Public Health - View Kamer

Welcome to your ECN 2023 - Public Health

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81. Which of the following statement is not an advantage of a cross-sectional study?

A. It is quick and requires only one interview of study participants

B. It is useful for planning, designing and siting hospitals, budgeting for medicines, and determining types of services, as it indicates disease caseloads and care priorities

C. It is quick and require only one interview of study participants

D. It is useful for planning, designing and siting hospitals, budgeting for medicines, and determining types of services, as it indicates disease caseloads and care priorities

E. It allows the development of associations thus generating hypotheses of subsequent studies

82. All of the following factors will lead to decrease in the prevalence of disease in a community except one which one?

A. Emigration of cases affected by the disease

B. Improvement in the cure rate of disease cases

C. Increasing mortality rates from the disease

D. Increased duration of illness

E. Shorter duration of illness

Questions 83 and 84 You want to establish the extent of health conditions or disease and be able to compare the health conditions of different groups at any given time.

83. What measurement do you need for this exercise?

A. The number of people who have the health condition or disease and the size of the population at risk

B. The relative risk of disease and number of people who have the health condition or disease

C. The relative risk of disease and the population at the risk of disease

D. The attributable risk of the disease and the number of people who have the health condition or disease

E. The population at the risk of the disease

84. Logically, what do you call this measure?

A. Cumulative incidence

B. The instantaneous prevalence rate

C. The incidence rate

D. Loto of prevalence over a given period

E. None of the above

85. Which of the following is not an advantage of case control study?

A. It is a method of choice for less common or rare conditions or illnesses

B. Cases chosen for a case control study are selective survivors

C. It is a quick and inexpensive to make

D. It tends to support but not prove the causal hypothesis by establishing associations

E. The number of subjects needs to test a hypothesis of association is small compared to a cross-sectional or cohort study

Questions 86 to 90 The table above was obtained from a 1-year cohort study of 2000 men aged 40 to 49 to test the association between stroke and stress.

Stroke status	Stressed	Non-stressed	Total
Developed stroke	300	100	400
Did not develop a stroke	700	900	1600
Total	1000	1000	2000

86. What are the two variables controlled in this study?

A. Sex and stroke status

B. Sex and stress

C. Age and sex

D. Stress and stroke condition

E. Age and stroke status

87. What is the incidence of stroke among the stressed group?

A. 30%

B. 75%

C. 15%

D. 20%

E. None of the above

88. What is the incidence of stroke in the non-stressed group?

A. 5%

B. 10%

C. 25%

D. 30%

E. None of the above

89. What is the relative risk of stroke in stressed versus non-stressed people?

A. 2

B. 3

C. 4

D. 5

E. 6

90. What is attributable risk of stroke in stressed people compared to non-stressed?

A. 5

B. 10

C. 20

D. 30

E. None of the above

91. Evaluating a newly developed procedure against a standard procedure

A. The validity

B. Reliability

C. Both of them

D. Plausibility

E. None of the above

92. Comparisons of responses to a new questionnaire obtained one month apart

A. The validity

B. Reliability

C. Both above

D. The precision

E. None of the above

93. Expressed in terms of sensitivity and specificity

A. The validity

B. Reliability

C. Both above

D. None of the above

E. Predictive value

94. Which of the following is the most concerning common type of bias in cohort studies?

A. The lost sight

B. Random classification error

C. All of the above answers

D. Confusion bias

E. No answer above

95. Which of the following statements is not true of a P-value?

A. The p-value is a statement of conditional probability representing the probability that the result observed in the data of a study is due to chance given that the null hypothesis is true?

B. If the p-value is conventionally low less than 0.05 the null hypothesis of no associations is rejected and chance considered an unlikely explanation of the results

C. The magnitude of the difference between study groups can affect the size of the p-value

D. The sample size of the study population can affect the size of the p-value

E. None of the above

96. Restriction is a technique to control for confounding factors in the design phase of a study. Which of the following statements is not true about restriction?

A. Use of the restriction may substantially reduce the number of subjects eligible to participate in the study

B. Use involves residual confounding potential if criteria are not narrow enough

C. The restriction does not establish the association between exposure and disease for different of exposure factors

D. Restriction improves validity by providing an estimate that is not skewed by restriction factors

E. None of the above

97. Which of the following Bradford Hill criteria for disease causation is the least important?

A. The biological guardian

B. The strength of association

C. The specificity

D. The temporal relationship

E. The stability of the association

98. In the study of the cause of a disease, the essential difference between, the experimental study and the study of observation is that in an experimental investigation:

A. The study is prospective

B. The study is retrospective

C. Study and control groups are of equal size

D. Study and control groups are selected based on history of exposure on the suspected causative factor

E. Investigators determine who is and who is not exposed to the suspected causative factor

99. You are preparing a report to present to the public health board on the decline in gonorrhea rates in the area for both men and women over the past 10 years. Which graph would best illustrate the data?

A. Bar chart

B. Histogram

C. Camembert

D. Frequency polygon

E. Line diagram

100. Which of the following statements is a disadvantage of a crossover trial?

A. Subjects who respond to the treatment being tested are removed from it and given a placebo or an alternative treatment

B. The washout period with some drugs can be quite a long during which patients are given a placebo

C. It cannot be used if the has permanent effects

D. All of the above answers

E. None of the above