Question

1. You want to study the relationship between fat intake (g/day) and the death rate in the Central Valley. Your friend, from PH 109, suggests that you conduct an ecological study first. You found the data and summarized it below. What is the association between fat intake (g/day) and death rate? Explain the ecological fallacy. Please show your scatter plot. (3 points)

County	Fat Intake (g/day)	Age-adjusted death rate (per 100,000 population)
Fresno	140	2.1
Kings	120	1.9
Tulare	119	0.8
Madera	130	0.9
Stanislaus	100	1.0
Merced	121	1.2
Kern	98	1.3
San Joaquin	95	1.1

2. In order to study the relationship between alcohol intake (high or low) and liver cancer, 2,345 persons with incident liver cancer were identified through cancer registries. 3,246 people without liver cancer, selected from the DMV registries were also included in this study. Alcohol intake data was collected through mailed questionnaires. 825 of the people with liver cancer and 855 of those without liver cancer reported high alcohol intake, while the others reported low alcohol intake.

1. Calculate and interpret the appropriate measure of association for the alcohol intake level and liver cancer association. Fill in the table below. (3 points)

Alcohol intake	Liver cancer	No liver cancer	Total
High
Low
Total

2) A matched case-control study was carried out to assess the possible association between high-fat diet and colon cancer. The data are presented below.

	CONTROLS
CASES	Exposed	Not Exposed
Exposed	30	80
Not Exposed	50	240

Total = 400 matched pairs

1. Calculate the appropriate measure of association taking matching into account. (2 points)

b.   Construct an unmatched 2 х 2 table. Calculate the OR without taking the matching into account. (2 points)

	Cases	Controls
Exposed
Non-Exposed
Total

Answer 1