1/10
A new test to diagnose urinary tract infections (UTls) is being evaluated. The sensitivity of the test is 70% and the specificity is 90%. In the study there are 100 patients who actually have UTls and 200 who actually do not, as determined by the diagnostic gold standard. How many false positives are in this study?
- 20
- 30
- 70
- 120
- 180
2/10
Women who have just delivered babies with neural tube defects are asked about their use of acetaminophen during the first three months of pregnancy. Women who delivered apparently healthy babies are also asked about their use of acetaminophen during the first three months of pregnancy. Which of the following measures of association are the investigators most likely to report?
- Relative risk
- Median survival
- Exposure odds ratio
- Relative rate
- Prevalence odds ratio
3/10
A large prospective study evaluates the relationship between alcohol consumption and breast cancer. A total of 4000 middle-aged women are enrolled in the study through a random selection of residential addresses. Daily alcohol consumption and breast cancer incidence are assessed through the use of periodic questionnaires. Five-year follow-up shows that alcohol consumers are somewhat more likely to develop breast cancer (relative risk = 1.32,95% confidence interval = 0.90-1.85). The investigators also report that 800 subjects were lost to follow-up by the end of the study, the majority of whom were moderate to heavy alcohol consumers. According to this information, which of the following biases is most likely to be present and may have affected the results?
- Lead-time bias
- Observer bias
- Random misclassification bias
- Recall bias
- Selection bias
4/10
4. A new serologic test has been developed for the detection of active pulmonary tuberculosis and is compared to the gold standard of sputum mycobacterial culture. A total of 1000 subjects are randomly selected = testing from a population with a high prevalence of tuberculosis. Results of the study are given below.
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Which of the following is the positive predictive value of the test under study?
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Which of the following is the positive predictive value of the test under study?
- 130/180
- 130/190
- 180/1000
- 760/810
- 760/820
5/10
A 65-year old man with a history of congestive heart failure is hospitalized with chest pain and hypotension requiring admission to the cardiac care unit. An intra-arterial line is placed for direct blood pressure monitoring. Consecutive readings of his intra-arterial blood pressure are 75, 110, 80, 90, 75, and 110 mm Hg. Which of the following represents the median of these blood pressure readings?
- 80mmHg
- 85rnrnHg
- 90mmHg
- 100mmHg
- 110mmHg
6/10
A 73-year-old man comes to the office for follow -up. He was diagnosed with chronic Iymphocytic leukemia (ell) 3 years ago when routine laboratory testing revealed a markedly elevated leukocyte count. He ~eels well. On examination he has stable lymphadenopathy. He has been reading about management options should his CLL progress and inquires about an experimental drug that selectively binds malignant lymphocytes. The drug has been shown to significantly prolong survival in patients with stage 3 and ~ ell, without curing the malignancy. If this new drug were widely used, what changes would be expected In the number of incident and prevalent cases of ell?
- The number of incident cases wil ldecrease, the number of prevalent cases will decrease
- The number of incident cases will increase, the number of prevalent cases will not change
- The number of incident cases will decrease, the number of prevalent cases will increase
- The number of incident cases will not change, the number of prevalent cases will increase
- The number of incident cases will not change, the number of prevalent cases will not change
7/10
A new test to diagnose urinary tract infections in women is being evaluated. The comparison gold standard is positive urine dipstick plus urine culture. Results of the study are given below.
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What is the new test's specificity?
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What is the new test's specificity?
- 10%
- 30%
- 50%
- 70%
- 90%
8/10
A researcher studying physician behavior is interested in how often primary care physicians take the sexual histories of patients during clinic visits. As part of the study, patients who attend a primary care .clinic are
asked to fill out a questionnaire immediately following a visit with their physician. Once the physicians become aware that their own behavior is being studied, which of the following is most likely to be a potential problem?
asked to fill out a questionnaire immediately following a visit with their physician. Once the physicians become aware that their own behavior is being studied, which of the following is most likely to be a potential problem?
- Berkson's bias
- Hawthorne effect
- Lead-time bias
- Pygmalion effect
- Recall bias
9/10
A rare metabolic disease has severe consequences if left untreated. If detected early after birth, the disease can be treated effectively and all the severe sequelae can be prevented. It is most important for a test to be used in all newborns to have a high:
- Cutoff value
- Number of true negatives
- Positive predictive value
- Sensitivity
- Specificity
10/10
The figure below shows the incidence and mortality for the three most common cancers affecting women living in the United States during 2011. The x-axis lists the specific cancers, and the y-axis shows the number of patients affected.
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Which of the following lists of cancers best corresponds to cancers 1, 2, and 3 respectively?
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Which of the following lists of cancers best corresponds to cancers 1, 2, and 3 respectively?
- Breast,lung,colon
- Lung,breast,colon
- Breast,ovary,lung
- Lung,breast,cervix
- Breast,colon,lung
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