect the following: (2 pts) A. Relative risk = 1.0 ; Proportion attributable risk = 1.0 B. Relative risk < 1.0 ; Proportion attributable risk < 50% C. Relative risk > 1.1; Proportion attributable risk > 50% D. Relative risk = 1.0; Proportion attributable risk = 0%

5. When a new treatment is developed which prevents death but does not result in the recovery from a non-infectious disease, which of the following will occur? (3 pts) A. Incidence of the disease will decrease B. Prevalence of the disease will increase C. Prevalence of the disease will decrease D. Both the incidence and the prevalence of the disease will increase

6. From January 1988 until March 1990 a research group in New Zealand followed 2,607 infants from the day they were born. Mothers were asked, “What position does your baby usually sleep in?” Mothers of 830 infants reported that their baby slept prone (on its stomach). Among this group, there were 9 infant deaths from Sudden Infant Death Syndrome (SIDS). The remaining 1,777 mothers reported that their baby slept on its side or its back. Among this group, there were 6 deaths from SIDS.

a. What type of study is this? (2 pts)

b. Construct a 2 x 2 table for these data. (4 pts)

c. Calculate the appropriate measure of association and state in words what this number means (one sentence). Show calculations. (6 pts)

7. Are the following examples of incidence or prevalence? Please put your answers under each example. (2 pts each) a. “Rates [of pancreatic cancer] increase rapidly with age as seen in data from the United States, where the rates for patients ages 70–74 are about 57 per 100,000 per year compared to rates of 9.8 per 100,000 in patients age 50–54.” (Lowenfels and Maisonneuve, 2006, p. 200.)

b. “Nearly 5 million asthma sufferers are under age 18. It is the most common chronic childhood disease, affecting more than one child in 20.” (Morbidity and Mortality Weekly Report, NCHS, U.S. CDC, 2003.)

c. Over the past five years, 350 cases of over-worked graduate students have been diagnosed at Drexel University.

8. Match the appropriate sequence of data collection (1-3) with each study design listed below (i.e., for each study design, fill in 1, 2 or 3). (2 pts each)

1. Determine exposure status first, and then collect disease status information. 2. Determine disease status first, and then collect exposure history information. 3. Determine disease status and exposure status at the same point in time.