A hypothetical observational breast cancer study enrolled 10,000 women age 50 and older during 1990 and followed each woman for 10 years. All women received a free medical exam, including a mammogram, at baseline and each year thereafter. All deaths were full investigated and there was no loss to follow-up. At the baseline examination, 80 women were diagnosed with having early breast cancer. Twenty of these women died during the 10 year follow-up. By the end of follow-up, 240 other women had developed breast cancer, including 30 who died from their disease. Two hundred other women (who did not develop breast cancer) died from other causes.
a. What was the prevalence of diagnosed early breast cancer in the study population at baseline?
b. What was the 10-year case-fatality ârateâ in women with early breast cancer at baseline?
c. What was the cumulative incidence of breast cancer during the 10 year follow-up?
d. What was the incidence rate (incidence density) of breast cancer in the study population during the 10 year follow-up?
e. What was the breast cancer mortality rate in the study population during the 10 years?
f. What was the all-cause mortality rate in the study population during the 10 years?
g. What was the proportionate mortality for breast cancer?
h. What was the prevalence of (diagnosed) breast cancer in 2000?
A hypothetical observational breast cancer study enrolled 10,000 women age 50 and older during 1990 and followed each woman for 10 years. All women received a free medical exam, including a mammogram, at baseline and each year thereafter. All deaths were full investigated and there was no loss to follow-up. At the baseline examination, 80 women were diagnosed with having early breast cancer. Twenty of these women died during the 10 year follow-up. By the end of follow-up, 240 other women had developed breast cancer, including 30 who died from their disease. Two hundred other women (who did not develop breast cancer) died from other causes.
a. What was the prevalence of diagnosed early breast cancer in the study population at baseline?
b. What was the 10-year case-fatality ârateâ in women with early breast cancer at baseline?
c. What was the cumulative incidence of breast cancer during the 10 year follow-up?
d. What was the incidence rate (incidence density) of breast cancer in the study population during the 10 year follow-up?
e. What was the breast cancer mortality rate in the study population during the 10 years?
f. What was the all-cause mortality rate in the study population during the 10 years?
g. What was the proportionate mortality for breast cancer?
h. What was the prevalence of (diagnosed) breast cancer in 2000?
Related textbook solutions
Related questions
This includes showing all calculations and explaining why you selected a specific answer for each multiple choice question (i.e. donât just circle the correct answer). I am looking to see how you got the answer, not just that you have the correct answer.
Below is data from the United States Cancer Statistics about the number of news cases of lung cancer in males in the U.S. for 2011 for ages 30 and older.
Table 1: U.S. Population Size and Incidence Cases of Lung Cancer in Males for 2011
| Age (Years) | U.S. Male Population | White Population | White Incidence Cases | Black Population | Black Incidence Cases |
| 30-34 | 10,181,564 | 7,950,924 | 88 | 1,383,650 | 22 |
| 35-39 | 9,666,162 | 7,557,263 | 212 | 1,271,897 | 23 |
| 40-44 | 10,363,126 | 8,259,215 | 643 | 1,324,847 | 132 |
| 45-49 | 10,856,131 | 8,766,225 | 2,032 | 1,373,346 | 444 |
| 50-54 | 10,976,172 | 9,004,383 | 5,128 | 1,329,551 | 1,148 |
| 55-59 | 9,733,849 | 8,101,629 | 8,607 | 1,091,030 | 1,687 |
| 60-64 | 8,466,308 | 7,183,960 | 12,340 | 845,362 | 2,067 |
| 65-69 | 6,014,777 | 5,178,255 | 15,792 | 539,796 | 2,077 |
| 70-74 | 4,360,942 | 3,769,569 | 16,011 | 376,129 | 1,864 |
| 75-79 | 3,204,196 | 2,807,216 | 14,319 | 255,221 | 1,426 |
| 80-84 | 2,319,839 | 2,078,071 | 11,284 | 154,155 | 883 |
| 85+ | 1,873,942 | 1,688,433 | 7,616 | 117,267 | 545 |
| Total | 88,017,008 | 72,345,143 | 94,072 | 10,062,251 | 12,318 |
3. What is the age-specific incidence rate for lung cancer in white men age 75-79 for 2011?(1 pt)
0.005 per 1000
1.3 per 1000
1.2 per 1000
5.1 per 1000
5.6 per 1000
F. Cannot be calculated from the given information
4. What is the age-specific incidence rate for lung cancer in black men age 75-79 for 2011? (1 pt)
0.005 per 1000
1.3 per 1000
1.2 per 1000
5.1 per 1000
5.6 per 1000
F. Cannot be calculated from the given information
Questions 5 through 7 are based on the information below:
Using the information in Table 1, researchers calculated the crude incidence rates and age-adjusted incidence rates (via the direct method) for both groups.
Table 2: Crude incidence rates and age-adjusted incidence rates for white and black males
| White Males | Black Males | ||
| Crude Incidence Rate | Age-adjusted Incidence Rate | Crude Incidence Rate | Age-adjusted Incidence Rate |
| 1.3 per 1000 | 1.2 per 1000 | 1.2 per 1000 | 1.5 per 1000 |
5. True or False, there is likely a difference in the age composition between the white and black males. Explain your answer
6. Based on the information in Table 2, it was reported that there was an increased risk of lung cancer in black males in 2011. (1 pt)
The conclusion is:
Correct, the age-adjusted rate is higher in black males compared to white males
Correct, because both the crude and age-adjusted rates are higher in black males compared to white males
Incorrect, because the incidence rate for white males is actually higher than the incidence rate for black males
7. What type of age-adjusted rate was calculated in table 2? How does it differ from the age-adjusted rate in question 5 in the in-class exercise for age-adjustments? Hint: See slide title: Adjustments for Other Measures of Disease Frequency in the lecture title Adjusted Rates (1 pt)
Question 8 is based on the information given below:
Cause-specific mortality rates for men in 2010 in the U.S. from various types of cancers are shown in the table below:
Cause-Specific Mortality Rates
(per 100,000 Men)
Location of the Cancer
in the Body White Asian
Pancreas 13.2 5.7
Prostate 19.1 2.5
Lung 62.3 18.5
Skin 4.9 0.3
8. The inference that White men in the U.S. are at higher risk of death due to cancer of the pancreas, prostate, lung, and skin compared to Asian men in the U.S. is
A. correct
B. incorrect because of failure to determine cause-specific mortality rates
incorrect because proportionate mortality alone does not give an estimate of risk
D. incorrect because of failure to adjust for differences in the age composition of the two populations
E. incorrect because counts were used when cause-specific mortality rates were needed
9. In January 1996, a team of epidemiologists identified a sample of 4,500 men, 65-74 years of age, for a study of prostate cancer. Tests indicated that 315 of the men already had prostate cancer and, therefore, were not at risk. The rest of the men were followed prospectively for five years to determine the incidence rate of prostate cancer in the sample. By the end of the five years of follow-up 156 of the men had developed prostate cancer. What is the incidence rate of prostate cancer in this group?
10. An epidemiologic investigation that started on January 1, 2011, identified a population of 1,000 individuals. At the start of the study 4 were found to have the disease. During the year of study, 6 new cases were found; thus a total of 10 cases were identified. Among those 10 cases, 6 deaths occurred during the year. What was the prevalence of the disease during the 1-year study?
