epidemiology

When a P value is less than or equal to which value, we reject the null hypothesis in favor of the alternative because random error is an unlikely explanation of the discrepancy between the results and the null hypothesis? a. 0.05 b. 0.10 c. 0.50 d. 0.01

0.05

which phase of a clinical trial provides metabolic and pharmacologic profiles of the drug a. 1 b. 2 c. 3 d. 4

1

Control-to-case ratios of up to which value help to increase the power of the study? a. 6 to 1 b. 4 to 1 c. 10 to 1 d. 8 to 1

4 to 1

The U.S. Food and Drug Administration (FDA) and the Department of Health and Human Services (DHHS) codified human subjects regulations based on which of the following in 1981? a. Kefauver-Harris Bill b. Declaration of Helsinki c. Belmont Report d. Nuremburg Code

Belmont Report

Modern epidemiologists consider which study to be "a classic exemplar for the investigation of a given outcome and an array of exposures"?

Doll and Hill's Studies on Smoking and Lung Cancer

Which of the following is a judgment in which the investigator applies "the conclusions of a trial to the broader setting of general medical care and to a more heterogenous set of patients than those studied"? a. reliability b. generalizability c. consistency d. validity

Generalizability

Which of the following is an example of an appropriate disease that meets all the criteria for screening? a. HIV b. influenze c. measles d. chickenpox

HIV

The 10 principles outlined in which of the following were among the first rules for experimentation involving human subjects? a. Kefauver-Harris Bill b. Declaration of Helsinki c. Belmont Report d. Nuremberg Code

Nuremberg Code

Because measurement is the cornerstone of epidemiology and "health" and "sense of well-being" are nonspecific and difficult to quantify, epidemiologists have almost entirely focused their activities on which of the following, such as specific disease, injuries, disabilities, and death? a. presence of health b. presence of disease c. absence of disease d. absence of health

absence of health

Risk difference or rate difference is a general term for which of the following? a. absolute comparison b. direct standardization c. relative comparison d. standard comparison

absolute comparison

Which of the following is an increasingly popular form of research in epidemiology that uses computer simulations to study the complex interactions among individuals, their physical and social environments, and time? a. linear regression b. agent-based modeling c. dose-response relationships d. statistical inference

agent-based relationships

which of the following measures is very useful for determining priorities for public health action? a. risk ratio b. risk difference c. attributable proportion among the exposed (APe) d. attributable proportion among the total population (APt)

attributable proportion among the total population (APt)

The focus of research for which type of science is often on the disease mechanism or process?

basic science

because they conduct their studies in a controlled laboratory environment, they can regulate all important aspects a. basic scientists b. clinical scientists c. environmental scientists d. public health scientists

basic scientists

The incorrect failure to reject a false null hypothesis is called which type of error? a. random error b. beta error c. measurement error d. alpha error

beta error

which type of studies are best when little is known about a disease because more than one hypothesis can be evaluated? a. cohort studies b. ecological studies c. case-control studies d. cross-sectional studies

case-control studies

Over the past 3 decades, the traditional view that which type of study is a backward cohort study has been supplanted by a modern view that asserts that it is merely an efficient way to learn more about the relationship between exposure and a disease? a. case-control study b. experimental study c. ecological study d. case-crossover study

case-control study

Which of the following is a method of sampling a population in which researchers identify and enroll cases of disease and a sample of the source population that gave rise to the cases? a. case-control study b. cohort study c. ecological study d. cross-sectional study

case-control study

Which type of study was developed for situations "when brief exposure causes a transient change in risk of a rare-acute onset disease"? a. cross-sectional studies b. ecological studies c. case-control studies d. case-crossover studies

case-crossover studies

Because cases serve as their own controls, which design has several advantages, including the elimination of confounding by characteristics such as gender and race and the elimination of a type of bias that results from selecting unrepresentative controls? a. case-crossover study b. cross-sectional study c. cohort study d. ecological study

case-crossover study

often the first to identify new diseases, adverse effects of new exposures, and links between an exposure and a disease a. basic scientists b. clinical scientists c. environmental scientists d. public health scientists

clinical scientists

which type of study is preferable when little is known about the health consequences of an exposure? a. cohort b. ecological c. case-control d. cross-sectional

cohort

Which type of observational study examines one or more health effects of exposure to a single agent? a. ecological study b. cohort study c. cross-sectional study d. case-control study

cohort study

The mixing of effects between an exposure, an outcome, and a third extraneous variable is referred to as which of the following? a. bias b. confounding c. blocking d. matching

confounding

Which of the following is sometimes confused with effect measure modification because it also involves a third variable in addition to the exposure and disease and is evaluated by conducting stratified analyses? a. confounding b. bias c. random error d. generalization

confounding

Which of the following occurs when individuals who are treated for their condition are compared with individuals who have neither the condition nor the treatment? a. confounding by indication b. positive confounding c. confounding by severity d. negative confounding

confounding by indication

If which of the following occurs in observational studies, it usually makes the therapy appear less effective than it appeared in experimental studies? a. negative confounding b. confounding by severity c. confounding by indication d. positive confounding

confounding by severity

Which type of bias can be avoided by remembering the purpose of the control group? a. recall bias b. information bias c. self-selection bias d. control-selection bias

control-selection bias

Which of the following, a key activity of epidemiologists, includes three steps; developing a definition of disease, instituting a mechanism to account for cases of disease within a specified population, and determining the size of the population?

counting

Which of the following, adapted from an original developed by Richard Monson of Harvard School of Public Health, is believed to "disentangle the skeins of serendipity, bias, and intent that run throughout epidemiologic research"? a. meta-analysis b. journal article c. literature review d. critique outline

critique outline

Which type of studies typically take a snapshot of a population at a single point in time and therefore usually measure the disease prevalence in relation to the exposure prevalence? a. ecological study b. case-control study c. cohort study d. cross-sectional study

cross-sectional study

The "lifetime risk of breast cancer" among women is a commonly cited measure of which of the following? a. cumulative incidence b. incidence rate c. point prevalence d. period prevalence

cumulative incidence

When the excess relative risk associated with having both factors together is larger than the sum of the excess relative risk associated with each factor alone, it can be concluded that there is effect measure modification known as which of the following? a. departure from additivity b. departure from multiplicity c. statistical interaction d. homogeneity of effect

departure from additivity

Synergy is a more general term for which of the following? a. statistical interaction b. homogeneity of effect c. heterogeneity of effect d. departure from multiplicity

departure from multiplicity

Which of the following represents a high level of effect measure modification? a. statistical interaction b. homogeneity of effect c. departure from multiplicity d. departure from additivity

departure from multiplicity

Which group believes that all events are "predestined to unravel in a theoretically predictable way that follows inexorably from the previous pattern of actions"? a. determinists b. idealists c. probablists d. statisticians

determinists

which section of a journal article provides the scientific interpretation of the findings? a. results b. discussion c. conclusion d. materials and methods

discussion

refers to the analysis of disease patterns according to the characteristics of person, place, and time a. disease control b. disease frequency c. disease distribution d. disease determinants

disease distribution

A relative measure of comparison is based on the ratio of two measures of which of the following? a. disease control b. disease distribution c. disease determinants d. disease frequency

disease frequency

Internet surveillance has contributed to the early identification of which of the following, including searches of global media sources such as news wires? a. disease transmission b. disease clusters c. disease progression d. disease outbreaks

disease outbreaks

a person is a member of which type of population only as long as he or she has the defining state or condition? a. fixed population b. dynamic population c. candidate population d. catchment population

dynamic population

Which type of studies are most informative when a new screening program is introduced into an isolated, well-defined population? a. ecological studies b. cohort studies c. experimental studies d. case-control studies

ecological studies

Which type of study can be used "to understand how context affects the health of persons and groups through selection, distribution, interaction, adaption, and other responses"? a. case-control study b. ecological study c. case-crossover study d. experimental study

ecological study

Which type of study evaluates an association using the population rather than the individual as the unit of analysis? a. case-control study b. cohort study c. cross-sectional study d. ecological study

ecological study

A shift in which of the following often occurs when a clear benefit or adverse effect is observed for the test treatment in an interim data analysis from the ongoing trial? a. confounding b. validity c. equipoise d. bias

equipoise

The attributable proportion among the exposed, a measure of comparison that expresses the public health impact of an exposure as a proportion, is also referred to as which of the following? a. prevented fraction b. epidemiologic fraction c. incident fraction d. etiologic fraction

etiologic fraction

The high degree of validity in which type of study stems mainly from the investigator's ability to randomize subjects to either the treatment group or the comparison group and thereby control for distortions produced by confounding variables? a. ecological study b. case-crossover study c. experimental study d. cohort study

experimental study

The evaluation of which of the following requires review of the study methods, the makeup of the study population, and subject-matter knowledge (such as the biological basis of the association)? a. specificity b. external validity c. internal validity d. sensitivity

external validity

Because observational studies are often infeasible because of difficulties enrolling participants, high costs, and thorny ethical issues, most epidemiological research is conducted using experimental studies. a. true b. false

false

Epidemiological studies that try to determine the relationship between an exposure and a disease are immune to the disturbing influences of extraneous factors known as confounders. a. true b. false

false

The statements "statistically significant" and "not statistically significant" indicate that the null hypothesis is true.

false

True or False? A confounding variable can be an intermediate step in the causal pathway between the exposure and the disease.

false

True or False? Confounding can be thought of as a failure of the exposed group to reflect the counterfactual experience of the comparison group.

false

True or False? Investigators in a retrospective cohort study can usually obtain more detailed information on exposures and other key variables because they have more control of the data collection process and can gather information directly from the participants.

false

True or False? It is difficult to interpret absolute and relative measures based on summary rates when the compared groups differ on a characteristic that affects the rate of disease?

false

True or False? Like bias and confounding, effect modification is a natural phenomenon of scientific interest that the investigator needs to eliminate.

false

True or False? Recall bias can only occur in prospective studies that gather data from study subject?

false

True or False? The frequency of most diseases decreases with age.

false

True or False? The incidence rate is based upon the assumption that everyone in the candidate population have been following for a specified period of time.

false

True or False? When the direction of the bias is toward the null, it means that the error causes the true measure of association to be overestimated.

false

a case-control study is the most efficient design for studying the health effects of rare exposures

false

it is possible to obtain a valid estimate of disease prevalence from a typical case-control study

false

loss-to-follow-up can be a problem in observational studies but not experimental ones

false

mortality data are adequate for examining nonfatal disease and give a complete picture of health status of a population

false

observational studies suffer that same ethical and feasibility issues as experimental studies

false

public health scientists focus their research on disease diagnosis, treatment, and prognosis in individual patients

false

when calculating the incidence rate of a disease, it is necessary to follow all subjects for the same length of time

false

when chance, bias, and confounding have been ruled out as explanations for an association, we may conclude causation

false

Exposures in which type of cohort do not change over time and are followed from a defined starting point to a defined ending point but may suffer from losses to follow-up? a. fixed cohort b. closed cohort c. dynamic cohort d. open cohort

fixed cohort

cumulative incidence is mainly used in which type of populations where there are no or small losses to follow-up? a. fixed population b. dynamic population c. candidate population d. catchment population

fixed population

people in Hiroshima, Japan when the atomic bomb exploded at the end of World War II are which type of population? a. fixed population b. dynamic population c. candidate population d. catchment population

fixed population

Which of the following is often selected from professional groups such as doctors and nurses, volunteers, or residents in well-defined geographic areas to facilitate follow-up and accurate ascertainment of the outcomes under study? a. special cohort b. open cohort c. general cohort d. fixed cohort

general cohort

Which type of comparison group is commonly used in occupational studies of mortality because these data are quite accessible to researchers? a. comparison group b. general population c. internal comparison group d. external comparison group

general population

The period of increased risk following the exposure is referred to as which of the following? a. hazard period b. latent period c. critical period d. induction period

hazard period

Effect measure modification, also known as which of the following, means that the strength of the association between an exposure and a disease differs according to the level of another variable? a. simple visual inspection b. heterogeneity of effect c. homogeneity of effect d. statistical interaction

heterogeneity of effect

Which term is used when effect modification is absent? a. homogeneity of effect b. heterogeneity of effect c. statistical interaction d. simple visual inspection

homogeneity of effect

The main disadvantage of using which type of control is the difficulty in determining appropriate illnesses for inclusion? a. dead controls b. population controls c. hospital and clinic controls d. friend/spouse/relative controls

hospital and clinic controls

Which of the following is considered a "uniform decision-making criterion" for evaluating random error that is superior to subjective impressions of the data? a. dose-response relationship b. agent-based modeling c. hypothesis testing d. statistical inference

hypothesis testing

Which of the following takes into account the specific amount of time that the members of a population are followed until they develop the disease? a. morbidity b. incidence c. mortality d. prevalence

incidence

When investigators measure which rate in a particular population, random errors may occur during the process of identifying cases of disease or calculating person-time of follow-up? a. morbidity rate b. incidence rate c. mortality rate d. prevalence rate

incidence rate

Which of the following is the appropriate measure of disease frequency in a fixed cohort when the population experiences losses to follow-up? a. incidence rate b. prevalence rates c. cumulative incidence rates d. mortality rates

incidence rates

The process of gaining the agreement of all eligible and willing individuals to participate in an experimental trial is referred to as which of the following? a. expressed consent b. implied consent c. explicit consent d. informed consent

informed consent

Like other types of cancer, a malignancy in the breast is thought to develop through a multistage process known as carcinogenesis. Which of the following represents the first step in this process? a. progression b. initiation c. mutation d. promotion

initiation

Epidemiologists have found that which type of comparison group is the best type of comparison group to use in a cohort study? a. internal comparison group b. general population c. comparison cohort d. external comparison group

internal comparison group

If systematic bias, confounding, and random error have been ruled out as alternative explanations, the investigator may conclude that the association is true and the study has which of the following? a. specificity b. internal validity c. external validity d. sensitivity

internal validity

The most marked declines in HIV diagnoses from 2005 to 2014 occurred in which patient population? a. women b. heterosexuals c. intravenous drug users d. homosexuals

intravenous drug users

adherence to which ethical principle helps determine whether the burden and benefits of research are distributed fairly a. justice b. autonomy c. beneficence d. nonmaleficence

justice

Which type of bias overestimates the benefit of screening and needs to be taken into account when evaluating a screening program? a. information bias b. volunteer bias c. lead-time bias d. length-bias sampling

lead-time bias

Which type of bias makes a screening program appear to have a beneficial effect on survival because people who are destined to have a favorable course are selectively identified? a. volunteer bias b. lead-time bias c. length-bias sampling d. information bias

length-bias sampling

The use of placebos permits which of the following of study participants and investigators, so both are unaware of the participant's treatment assignment? a. blocking b. standardization c. masking d. stratification

masking

Which of the following is needed when the confounder is a complex nominal variable, such as occupation, neighborhood, or familial characteristic such as sibship? a. randomization b. matching c. restriction d. standardization

matching

Which measure of association is commonly used when the data are continuous? a. odds ratios b. risk differences c. mean differences d. rate differences

mean differences

Which of the following is the middlemost observation of the distribution, that is, the observation in which 50% of the observations fall above it and 50% of the observations fall below it? a. standard deviation b. median c. mode d. mean

median

compares the rates of disease among natives of a homeland to rates among immigrants and natives of the adopted country a. cohort studies b. migrant studies c. case-control studies d. longitudinal studies

migrant studies

Defining the exposure and disease using sensitive and specific criteria is a method of reducing which of the following? a. control-selection bias b. interviewer bias c. misclassification d. self-selection bias

misclassification

Biomarkers such as serum micronutrient levels, which can determine a person's fruit and vegetable intake more accurately than can personal interviews, are used in which field of modern epidemiology?

molecular epidemiologists

Which of the following is a general word that can apply to a disease, condition, or event? a. morbidity b. incidence c. mortality d. prevalence

morbidity

Which of the following provide information on the ultimate effect of a disease? a. natality data b. incidence data c. mortality data d. morbidity data

mortality data

Which of the following involves the construction of a mathematical model that describes the association between the exposure, disease, and confounders? a. matched analysis b. standardization c. multivariable analysis d. randomization

multivariable analysis

Which of the following along with state and local surveillance programs serve as the primary data sources on the descriptive epidemiology of elevated blood lead levels among U.S. children? a. behavorial risk factor surveillance system b. national health and nutrition examination survey c. national health interview survey d. national survey of family growth

national health and nutrition examination survey

Which of the following, which is probably the most common form of bias in epidemiological research, biases the results toward the null if the misclassified exposure variable is dichotomous? a. selection bias b. differential misclassification c. non differential misclassification d. information bias

non differential misclassification

The failure to observe the requirements of a study protocol is known as which of the following, and this may occur in the treatment group, the comparison group, or both? a. disobedience b. noncompliance c. maladjustment d. noadherence

noncompliance

Which of the following is the bane of an investigator's life because it results in a smaller difference between the treatment and comparison groups than truly exists, and reduces the statistical power of the study? a. nonadherence b. disobedience c. noncompliance d. maladjustment

noncompliance

One of the earliest associations between which of the following and disease was observed almost 200 years ago by Dr. Percivall Pott, who noted that London chimney sweeps had a high rate of scrotal cancer? a. socioeconomic status b. occupation c. gender d. race

occupation

Which of the following quantifies the compatibility of the study data with the null hypothesis? a. odds ratio b. p value c. risk ratio d. confidence interval

p value

Which of the following refers to the proportion of the population that is diseased during a specified duration of time, such as the year 2017? a. cumulative incidence b. period prevalence c. point prevalence d. incidence rate

period prevalence

Which type of distribution is frequently used in epidemiological research because many diseases are uncommon, particularly if one considers the likelihood of occurrence in a short period of time? a. normal distribution b. binomial distribution c. gaussian distribution d. poisson distribution

poisson distribution

Because of the manner in which what type of controls are identified, investigators are usually assured that they come from the same base population as the cases do? a. friend, spouse, and relative controls b. hospital or clinic controls c. dead controls d. population controls

population controls

which helps which exposures are most important to a given population and to prioritize prevention activities? a. risk difference b. prevalence difference c. incidence rate difference d. population risk difference

population risk difference

If the true risk ratio is 1.0 and the confounded risk ratio is 2.0, this is an example of which of the following? a. negative confounding b. confounding by indication c. positive confounding d. confounding by severity

positive confounding

Which of the following measures can be thought of as the lack of random error? a. reliability b. validity c. precision d. accuracy

precision

Which of the following is useful for estimating the needs of medical facilities and allocating resources for treating people who already have a disease? a. prevalence b. morbidity c. incidence d. mortality

prevalence

which of the following depends on the rate new cases develop as well as the duration that the cases have the disease? a. incidence b. prevalence c. morbidity d. mortality

prevalence

Which of the following can be calculated when an exposure is thought to protect against the disease? a. etiologic fraction b. prevented fraction c. incident fraction d. epidemiologic fraction

prevented fraction

Which type of trials may involve behavior modifications such as dietary improvements, reducing substance use and antisocial behavior, and physical exercise? a. preventive trials b. therapeutic trials c. crossover trials d. parallel trials

preventive trials

which mathematical theory provides the basis for making statistical inferences? a. distribution b. elimination c. probability d. singularity

probability

Which type of epidemiologist believes that random error, or chance, is an important, even chief, explanation for events? a. determinsts b. idealists c. probablists d. statisticians

probablists

Writing understandable questions is both an art and a science, which falls under which discipline? a. isometrics b. psychometrics c. ergonomics d. biometrics

psychometrics

The units of concern for which type of scientist are groups of people living in the community rather than separate individuals visiting a healthcare facility?

public health scientists

Which of the following is considered unsystematic because it arises from an unforeseeable and unpredictable process? a. bias b. confounding c. random error d. generalization

random error

Which of the following leads to a false association between the exposure and disease that arises from chance, an uncontrollable force that seems to have no assignable cause? a. bias b. confounding c. random error d. generalization

random error

A unique advantage of which of the following is that it will control for variables that the study investigator is unable to measure? a. stratification b. randomization c. standardization d. generalization

randomization

an advantage of which of the following is that it will control for variables that investigators are unable to measure? a. matching b. restriction c. randomization d. literature review

randomization

except for which of the following, it is impossible to control for a confounder without data? a. matching b. restriction c. standardization d. randomization

randomization

The most common method for minimizing which type of bias is to select a diseased control group? a. control-selection bias b. interviewer bias c. recall bias d. self-selection bias

recall bias

Which of the following refers to the group of people to whom the study results may be applied or generalized? a. reference population b. catchment population c. index population d. candidate population

reference population

Which of the following gives information about the strength of the relationship between the exposure and disease and is most useful for etiologic research? a. direct standarization b. standard comparison c. relative comparison d. absolute comparison

relative comparison

Tay-Sachs disease, a degenerative disease of the brain and nervous system, is an example of how which of the following can influence disease rates? a. gender b. age c. religious affiliation d. occupation

religious affiliation

Which of the following is based on the conviction that "individuals should be treated as autonomous agents" and that "persons with diminished autonomy are entitled to protection"? a. beneficence b. nonmaleficence c. justice d. respect for persons

respect for persons

If investigators use which of the following to control for confounding in the design phase, this means that admissibility criteria for study subjects is limited? a. restriction b. randomization c. matching d. standardization

restriction

Which section of a journal article describes the characteristics of the study population and study findings and typically includes text, several tables, and figures? a. introduction b. materials and methods c. abstract d. results

results

which of the following describes the public health impact of the exposure among the exposed? a. risk difference b. prevalence difference c. incidence rate difference d. population risk difference

risk difference

Which sampling approach involves longitudinally sampling controls throughout the follow-up period? a. cluster sampling b. case-base sampling c. risk set sampling d. survivor sampling

risk set sampling

which efforts do not prevent disease but identify asymptomatic individuals between the onset and occurrence of symptoms? a. health promotion b. primary prevention c. secondary prevention d. tertiary prevention

secondary prevention

If lost individuals are more or less likely to be exposed than those successfully traced, the study results may suffer from which of the following? a. counterfactual ideal b. selection bias c. information bias d. confounding

selection bias

which type of bias can occur in cohort and experimental studies from differential losses to follow up? a. recall bias b. interviewer bias c. information bias d. selection bias

selection bias

The best way to ensure that which type of bias does not occur is to obtain high participation rates among both cases and controls? a. control-selection bias b. self-selection bias c. information bias d. recall bias

self-selection bias

the best way to ensure that which type of bias does not occur is obtain high participation rates for cases and controls? a. recall bias b. information bias c. self-selection bias d. control-selection bias

self-selection bias

Which of the following is assembled to study the health effects of rare exposures, such as uncommon occupational chemicals? Special a. special cohort b. fixed cohort c. general cohort d. open cohort

special cohort

Which of the following involves taking weighted averages of the relevant measures of disease frequency? a. multivariable analysis b. stratification c. randomization d. standardization

standardization

During the third phase of biostatistical history, between World Wars I and II, R.A. Fisher developed theoretical models for which of the following, a method for generalizing results from a sample to a population? a. dose-response relationships b. statistical inference c. agent-based modeling d. linear regression

statistical inference

In which of the following is the parent population first divided into subgroups, then a random sample is selected from each subgroup? a. clustered random sample b. nested random sample c. simple random sample d. stratified random sample

stratified random sample

Which term includes both surveillance, whose purpose is to monitor aspects of disease occurrence and spread that are pertinent to effective control, and epidemiological research, whose goal is to harvest valid and precise information about the causes, preventions, and treatments for disease? a. trial b. study c. hypothesis d. monitoring

study

Direct standardization is one method for calculating which type of rates? a. summary rates b. attributable rates c. relative rates d. crude rates

summary rates

When which type of sampling is used, the odds ratio estimates the risk ratio in the base population? a. survivor sampling b. case-base sampling c. cluster sampling d. risk set sampling

survivor sampling

Which of the following occurs when two factors work in concert to produce more disease than one would expect based on the action of either factor working alone? a. synergy b. precision c. antagonism d. validity

synergy

control of insulin levels and patient education to prevent retinopathy among patients with diabetes is an example of: a. health promotion b. primary prevention c. secondary prevention d. tertiary prevention

tertiary prevention

The guidelines for Good Clinical Practice (GCP) from which of the following offer an international ethical and scientific quality standard for the design, conduct, recording, and reporting of trials involving human subjects? a. the Department of Health and Human Services (DHHS) b. Institutional Review Board (IRB) c. U.S. Office for Human Research Protection (OHRP) d. The International Conference on Harmonization (ICH)

the International Conference on Harmonization (ICH)

Which type of trial is commonly called clinical trials because they are conducted in a clinical setting among diseased patients and often use a clinical outcome measure, such as recurrence or side effects? a. crossover trials b. therapeutic trials c. preventive trials d. parallel trails

therapeutic trials

A small P value means that the alternative hypothesis is a better explanation for the results than the null hypothesis.

true

Because the significance level is an arbitrary cutoff, it is possible to incorrectly reject or not reject the null hypothesis.

true

Both the cross-sectional and ecological designs have important limitations that make them less scientifically rigorous than cohort and case-control studies. a. true b. false

true

True or False? A statistically significant result has been arbitrarily defined as a P-value less than 0.05 or a 95% confidence interval that does not include the null.

true

True or False? A unifying framework for thinking about a population is whether its membership is permanent or transient.

true

True or False? Because its presence depends on the particular measure of association, effect measure modification should be described using terms that specify the measure.

true

True or False? Because random samples are uncommon in epidemiological research, many epidemiologists question the use of P-values and confidence intervals in observational studies.

true

True or False? Bias can be introduced at any stage of a study, including during the design, data collection, analysis, or even publication stage.

true

True or False? Disease frequencies can be compared between different populations or between subgroups within a population.

true

True or False? Epidemiological studies of the relationship between an exposure and a disease are susceptible to the disturbing influences of extraneous factors called confounders.

true

True or False? Even when clear-cut criteria are used, disease definitions often change over time as more is learned about a disease and its various manifestations.

true

True or False? Experimental studies are commonly classified by their objective, that is, by whether they investigate a measure that prevents disease occurrence or a measure that treats an existing condition.

true

True or False? If the rate of disease among migrants approaches that of the host country, epidemiologists hypothesize that environmental factors may cause the disease.

true

True or False? In the 2010 U.S. Census, "Some Other Race" represented the third largest race group primarily because almost half of Hispanic or Latino respondents do not identify within any of the racial categories as defined in the U.S. Census.

true

True or False? Observational studies are considered "natural" experiments because the investigator acts as a disinterested observer, merely letting nature take its course.

true

True or False? Observational studies provide information on exposures that occur in natural settings, and they are not limited to preventions and treatments.

true

True or False? P-values are confounded statistics because they simultaneously reflect the magnitude of the association and the study size.

true

True or False? Publishing in scientific journals is a major avenue for communicating the results of epidemiological studies.

true

True or False? Retrospective studies are more susceptible to bias than prospective studies because of differences in the timing of the study.

true

True or False? Statistical power measures the ability of a test to correctly reject the null hypothesis when the alternative hypothesis is true.

true

True or False? The attributable proportion is used when an exposure is considered to be a cause of the disease.

true

True or False? The classic analytic approach for an experimental study is known as a treatment assignment analysis.

true

True or False? The timing of prospective cohort studies is similar to that of experimental studies?

true

True or False? When effect measure modification is present using a ratio measure, it will usually be absent when a difference measure is used.

true

a retrospective cohort study is more efficient than prospective for disease with a long latent and induction period

true

a study must be valid before its results can be generalized

true

an advantage of a randomized clinical trial is that it rules out self-selection to the different treatment groups

true

crude rates are summary measures of disease frequency that are based on the raw data

true

ecological studies can be done quickly and inexpensively because they often rely on preexisting data

true

location of residence, such as country, state, city, is one of the most common ways to define a population

true

masking guarantees comparable follow-up efforts and outcome ascertainment, which in turn helps ensure valid results

true

public health has had a greater effect on the health of populations than medicine has had

true

race and ethnicity have a profound influence on disease patterns and can be particularly difficult to measure

true

regardless of the way it is defined, a population can be divided into subgroups on the basis of any characteristic

true

the ecological fallacy states that associations on the group level will not necessarily be present indivdually

true

the primary purpose of the census is to assign members of the House of Representatives to the states

true

when a new prevention measure id developed, both incidence and prevalence of the disease will decrease over the long term

true

To compare disease frequencies, epidemiologists first organize the data into which format? a. histogram b. scatterplot c. pie chart d. two-by-two table

two-by-two table

a general cohort would be assembled to study which of the following? a. medical procedures b. use of oral contraceptives c. unusual diets and lifestyles d. health effects of rare exposures

use of oral contraceptives

the compiler of statistical abstracts for the general registry office in great britain from 1839 through 1880 a. john snow b. james lind c. john graunt d. william farr

william farr

Which of the following measures reflects both the number of individuals who died of a particular cause and the age at which the death occurred? a. age-specific mortality rate b. crude mortality rate c. cause-specific mortality rate d. year of potential life lost

year of potential life lost