A Case-Control Study
REVIEW QUESTIONS FOR CHAPTER 10 1. A case-control study is characterized by all of the following except:
a. It is relatively inexpensive compared with most other epidemiologic study designs
b. Patients with the disease (cases) are compared with persons without the disease (controls) c. Incidence rates may be computed directly d. Assessment of past exposure may be biased e. Definition of cases may be difficult
2. Residents of three villages with three different types of water supply were asked to participate in a survey to identify cholera carriers. Because several cholera deaths had occurred recently, virtually everyone present at the time underwent examination. The proportion of residents in each village …show more content…
who were carriers was computed and compared. What is the proper classification for this study?
a. Cross-sectional study b. Case-control study c. Concurrent cohort study d. Nonconcurrent cohort study e. Experimental study
3. Which of the following is a case-control study? a. Study of past mortality or morbidity trends to permit estimates of the occurrence of disease in the future
b.
Analysis of previous research in different places and under different circumstances to permit the establishment of hypotheses based on cumulative knowledge of all known factors
c. Obtaining histories and other information from a group of known cases and from a comparison group to determine the relative frequency of a characteristic or exposure under study
d. Study of the incidence of cancer in men who have quit smoking e. Both a and c
4. In a study begun in 1965, a group of 3,000 adults in Baltimore were asked about alcohol consumption. The occurrence of cases of cancer between 1981 and 1995 was studied in this group. This is an example of:
a. A cross-sectional study b. A concurrent cohort study c. A retrospective cohort study d. A clinical trial e. A case-control study 5. In a small pilot study, 12 women with endometrial cancer (cancer of the uterus) and 12 women with no apparent disease were contacted and asked whether they had ever used estrogen. Each woman with cancer was matched by age, race, weight, and parity to a woman without disease. What kind of study design is this?
a. Concurrent cohort b. Retrospective cohort c. …show more content…
Case-control d. Cross-sectional e. Experimental 6. The physical examination records of the entire incoming freshman class of 1935 at the University of Minnesota were examined in 1977 to see if their recorded height and weight at the time of admission to the university was related to the development of coronary heart disease by 1986. This is an example of:
a. A cross-sectional study b. A case-control study c. A concurrent cohort study d. A retrospective cohort study e. An experimental study 7. In a case-control study, which of the following is true? a. The proportion of cases with the exposure is compared with the proportion of controls with the exposure
b. Disease rates are compared for people with the factor of interest and for people without the factor of interest c. The investigator may choose to have multiple comparison groups d. Recall bias is a potential problem e. a, c, and d
8. In which one of the following types of study designs does a subject serve as his own control?
a. Prospective cohort study b. Retrospective cohort study c. Case-cohort study d. Case-crossover study e. Case-control study
REVIEW QUESTIONS FOR CHAPTER 11
1. Of 2,872 persons who had received radiation treatment in childhood because of an enlarged thymus, cancer of the thyroid developed in 24 and a benign thyroid tumor developed in 52. A comparison group consisted of 5,055 children who had received no such treatment (brothers and sisters of the children who had received radiation treatment). During the follow-up period, none of the comparison group developed thyroid cancer, but benign thyroid tumors developed in 6. Calculate the relative risk for benign thyroid tumors: 15.2 2.
In a study of a disease in which all cases that developed were ascertained, if the relative risk for the association between a factor and the disease is equal to or less than 1.0, then:
a. There is no association between the factor and the disease b. The factor protects against development of the disease c. Either matching or randomization has been unsuccessful
d. The comparison group used was unsuitable, and a valid comparison is not possible
e. There is either no association or a negative association between the factor and the disease
Questions 3 and 4 are based on the information given in the following table.
In a small pilot study, 12 women with uterine cancer and 12 with no apparent disease were contacted and asked whether they had ever used estrogen. Each woman with cancer was matched by age, race, weight, and parity to a woman without disease. The results are shown below:
3. What is the estimated relative risk of cancer when analyzing this study as a matched-pairs study? a.
0.25 b. 0.33 c. 1.00 d.3.00 e. 4.20 4. Unmatch the pairs. What is the estimated relative risk of cancer when analyzing this study as an unmatched study design?
a. 0.70 b. 1.43 c. 2.80 d. 3.00 e. 4.00
Questions 5 through 7 are based on the following information.
Talbot and colleagues carried out a study of sudden unexpected death in women. Data on smoking history are shown in the following table.
5. Calculate the matched-pairs odds ratio for these data. 4.5
6. Using data from the table, unmatch the pairs and calculate an unmatched odds ratio. 6.3
7. What are the odds that the controls smoke 1+ pack/day? 1 :7 (.0143)
Questions 8 and 9 are based on the information given in the table at the bottom of this page.
8. The relative risk for developing ASHD subsequent to entering this study in men as compared to women is:
a. Approximately equal in all age groups b. Highest in the oldest age group
c. Lowest in the youngest and oldest age groups, and highest at ages 35–44 and 45–54 years
d. Highest in the youngest and oldest age groups, and lowest at ages 35–44 and 45–54 years e. Lowest in the oldest age group
9. The most likely explanation for the differences in rates of ASHD between the initial examination and the yearly follow-up examinations in men is:
a. The prevalence and incidence of ASHD increase with age in men b. Case-fatality rates of ASHD are higher at younger ages in men c. A classic cohort effect explains these results
d. The case-fatality rate in ASHD is highest in the first 24 hours following a heart attack
e. The initial examination measures the prevalence of ASHD, whereas the subsequent examinations primarily measure the incidence of ASHD
REVIEW QUESTIONS FOR CHAPTER 12
1. Several studies have found that approximately 85% of cases of lung cancer are due to cigarette smoking. This measure is an example of:
a. An incidence rate b. An attributable risk c. A relative risk d. A prevalence risk e. A proportionate mortality ratio
Questions 2 and 3 refer to the following information:
The results of a 10-year cohort study of smoking and coronary heart disease (CHD) are shown below:
2. The incidence of CHD in smokers that can be attributed to smoking is: 27.5/1,000 3. The proportion of the total incidence of CHD in smokers that is attributable to smoking is: 84.6%
Questions 4 and 5 are based on the following information:
In a cohort study of smoking and lung cancer, the incidence of lung cancer among smokers was found to be 9/1,000 and the incidence among nonsmokers was 1/1,000. From another source we know that 45% of the total population were smokers.
4. The incidence of lung cancer attributable to smoking in the total population is: 3.6/1,000
5. The proportion of the risk in the total population that is attributable to smoking is: 78.3%
a. It is relatively inexpensive compared with most other epidemiologic study designs
b. Patients with the disease (cases) are compared with persons without the disease (controls) c. Incidence rates may be computed directly d. Assessment of past exposure may be biased e. Definition of cases may be difficult
2. Residents of three villages with three different types of water supply were asked to participate in a survey to identify cholera carriers. Because several cholera deaths had occurred recently, virtually everyone present at the time underwent examination. The proportion of residents in each village …show more content…
who were carriers was computed and compared. What is the proper classification for this study?
a. Cross-sectional study b. Case-control study c. Concurrent cohort study d. Nonconcurrent cohort study e. Experimental study
3. Which of the following is a case-control study? a. Study of past mortality or morbidity trends to permit estimates of the occurrence of disease in the future
b.
Analysis of previous research in different places and under different circumstances to permit the establishment of hypotheses based on cumulative knowledge of all known factors
c. Obtaining histories and other information from a group of known cases and from a comparison group to determine the relative frequency of a characteristic or exposure under study
d. Study of the incidence of cancer in men who have quit smoking e. Both a and c
4. In a study begun in 1965, a group of 3,000 adults in Baltimore were asked about alcohol consumption. The occurrence of cases of cancer between 1981 and 1995 was studied in this group. This is an example of:
a. A cross-sectional study b. A concurrent cohort study c. A retrospective cohort study d. A clinical trial e. A case-control study 5. In a small pilot study, 12 women with endometrial cancer (cancer of the uterus) and 12 women with no apparent disease were contacted and asked whether they had ever used estrogen. Each woman with cancer was matched by age, race, weight, and parity to a woman without disease. What kind of study design is this?
a. Concurrent cohort b. Retrospective cohort c. …show more content…
Case-control d. Cross-sectional e. Experimental 6. The physical examination records of the entire incoming freshman class of 1935 at the University of Minnesota were examined in 1977 to see if their recorded height and weight at the time of admission to the university was related to the development of coronary heart disease by 1986. This is an example of:
a. A cross-sectional study b. A case-control study c. A concurrent cohort study d. A retrospective cohort study e. An experimental study 7. In a case-control study, which of the following is true? a. The proportion of cases with the exposure is compared with the proportion of controls with the exposure
b. Disease rates are compared for people with the factor of interest and for people without the factor of interest c. The investigator may choose to have multiple comparison groups d. Recall bias is a potential problem e. a, c, and d
8. In which one of the following types of study designs does a subject serve as his own control?
a. Prospective cohort study b. Retrospective cohort study c. Case-cohort study d. Case-crossover study e. Case-control study
REVIEW QUESTIONS FOR CHAPTER 11
1. Of 2,872 persons who had received radiation treatment in childhood because of an enlarged thymus, cancer of the thyroid developed in 24 and a benign thyroid tumor developed in 52. A comparison group consisted of 5,055 children who had received no such treatment (brothers and sisters of the children who had received radiation treatment). During the follow-up period, none of the comparison group developed thyroid cancer, but benign thyroid tumors developed in 6. Calculate the relative risk for benign thyroid tumors: 15.2 2.
In a study of a disease in which all cases that developed were ascertained, if the relative risk for the association between a factor and the disease is equal to or less than 1.0, then:
a. There is no association between the factor and the disease b. The factor protects against development of the disease c. Either matching or randomization has been unsuccessful
d. The comparison group used was unsuitable, and a valid comparison is not possible
e. There is either no association or a negative association between the factor and the disease
Questions 3 and 4 are based on the information given in the following table.
In a small pilot study, 12 women with uterine cancer and 12 with no apparent disease were contacted and asked whether they had ever used estrogen. Each woman with cancer was matched by age, race, weight, and parity to a woman without disease. The results are shown below:
3. What is the estimated relative risk of cancer when analyzing this study as a matched-pairs study? a.
0.25 b. 0.33 c. 1.00 d.3.00 e. 4.20 4. Unmatch the pairs. What is the estimated relative risk of cancer when analyzing this study as an unmatched study design?
a. 0.70 b. 1.43 c. 2.80 d. 3.00 e. 4.00
Questions 5 through 7 are based on the following information.
Talbot and colleagues carried out a study of sudden unexpected death in women. Data on smoking history are shown in the following table.
5. Calculate the matched-pairs odds ratio for these data. 4.5
6. Using data from the table, unmatch the pairs and calculate an unmatched odds ratio. 6.3
7. What are the odds that the controls smoke 1+ pack/day? 1 :7 (.0143)
Questions 8 and 9 are based on the information given in the table at the bottom of this page.
8. The relative risk for developing ASHD subsequent to entering this study in men as compared to women is:
a. Approximately equal in all age groups b. Highest in the oldest age group
c. Lowest in the youngest and oldest age groups, and highest at ages 35–44 and 45–54 years
d. Highest in the youngest and oldest age groups, and lowest at ages 35–44 and 45–54 years e. Lowest in the oldest age group
9. The most likely explanation for the differences in rates of ASHD between the initial examination and the yearly follow-up examinations in men is:
a. The prevalence and incidence of ASHD increase with age in men b. Case-fatality rates of ASHD are higher at younger ages in men c. A classic cohort effect explains these results
d. The case-fatality rate in ASHD is highest in the first 24 hours following a heart attack
e. The initial examination measures the prevalence of ASHD, whereas the subsequent examinations primarily measure the incidence of ASHD
REVIEW QUESTIONS FOR CHAPTER 12
1. Several studies have found that approximately 85% of cases of lung cancer are due to cigarette smoking. This measure is an example of:
a. An incidence rate b. An attributable risk c. A relative risk d. A prevalence risk e. A proportionate mortality ratio
Questions 2 and 3 refer to the following information:
The results of a 10-year cohort study of smoking and coronary heart disease (CHD) are shown below:
2. The incidence of CHD in smokers that can be attributed to smoking is: 27.5/1,000 3. The proportion of the total incidence of CHD in smokers that is attributable to smoking is: 84.6%
Questions 4 and 5 are based on the following information:
In a cohort study of smoking and lung cancer, the incidence of lung cancer among smokers was found to be 9/1,000 and the incidence among nonsmokers was 1/1,000. From another source we know that 45% of the total population were smokers.
4. The incidence of lung cancer attributable to smoking in the total population is: 3.6/1,000
5. The proportion of the risk in the total population that is attributable to smoking is: 78.3%