Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 4

TABLE 2 Female Age-adjusted (to the 2000 U.S. Standard Population) Malignant First Primary Breast Cancer Incidence Rates in San Francisco and the Metropolitan Areas of Detroit and Atlanta for Whites and Blacks, 2006–2008

	White	Black	Other
Location	Rate per 100,000	Rate per 100,000	Rate per 100,000
San Francisco	139.3	122.1	103.2
Detroit (metropolitan)	120.8	120.4	59.2
Atlanta (metropolitan)	120.4	125.9	71.6
Three areas combined	127.6	122.8	95.4

Data from Surveillance Research Program, National Cancer Institute. SEER*Stat software Version 6.4.4.

Available at: http:///www.seer.cancer.gov/seerstat.Accessed January 10, 2012.

The crude rate ratio between whites and blacks is 1.34. The corresponding rate ratio based on the age-adjusted rates is 1.0What does this tell you about the age distribution among the geographic populations?

Step 1 of 3

Crude rate for malignant breast cancer-induced deaths can be calculated by dividing the number of persons who died from this cause by the total number of persons in the population. The crude rate is calculated for a geographic area over a specified time period. Age-specific death rate could be defined as the number of people belonging to a specified age group divided by the average population of this age group.