1. The risk of acquiring disease is measured by the
a. Incidence rate
b. Incidence rate times the average duration of the disease
c. Incidence rate divided by the prevalence rate
d. Prevalence rate
e. Prevalence rate times the average duration of the disease
2. The strength of an association between a factor and a disease is best measure by .
a. Incubation rate
b. Incidence of the disease in the total population
c. Prevalence of the factor
d. Attributable risk
e. Relative risk
3. Case fatality rate for a given disease refers to
a. The crude mortality rate per 100,000 population
b. Cause-specific mortality rate due to the disease
c. A fatal outcome of any disease
d. The percentage of deaths among cases of the disease
e. The proportion of deaths due to the disease among all deaths from all causes
4. An investigator is interested in etiology of neonatal jaundice. To study this condition, he selected 100 children who were diagnosed with this condition and 100 children born in the same period and in the same hospital who did not have a diagnosis of neonatal jaundice. He then reviewed the obstetrical and delivery records of their mothers to determine various prenatal and perinatal exposures. This is an example of a(n):
a. Cross-sectional study
b. Case-control study
c. Cohort study
d. Clinical trial
e. Experiment
5. Which of the following statements describes the major advantages of a randomized clinical trial?
a. It avoids observer bias
b. It lends itself to ethical justification
c. It yields results replicable in other patients
d. It rules out self-selection of participants to the different treatment groups
d. It enrolls representative patients
6. A survey conducted in England revealed that of 224 families in which there had been a known case of poliomyelitis, 56 maintained parakeets as a family pet. In another British survey, 30 out of 99 poliomyelitis patients questioned kept parakeets. The inference that there is some relationship between the presence of a parakeet in a household and the occurrence of poliomyelitis among household members is
a. Correct b.
Incorrect because of failure to distinguish between incidence and prevalence
c. Incorrect because a proportionate ratio is used when a rate is required to support the inference
d. Incorrect because a failure to recognize a possible cohort phenomenon
e. Incorrect because there is no control or comparison group.
7. An investigator determines the correlation coefficient between triglyceride levels and degree of atherosclerosis in sampled blood vessels to be +1.67. On the basis of this you would conclude that:
a. Triglyceride level is a good predictor of atherosclerosis
b. Triglyceride level is not a good predictor of atherosclerosis
c. High triglyceride levels cause atherosclerosis
d. Atherosclerosis cause high triglyceride levels
e. The investigator has incorrectly determined the correlation coefficient
8. A screening test of known sensitivity and specificity is applied to two populations. The prevalence of the disease being screened for is 10% in population A and is 1% in population B. Which of the following is true?
a. The percent of all negative tests that have false-negative results is lower in population A than in population B.
b. Specificity is lower in population A than in population B.
c. Reliability is higher in population A than in population B.
d. The percent of all positive tests that have false-positive results is lower in population A than in population B.
e. Specificity is higher in population A than in population B.
9. Serum cholesterol levels are obtained for four healthy men. The probability that all will fall below the 10th percentile of the distribution of cholesterol for healthy males is:
a. 0.4
b. 1 รขยย (0.1)4
c. (0.1)4
d. (0.9)4
e. Cannot be determined from these data
10. In a diabetes screening program, the screening level for a positive blood sugar level in test 1 is set at 160 mg/dl, and in test 2 at 130 mg/dl. The sensitivity is:
a. Greater in test 1
b. Greater in test 2
c. Equal in test 1 and 2
d. Dependent on the size of the population being evaluated
