ACVPM Epidemiology and Biostatistics Practice Exam

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• In Koch's postulates, what must be true about the agent in every case?
• Which of the following is NOT typically listed as a major issue in medical ecology?
• A positive test result with a likelihood ratio of 2.0 implies what about post-test odds?
• Which of the following is NOT a common example of clustered data in veterinary epidemiology?
• Non-informative censoring is an assumption underlying which method?
• What does a 95% confidence interval mean in statistics?
• What are the two types of life tables used in veterinary epidemiology?
• What is true about r and r^2?
• Which Hill criterion requires that the exposure precede the disease in time?
• In a dynamic population where individuals are at risk for varying periods, which measure is used?
• What are the general approaches to analyzing survival data?
• Which statement correctly describes the effect of a series interpretation on sensitivity and specificity?
• Which term describes the variability among results obtained from repeated testing of the same sample within the same lab?
• A descriptive survey can become a cross-sectional analytic study when which condition is met?
• In experimental design, what defines a split-plot design?
• Which of the following describes common methods to evaluate heterogeneity in meta-analysis?
• Which model makes assumptions about ordering of categories and is used with ordinal data?
• Which formula defines attributable risk?
• What is a pandemic?
• How is the desirability of the final outcome expressed?
• Which factors determine changes in positive and negative predictive values of a lab test?
• What is a moving average in time series analysis?
• Which measure describes how many people at risk develop disease within a short period during an outbreak?
• In eradication criteria, what does 'acceptability to industry' refer to?
• Which of the following is a major issue addressed in medical ecology (epidemiology of disease)?
• Which statement best describes a way to quantify time to event in survival analysis?
• What is a receiver operating characteristic curve?
• In a causal diagram, what composes the total causal effect?
• What two variables are found in decision trees?
• Which statistic is recommended for measuring linear association between two tests and why?
• Which description best explains the web of causation in disease?
• Fold back analysis computes expected utility by:
• In the pyramid of causal evidence, are non-controlled experimental studies considered higher or lower than observational studies?
• In a case-only study, which of the following is true regarding interaction effects?
• In survival analysis, which statement describes the Nelson-Aalen cumulative hazard function?
• Biological transmission via vectors is characterized by what?
• What is the first step in a decision-tree analysis?
• Which statement correctly describes nominal, ordinal, and interval data?
• Which of the following best describes Spearman's rho?
• Which methods are used to analyze nominal data with more than two categories?
• In cross-sectional study analysis, which statement best describes the typical comparison?
• When aiming to rule out a disease, which test property should be prioritized?
• Two diagnostic tests are conditionally independent if...
• What does the p-value tell you and what does it not tell you?
• Define incubation period.
• An uncontrolled clinical trial is characterized by which design feature?
• What are two effects geo-referenced data are subject to?
• Which statement best captures the primary study design of epidemiology?
• To maximize sensitivity, which testing interpretation is preferred?
• Define concurrent cohort study.
• The coefficient of variation is commonly used to express what aspect of clinical measurements?
• Which statement describes the continuation-ratio model?
• Which best describes a prevalence survey?
• A potential drawback of case-cohort design is that it is not optimal if which condition holds?
• Which of the following is NOT a criterion of a successful eradication program?
• Which statement correctly describes acquired herd immunity?
• How can detection and performance biases be eliminated in animal trials?
• Which statement best captures a limitation of Koch's postulates when applied to modern pathogens?
• The adjacent category model is used when categories are ordered and somewhat equidistant and assumes that which statement is true?
• Which are the three forms of nonprobability sampling?
• How do you calculate present value from future value in benefit-cost analysis?
• Which is the preferred statistic for risk, incidence or prevalence?
• Which are the three primary sources of bias in case-control studies?
• Which statement best differentiates observational studies from experimental studies?
• Which statement best defines vector-borne transmission?
• What does randomization achieve in experimental studies?
• What is the survival function S(t)?
• The effective contact rate is the product of which two quantities?
• Which statement correctly describes the relationship among efficacy, effectiveness, and compliance in treatment outcomes?
• Koch's postulates are guidelines to demonstrate that an agent causes disease. Which statement is one of the postulates?
• What is the form of the Cox proportional hazards model?
• What is the main difference between test and remove and herd depopulation strategies?
• What is time series analysis in veterinary epidemiology?
• Which statement correctly describes droplet nuclei?
• Which of the following is an example of a multivariate analytical model to examine exposure variables with disease outcomes?
• Does association always imply causation?
• Which term is another name for the relative risk estimate?
• What are secular trends?
• Which of the following are characteristics of survival data?
• Why is the discount rate used when evaluating long-term disease control programs?
• Which statement about the relationship between hazard and survival is true?
• Which statement correctly contrasts innate and acquired herd immunity?
• Two-stage designs are especially efficient when which condition applies?
• Does statistical significance equal clinical significance?
• In a herd depopulation strategy, what triggers condemnation of the entire herd?
• Which statement is NOT a part of risk analysis?
• Which of the following is NOT a method described for depicting spatial distribution of disease frequency?
• Which description best distinguishes explanatory (efficacy) trials from management (effectiveness) trials?
• What bias should be considered in meta-analysis and how do you display it?
• Which statement about the causal web is accurate?
• Fold back analysis starts from which node in the decision tree?
• How do you handle intervening variables in causal diagrams to estimate causal-effect?
• What are the three ways to measure prevalence?
• How is population attributable fraction calculated?
• What is power in a study?
• Case-control studies are preferred in which scenario?
• Define inductive reasoning.
• What effect does multicollinearity have on regression analysis?
• Which of the following is the measure of effect that represents the excess risk in the exposed group compared to the unexposed group (risk difference)?
• Communicability is best described as what?
• Which of the following is an observational study design?
• Which item is not a determinant of the agent in disease causation?
• What is the direct method used for adjusting rates?
• Define latent period.
• Medical ecology versus the life cycle of disease focuses on what?
• Which statement correctly differentiates cross-classified data from hierarchical data structures?
• Which option is NOT considered a descriptive study type?
• Which expression defines statistical power?
• Which statement correctly differentiates anthropozoonoses from zooanthroponoses?
• Name the three allocation methods for treatment assignment and identify which is most prone to selection bias.
• Partial budgeting criterion: Adopt if 1 + 4 > 2 + 3. Given the following values: Additional returns 120; Forgone returns 80; Additional costs 60; Costs no longer incurred 30. Should adopt?
• What is another term for interaction in statistical terms?
• Which elements are involved in benefit-cost analysis?
• Which statement correctly describes survival analysis functions?
• A diagnostic test with very high specificity but moderate sensitivity is most likely to produce which pattern?
• In the pyramid of causal evidence, which ranking correctly lists cohort, case-control, and cross-sectional studies?
• What is the most traditional method to conduct a time series analysis?
• Which function is estimated by the Kaplan-Meier estimator?
• Secondary attack rate measures what?
• What are the most common economic modeling approaches in veterinary medicine?
• Which of the following are the three parts of risk analysis?
• Which statement is true about the component-cause model?
• The contact rate in epidemiology is defined as which of the following?
• Define positive and negative predictive values?
• Which of the following is a decision-analysis technique used to represent choices and consequences with branches and nodes?
• What is the likelihood ratio of a lab test?
• In which study design does the case serve as its own control and is particularly suited when exposure can change over time and the disease has short duration?
• Herd immunity refers to which concept?
• Which set of models are used to model ordinal data?
• What are alternatives to the logit function for binomial or binary data?
• Which statement accurately describes the relationship between probability and utility in decision trees?
• Which statistic is commonly used to quantify the proportion of total variation across studies due to heterogeneity?
• Distinguish descriptive and inferential statistics.
• Which criterion refers to the number of species that can be infected by the agent?
• What is the primary purpose of directed acyclic graphs (DAGs) in epidemiology?
• In veterinary epidemiology, a generation (cohort) life table tracks mortality over what scope?
• Which term describes global spatial patterns across the entire study region?
• In distinguishing between a systematic review and a meta-analysis, which statement is correct?
• Which term best describes a disease that occurs rarely and without a regular pattern?
• Why should clustering be accounted for in statistical analysis?
• Two-stage designs: how is the second stage performed?
• Which statement about relative risk is true?
• Which estimator is the product-limit estimator used to estimate the survivor function?
• Which measure estimates the proportion of disease in the population that can be attributed to exposure?
• Does your sample size go up or down when you want to not only detect but estimate prevalence in a herd?
• Which statement about statistical power is true?
• Define type I (alpha) and type II (beta) errors.
• Which of the following is a criterion for a successful eradication program?
• External validity is best understood as the study’s generalizability to the broader population, contingent upon which prerequisite?
• What are the two types of variation typically considered in veterinary medicine?
• Which statistic best conveys the precision and potential magnitude of the observed effect alongside p-value?
• What is the simplest approach to analysis of recurrence data?
• What is a terminal node in a decision tree?
• Which statement about innate resistance is supported by the definitions?
• Which are examples of mixed models with random effects on an original scale?
• Cross-sectional studies are best suited when which condition holds?
• Which statement correctly describes random variation versus systematic variation (bias)?
• What is the difference between nominal and ordinal data?
• Which factor can affect interpretation of prevalence and incidence?
• Which statement describes the effect of a tenfold reduction in incidence in both exposed and unexposed on RR and AR?
• Which statement correctly describes the relationship between a sufficient cause and a necessary cause?
• Which statement best describes the temporality limitation of cross-sectional studies?
• Which mechanisms describe direct transmission?
• Positive predictive value is defined as...
• What is the denominator in the attack rate definition?
• If the latent period is shorter than the incubation period for an infectious disease, which consequence is most likely?
• Which statement about predictive values and prevalence is true?
• Nonparametric alternative to Pearson's r.
• What are the two methods of measuring incidence?
• Intention-to-treat analysis is defined as...
• Right censoring occurs when
• The interval from exposure to the start of the infectious period is called what?
• Which statement is false about the component-cause model?
• When should you use repeated cross-sectional studies?
• An area under the ROC curve of 0.5 indicates what?
• What makes up the total causal effect in a causal diagram?
• What is defined as a factor associated with an increased likelihood of an event occurring (such as disease)?
• Reverse causation in cross-sectional studies is most likely when which scenario occurs?
• Which expression gives the apparent prevalence?
• The criterion 'single or limited spectrum of disseminating mechanisms that can be manipulated' means...
• Which of the following is NOT a use of risk as described?
• What are non-parametric methods for survival analysis?
• Which method is most formal to identify a secular trend in time series data?
• Which method is used to explain heterogeneity by incorporating study-level covariates?
• Define historical cohort study.
• What does the fourth Koch postulate require?
• Which statement about predictive values depends on disease prevalence?
• What generalized linear mixed model do you use for 1) binary 2) count data?
• What is another name for causal diagrams used to visualize causal relationships in epidemiology?
• Agreement between two tests is best described as:
• Which measure is estimated in cross-sectional data when Poisson regression with robust standard errors is used?
• The basic reproductive number R0 represents what?
• During the analytic phase of an outbreak investigation, what is the main activity?
• If the estimated true prevalence falls outside the 0 to 1 range, what does this indicate?
• In clustered data, observations share common features not accounted by covariates in the model. This describes?
• Which data type can have a true zero point?
• What are survival data?
• During the descriptive phase of an outbreak investigation, which activity is typical?
• Which of the following correctly defines right, interval, and left censoring?
• Which study design is most commonly used in veterinary epidemiology?
• Why should you adjust rates?
• Which statement best defines compliance in a treatment trial?
• Which statement best defines specificity of a diagnostic test?
• Which statement about the cumulative hazard function is correct?
• What is the major difference between epidemiologists and laboratory scientists?
• What is a confounder?
• Which method is commonly used when there is no gold standard for diagnostic test evaluation?
• Crude rates such as incidence and attack rate summarize the effects of which two factors?
• Define what a cause is in epidemiology.
• Which statement best defines descriptive studies?
• What are other names for causal diagrams?
• Which statement correctly defines a time-varying covariate?
• Which measure estimates the amount of disease in the population that would be prevented if exposure were eliminated?
• Misclassification bias is a form of information bias caused by which issue?
• What are the four requirements for using a parametric test (assume normal distribution)?
• What are the two factors that impact Cohen's kappa?
• What are the three types of likelihood ratios for continuous outcomes?
• Which mechanisms describe indirect transmission?
• Do evaluation principles apply the same for screening and diagnostic tests?
• Which statement best defines epidemiology?
• Which option describes a situation where there is a limited number of host species?
• Validity and reliability of clinical measurements are best described as:
• Which of the following is NOT one of the three ways to increase the positive predictive value of a test?
• In a case-cohort study, which measures of association may be used?
• When the disease prevalence in a population increases, what happens to the positive predictive value, and why?
• What term describes the period required for a pathogen to develop inside a vector to become capable of transmission?
• Explain series interpretation of lab tests
• Which two types of literature reviews are commonly discussed, and which is considered more robust?
• Define the standard error of the proportion.
• What differentiates sporadic from epidemic disease?
• Two-way sensitivity analysis is characterized by:
• What are the two broad categories of explanatory (analytic) studies?
• An analyte's index of individuality assesses utility by comparing which quantities?
• In the context of a high basic reproduction number, which statement about induced herd immunity is correct?
• Which statement best describes the relationship between minimal infectious dose and transmission?
• Which hypothesis requires a larger sample size and stronger evidence to reject the null hypothesis?
• What is the purpose of the discount rate in benefit-cost analysis?
• Three ways of reporting disease occurrence in a population?
• When should adjusted crude rates be used?
• What two values determine the product of the concordance correlation coefficient?
• What is the statistical outcome typically used in cross-sectional studies, and how is it analyzed?
• Which measure is useful for choosing a test and interpreting results at the population level, and is related to the predictive value of a test?
• What does hyperendemic indicate in disease occurrence?
• What are the three time periods of the life cycle of a disease agent?
• In a case-cohort design, what serves as the control group?
• What is a causal web?
• What is the equation for sensitivity of a test?
• Which study design is considered the gold standard for assessing treatment effects?
• Which statement describes hierarchical data structures?
• Which measure can describe the burden of disease in the population attributable to exposure?
• Explain parallel interpretation of lab tests
• What is the primary study design of epidemiology?
• Which statement defines relative risk (risk ratio)?
• How do you differentiate a point source from a propagating epidemic using the epidemic curve?
• Which distribution is commonly used for count data with overdispersion, extending the Poisson model?
• What are other names for cohort studies?
• Which expression correctly describes the hazard function in terms of density and survival?
• How is reliability defined in laboratory testing terms?
• In incidence measurement, what is the appropriate denominator?
• What are the three measures used to interpret results of benefit-cost analysis for a decision?
• What are the two broad types of disease agent transmission?
• Which modeling approach can estimate prevalence ratio in cross-sectional data when using regression?
• Which statement correctly defines accuracy in laboratory measurement?
• Case definition is based on metrics?
• What are the three parts of risk analysis?
• What is the typical design in a cross-sectional study?
• Which statement correctly differentiates mode of transmission from route of transmission?
• What does multicollinearity mean in regression analysis?
• Koch's postulates are problematic for which types of diseases?
• A case-case study is a variant of case-crossover that studies the temporal association between time-varying exposure and outcome only in which subjects?
• Partial budgeting includes which components?
• Which of the following is NOT a listed method to analyze decision trees?
• In computing an analyte's index of individuality, which components must be considered?
• Which term describes local spatial patterns of association such as clustering of similar values?
• Which statement is an explicit advantage of the Kaplan-Meier estimator over actuarial life tables?
• The Hausman, McFadden, and Small-Hsiao tests are used to assess which assumption in multinomial logistic regression?
• Which approach describes evaluating diagnostic tests using a gold standard or reference test?
• Which statement correctly describes truncation definitions in survival data?
• How is Pearson r related to coefficient of determination r^2?
• How do you interpret the area under the ROC curve (AUC)?
• A case-only study is appropriate when which condition is true?
• Parametric tests require which of the following?
• Which study design is typically used to measure exposure status in a population at a single point in time?
• How is population attributable risk (PAR) calculated?
• Is an animal carrier automatically a reservoir?
• Major biases that threaten internal validity in clinical trials include which of the following?
• In split-plot design, which statement is true about whole plots and subplots?
• What is the most common form of multivariable analysis for survival data?
• What are common hazard function families in survival analysis?
• Which statement exemplifies an incubatory carrier?
• Which statement correctly describes horizontal transmission?
• Which mechanism is described as an airborne transmission?
• Which statement best defines sensitivity of a diagnostic test?
• When aiming to confirm a disease, which test property should be prioritized?
• How are analytic (explanatory) studies different from descriptive studies?
• Cross-sectional studies are best defined as what type of study?
• What does stratified analysis in survival models do?
• Which statement best describes cohort studies in terms of exposure manipulation?
• Risk profile analysis focuses on:
• In eradication criteria, what does 'acceptability to industry' refer to?
• Which is NOT one of Hill's criteria for causation?
• How is the population attributable fraction (PAF) defined?
• Which statement best describes how experimental studies differ from observational studies?
• Which type of error is most important to minimize in disease detection when missing a case is critical?
• Which strategy would condemn the entire herd upon any positive test?
• Endemic in disease frequency means what?
• Which statement distinguishes a clinical sign from a symptom?
• Which statement correctly defines the coefficient of variation (CV)?
• In the component-cause model, disease occurs when
• Define infectious period.
• What is the most widely accepted conceptual basis for causation in epidemiology?
• Apparent prevalence (or post-test) is defined as...
• What differentiates sentinel species from indicator species?
• Droplets in disease transmission are characterized by which of the following?
• What is the prevention paradox?
• Which four factors should be considered when estimating sample size for a study?
• Which statement best defines clustered data?
• How does switching to parallel interpretation affect overall sensitivity and specificity?
• What statistical test should you first perform prior to determining agreement between two tests, and why?
• Define p-value.
• When do you use Cohen's kappa (range 0 to 1)?
• Can clinical data from a single patient be interpreted without reference to population expectations?
• Intention-to-treat analysis quantifies which concept in clinical trials?
• How do screening and diagnostic tests vary?
• Which scenario makes meta-analysis particularly appropriate?
• In the intervention phase of an outbreak investigation, what is the primary objective?
• Define truncation in survival data.
• In a test and remove strategy, what happens to a test-positive animal?
• Attack rate is defined as the proportion of a defined population affected during an outbreak, with the denominator equal to which of the following?
• In veterinary epidemiology, which statement correctly defines source population, target population, and study population?
• Which of the following are determinants of the agent that causes disease?
• Which statistic is commonly used to quantify variability between paired test results and assess agreement within or between raters?
• Define causal complements in the component-cause model.
• What is the best study design for assessing treatment effects?
• How do you compute adjusted rates with the direct method?
• If efficacy is 0.8 and compliance is 1.0, what is the approximate effectiveness?
• In veterinary epidemiology, a clinical trial is best described as which of the following?
• What does spatial dependence imply about observations that are geographically close?
• Using concurrent controls in a trial helps mitigate biases that arise from time-related changes between groups. True or false?
• In calculating an analyte's index of individuality, which statement best describes the concept?
• Scenario or event trees are used to depict:
• Which method is used to assess the proportional hazards assumption?
• Which practice most directly reduces bias by preserving randomization and blinding in a trial?
• Which statistic quantifies effect size when continuous outcomes are on different scales?
• Define analytic sensitivity and specificity.
• Which analysis approach preserves randomization and estimates treatment effectiveness?
• Which formula correctly computes future value given present value and rate r over n years?
• Which statement best describes the component-cause model?
• In what situations is the attack rate mostly used?
• What are two spatial relationships in statistical terms related to spatial dependence and heterogeneity?
• NOT a form of nonprobability sampling?
• In veterinary epidemiology, which type of control group is generally less biased?
• True prevalence (pre-test) is defined as...
• Which statement best describes the difference between pathogenicity and virulence?
• What is the basis of sampling in cohort versus case-control studies?
• How do scenario trees differ from fold back in terms of probability handling?
• Which is NOT a recommended step in validating a Cox proportional hazards model?
• Using a test with higher specificity while prevalence stays constant will primarily affect which predictive value, and how?
• Which term describes variability among test results obtained from testing the same sample in different laboratories?
• Which statement best describes the effective reproduction number?
• What is the placebo effect?
• Internal validity refers to the extent to which the study’s conclusions are correct for which group?
• What is an epidemic curve?
• What are the two major modes of transmission?
• What can cross-sectional studies measure and what is a key limitation?
• Herd immunity is related to what measure in a population?
• Define the causal-effect coefficient.
• If a diagnostic test is 100% sensitive and 100% specific, the apparent prevalence equals the true prevalence.
• What are the three influences that patterns of disease occurrence reflect?
• The probability of transmission in epidemiology is defined as which of the following?
• If you know the sensitivity and specificity of a test, true prevalence can be estimated by which formula?
• Which term describes a disease type that increases the likelihood of spread within a herd?
• Cost-effectiveness analysis is defined as
• How does prevalence affect Cohen's kappa?
• What is the difference between point and period prevalence?
• Which particle category disperses most efficiently in confined spaces?
• Internal rate of return is defined as
• Which equations describe the false positive and false negative fractions?
• What are the measures of effect estimated from incidence data?
• Define Pearson product-moment correlation coefficient.
• What best defines meta-analysis?
• If the basic reproduction number is high, which level of induced herd immunity is required?
• Which of the following defines attributable risk (risk difference)?
• What are the 3 forms of disease occurrence across time?
• What is the commonly used relationship among prevalence, incidence, and average disease duration?
• Define cyclical and irregular variation in time series analysis.
• Which criterion describes the ability to control or manipulate how the disease spreads?
• What is one reason the placebo effect can occur?
• Which statement best describes the relationship between relative risk and attributable risk?
• Which statement best describes the relationship between prevalence and the predictive value of a test?
• A decision node represents:
• What is the measure of association used in a case-case study?
• What term describes the probabilities that the disease status can be inferred from a test result?
• What are the three phases of outbreak investigation (field epidemiology)?
• In Koch's postulates, what does 'must be isolated and grown in pure culture' imply?
• Which statement best distinguishes incubatory carriers from convalescent carriers?
• How can you capture seasonal fluctuations in time series analysis?
• Which statement best contrasts Pearson correlation with the concordance correlation coefficient when assessing agreement?
• How is reproducibility defined in laboratory terms?
• What are the two mechanisms of airborne transmission?
• Which statement correctly contrasts random variation with systematic variation?
• Which statement describes time-varying covariates?