CPH Questions

Question 1

The lengths of stay for six patients were 0, 0, 1, 2, 2, and 16 days. Which is (are) the best measure(s) to summarize these data?

Answer 1

E) Median and Range

Question 2

An epidemiologist attempts to predict the weight of an elderly person from demispan. She randomly chooses 70 elderly subjects in a particular geographic area and records their weight and demispan measurements in the form of (x i , y i ) for i = 1…70. Given that the value of the Pearson correlation coefficient is zero, what can be deduced?

1) There is no relation between weight and demispan
B) There is an almost perfect relationship between weight and demispan
C) There could be some nonlinear relationship between weight and demispan
D) There is a strong negative relationship between weight and demispan
E) All pairs of values of weight and demispan are practically identical

Answer 2

C) There could be some nonlinear relationship between weight and demispan

Question 3

Which of the following statistical tests is NOT considered a nonparametric test?

A) Kruskal-Wallis Test
B) Wilcoxon’s rank-sum test
C) Tukey’s test
D) Mann-Whitney test

Answer 3

C) Tukey’s test

Question 4

A researcher is designing a new questionnaire to examine patient stress levels on a scale of 0 to 5. What type of outcome variable is being collected?

A) Ratio
B) Nominal
C) Interval
D) Ordinal
E) Binary

Answer 4

D) Ordinal

Question 5

In simple linear regression, what is a method of determining the slope and intercept of the best-fitting line?

A) Least squares
B) R-square
C) Minimum error
D) Least Error
E) Regression

Answer 5

A) Least squares

Question 6

The sensitivity of a particular screening test for a disease is 95%, and the specificity is 90%. Which of the following statements is most correct?

(A) Of 100 people sampled from a population with the disease, the test will correctly detect 95 individuals as positive for the disease
(B) Of 100 people sampled from a population with the disease, the test will correctly detect 90 individuals
(C) If a person tests positive, the probability of having the disease is 0.95
(D) If a person has the disease, there is a 5% chance that the test will be negative
(E) If a person does not have the disease, there is a 5% chance that the test will be positive

Answer 6

A) Of 100 people samples from a population with the disease, the test will correctly detect 95 individuals as positive for the disease.

Sensitivity is the proportion of truly diseased people in the screened population who are identified as diseased by the screening test. It is a measure of the probability of correctly diagnosing a case or the probability that any given case will be identified by the test (e.g., true positives). Specificity is the proportion of truly non-diseased people who are so identified by the screening test. It is a measure of the probability of correctly identifying a nondiseased person with the screening test (e.g., true negatives).

Question 7

The Central Limit Theorem states that:

A) The sample mean is unbiased
B) The sample mean is approximately normal
C) The parent population of the sample distribution is normally distributed
D) The sample SD is approximately normal
E) Both statements A) and C) can be deduced from the Central Limit Theorem

Answer 7

B) The sample mean is approximately normal

The Central Limit Theorem states that if the sample size is large enough, the distribution of the
sample means can be approximated by a normal distribution, even if the original population is not
normally distributed. In other words, the distribution of the sample means approaches a normal distribution as the sample size increases

Question 8

Assume that a researcher has measured weight in a sample of 100 overweight adults before and after a diet and exercise program conducted at the local health department’s weekly Eat Health - Be Fit community program.

To determine whether the mean weight decreased six weeks after the exercise program compared to the initial baseline measures, the researcher should:

A) Compute the correlation coefficient, r, and determine the association between being overweight and the community program
B) Conduct a t-test for independent samples
C) Conduct a t-test for dependent samples
D) Conduct a chi-square test for association
E) Not estimate the decrease because there was no control group for the program

Answer 8

C) Conduct a t-test for dependent samples

A t-test is a hypothesis test to compare population means and proportions. In this case, the sample is
dependent because the tests are performed on the same individuals in the sample.

Question 9

Which of the following estimates of an odds ratio most strongly suggests a computational error?

1) 7.8
2) 1.2
3) -0.9
4) 20.9

Answer 9

3) -0.9

An odds ratio of -0.9 most strongly indicates a computational error because an odds ratio is calculated using probabilities, which cannot be negative.

An odds ratio is the probability that an event will occur divided by the probability that it will not occur. Since probabilities cannot be negative, a negative odds ratio would indicate computational error.

Question 10

Which measure of mortality would you calculate to determine the proportion of all deaths that is caused by heart disease?

A) Case Fatality Ratio
B) Randomized Clinical Trial
C) Crude Mortality Rate
D) Proportional Mortality Ratio

Answer 10

D) Proportional Mortality Ratio

the proportion of deaths in a particular population over a specified period of time attributable to a specific disease

Question 11

An incremental approach to program planning in public health is:

1) Uses multiple sources and methods to collect similar information
2) Provides an intensive, detailed description and analysis of a single project
3) Produces a plan where the specification of every step depends up on the results of previous steps
4) Results in plans that may be immediately necessary but may overlap or leave gaps

Answer 11

4) Results in plans that may be immediately necessary but may overlap or leave gaps

The incremental approach to program (a little bit more is added each time) planning may address an immediate need (ex: Closing bathhouses in the early days of HIV/AIDS epidemic) it may also leave gaps (ex: Did not identify the virus).

The incremental approach to program planning will address only part of the problem, may be the result of disjointed efforts and leave many factors unaccounted for.

Question 12

In a state with a state-directed pubic health organization, the State Commissioner of Health has notified health districts to close health department dental programs in response to a state legislature vote to defund and discontinue health department dental services.

The district health department has identified dental services as a leading community health need. To help assure continued access to services, the best first step is to:

1) Develop a list of possible venues and proposals to secure financial support, and present them to the Commissioner’s office

2) develop agreements with local providers or organizations for the provision of dental services

3) continue the dental program in-house at the local health department, since it was already financially sustainable and heavily utilized

4) ensure implementation of contracts and other agreements with community partners to provide community dental services

Answer 12

1) Develop a list of possible venues and proposals to secure financial support, and present them to the Commissioner’s office

Since the upper chain of state health command has ordered dental service closure, consultation with the Commissioner’s office will be needed to assure compliance with legislative directives and fidelity to state health department policy.

The likelihood of support from the state-level is greater if it is well-defined and sustainable options are presented.

Question 13

A researcher has implemented an intervention. The program activities include STD counseling for the members of a community-based organization. One outcome measure would be best addressed by which of the following questions?

1.) Did STD counseling result in changes in knowledge among the target population?
2.) When did the program activities take place?
3.) What are the barriers to implementation of program activities?
4.) What is the number of people who received counseling?

Answer 13

1.) Did STD counseling result in changes in knowledge among the target population?

Outcome evaluation measures the program effects on the target population.

Question 14

Which of the following is the most accurate exposure assessment in workers?
1.) Determination of the chemical in the air
2.) Biomonitoring of chemicals or metabolites in blood or urine
3.) Determination of the chemical on the skin
4.) Estimation of the exposure by taking an occupational history

Answer 14

2.) Biomonitoring of chemicals or metabolites in blood or urine

Biomonitoring gives the best estimate for individual exposure. This approach involves collecting bodily fluids or other biological samples and analyzing them for the presence of a contaminant, the metabolite of the contaminant, or a biological response.

Biomonitoring proves that absorption of a contaminant has occurred and accounts for absorption through all routes of exposure. Because individuals naturally vary in their ability to metabolize a compound, biomonitoring can indicate which individuals are most susceptible to deleterious health effects from an exposure.

Other approaches to estimating an individual’s exposure, such as measuring a contaminant’s presence in the air, determining a contaminant’s presence on the skin, or completing a job-exposure matrix will not yield information about uptake, metabolism, and individual susceptibilities.

Question 15

If a food contaminated with a virus, such as hepatitis A, is left out for 4 hours in a kitchen at a temperature of 85 degrees Fahrenheit, the virus count in the food:

1) increases exponentially
2) increases slowly
3) depends on the acidity of food
4) does not change

Answer 15

4) does not change

Viruses can only grow in living cells and will not multiply under these circumstances.

Viruses can only replicate themselves by infecting a host cell and therefore cannot reproduce on their own.

Question 16

Which of the following statements is not associated with the current paradigm of quality management?

1) Sanctioning individuals for mistakes is the most appropriate method for ensuring effective quality of care.
2) The appropriate locus for ensuring quality is at the system level
3) Process improvement is essential to ensuring quality of care
4) Employee satisfaction and patient satisfaction are closely linked

Answer 16

1) Sanctioning (punishing) individuals for mistakes is the most appropriate method for ensuring effective quality of care

This is the only correct response because the current quality management paradigm considers the primary source of errors, waste, and other indicators of poor quality to be poor system design and ineffective processes rather than individual incompetence or carelessness. Deming and others regard the sanctioning of individuals for poor quality to be misplaced and likely to aggravate the problem.

Focus on errors in the system - not the individual.

Question 17

Which term is used to characterize the movement addressing the social condition of unequal distribution of environmental hazards experienced by minority populations or groups with low income?

1) Environmental equity
2) Environmental justice
3) Environmental pollution
4) Environmental democracy

Answer 17

Churches and other nonprofit interest groups that launched the environmental fairness movement in the 1980s articulated their mission using the term “Environmental Justice.” The overarching premise is fairness in the distribution of the burden of pollution across all population groups regardless of race, ethnicity or socio-economic status.

The term “Environmental equity” is not the best answer because while it may be a component of environmental justice, it is more limited. Environmental justice encompasses equity, as well as equality and fairness.

The term “Environmental pollution” is only vaguely expressive of the message, but does not capture concern with how exposure to environmental pollution is distributed across a population.

The term “Environmental democracy” is completely wrong because it is not about majority rule. If it were a matter of majority rule, than minority health could be in serious jeopardy.

Environmental equity is an outcome of Environmental justice.

Question 18

If two events are mutually exclusive, to determine the probability that one or the other happened:

1) Double their probabilities
2) Add their conditional probabilities
3) Add their individual probabilities
4) Multiply their individual probabilities

Answer 18

3) Add their individual probabilities

mutually exclusive (disjoint): describes events which cannot occur at the same time, such as a screening test indicating that someone is both positive and negative for a condition

The special addition rule of probability holds that for two mutually exclusive events, the probability that one or the other of the events has occurred is equal to the sum of of the probabilities of each event.

Since we are concerned with the probability of either event occurring, conditional probability, which relates to the probability of one event occurring given that the other event has already occurred, is not relevant.

Similarly, multiplying the probabilities of the two events would express the probability of both independent events occurring. Doubling their probabilities would also not be relevant.

Question 19

Which of the following best describes the elasticity of demand for health care in the United States?
A) Perfectly elastic
B) Perfectly Inelastic
C) Relatively Elastic
D) Relatively Inelastic

Answer 19

D) Relatively Inelastic: relatively large changes in price cause relatively small changes in quantity

In other words, quantity is not very responsive to price. More specifically, the percentage change in quantity is less than the percentage change in price.

Question 20

A health behavior survey conducted in a large urban area includes a question about whether a person is a smoker. The company conducting the survey decides to increase the size of its random sample of survey participants from 1,5000 people to approx. 20,000 people. This change will most likely have which of the following effects?

A) Decreasing the variability of the estimate
B) Increasing the standard error of the estimate
C) No effect on survey stats because the population size is the same
D) Increase the CI width for the parameter

Answer 20

A) Decreasing the variability of the estimate

As sample size increases, the range decreases, which means variability decreases.

Question 21

On the basis of the present evidence, the greatest reduction in injuries and death related to motor vehicles in the US is most likely to be a result of which of the following?

A) Stricter motor vehicle inspection laws
B) Modifications to vehicles and highway systems
C) Increase in law enforcement and highway patrol officers
D) Stiffer penalties for drunk drivers and repeat speeders

Answer 21

B) Modifications to vehicles and highway systems

Question 22

Which of the following is the largest source of radiation dose to the general public nation wide?

A) Medical use of x-rays
B) Nuclear Power Plants
C) Radon Gas
D) Nuclear weapons testing fallout

Answer 22

C) Radon Gas

Question 23

Which of the following best describes the tendency for an insured person to overuse health services because he has insurance?

A) Adverse Selection
B) Crowding Out
C) Risk Aversion
D) Moral Hazard

Answer 23

D) Moral Hazard

Question 24

A researcher is calculating the infant mortality rate of several states. Which of the following methods is appropriate to use during this analysis to adjust for racial differences in infant mortality rates among the states?

A) Direct standardization
B) Linear Regression
C) Logistic Regression
D) Life Table Analysis

Answer 24

A) Direct Standardization

The direct method of standardization requires that the age-specific rates for all populations being studied are available and that a standard population is defined.

Logistic Regression: used to describe data and to explain the relationship between one dependent binary variable and one or more nominal, ordinal, interval or ratio-level independent variables.

Linear Regression: used when your response variable is continuous

Life Table Analysis: tool to analyze occurrences of an event through time, presents the proportion surviving, the cumulative hazard function, and the hazard rates of a large group of subjects followed over time

Question 25

In addition to ozone and particulates, which of the following is most likely to aggravate asthma?

A) Sulfur dioxide
B) Carbon Monoxide
C) Asbestos
D) Nitrogen

Answer 25

A) Sulfur Dioxide

Sulfur dioxide causes a range of harmful effects on the lungs, as the EPA’s most recent review of the science concluded…

Question 26

Requiring health care providers to report individual cases of disease as they are diagnosed to state or local health departments is an example of which of the following types of surveillance:

A) Passive
B) Active
C) Syndromic
D) Sentinel

Answer 26

A) Passive Surveillance

Question 27

Public health actions frequently involve a balancing of individual rights vs. the good of the community. Where that balance is struck is based on:

1) Explicit direction found in the Nation’s Constitution
2) Societal Values
3) Science
4) Deontological principles

Answer 27

2) Societal Values

The Constitution does not provide explicit direction when it comes to balancing individual rights and promoting the common good. Public health policy and regulation, although based on scientific evidence and general moral considerations is not likely to be adopted where there is not general consensus and support by the public it serves to protect.

The definition: “Public Health is what we, as a society, do collectively to assure the conditions in which people can be healthy” suggest the need for cooperative actions built on overlapping values and trust.

Question 28

Which of these has been defined as a core function of public health?

1) Maintaining the census to define populations
2) Consulting stakeholders to decide what best serves public interest
3) Conducting research to solve all population health problems
4) Acting in an ethical manner

Answer 28

2) Consulting stakeholders to decide what best serves public interest

Question 29

Which of the following components of a strategic planning process in a public health agency has logical priority over the others? (Key words: Strategic Planning Process)

1) Preparing an action plan for eradicating giardiasis in the municipal water system
2) Developing the operating budget and staffing plan for the agency
3) Reviewing (and revising) the vision and mission statements for the agency
4) Setting strategic goals for a three-year cycle

Answer 29

3) Review (and revising) the vision and mission statements for the agency

The initial activity in the prevailing strategic planning paradigm is the review and (as needed) revision of the organization’s mission and vision statements and its core values. This provides a philosophical foundation for subsequent steps in the strategic planning process.

Question 30

The best multi-platform software product to support public health field investigators who want a program on their portable device capable of generating survey questionnaires and analyzing survey data is:

1) Excel
2) Epi-Info
3) SAS
4) R Statistics

Answer 30

2) Epi-Info

Epi-Info is a public domain product widely used by public health agency staff. Unlike the other statistical analysis software listed, it is unique in supporting creation of questionnaires and transferring data for those questionnaires directly into the tables for analysis.