Epidemiology

What is the main difference between Descriptive and Analytic studies? a)Descriptive studies only examine individuals b) Descriptive studies are experimental c) Descriptive studies do not manipulate exposure d) None of the above

What is the main difference between Descriptive and Analytic studies? *Descriptive studies do not manipulate exposure*

T/F The positive predictive value (PPV) is more influenced by the specificity than the sensitivity of the screening test.

True.

T/F When a test is imperfect, scientists try to strike balance between sensitivity & specificity by plotting a ROC curve (Receiver Operator Characteristic).

True.

# of deaths from a specific cause in a specific time period per 100 deaths from all cause for the same time period is: a) Crude mortality rate b) Age specific mortality rate c) Proportional mortality rate d) Case fatality rate

# of deaths from a specific cause in a specific time period per 100 deaths from all cause for the same time period is: *Proportional mortality rate* aka cause specific mortality rate

A study evaluated the relationship between breast cancer and a woman's history of breastfeeding. The investigator selects women with breast cancer and an age-matched sample of women who live in the same neighborhoods as the women with breast cancer. Study subjects are interviewed to determine if they breastfed any of their children. This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

*Case Control*

Subjects were persons with laboratory-confirmed trichinosis and one healthy friend of each. All subjects were asked about their consumption of pork and other meat products. This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

*Case Control*

What study design can incorporate consecutive and non consecutive participants? a) Case series b) Ecological c) Cross-sectional d) Nested Case-series

*Case series* can incorporate consecutive and non consecutive participants

A study compared the prevalence of back pain among current members of the plumbers and pipe fitters union with that of current members of the bakers and confectionary union. This is an example of ________ a) Ecological b) Retrospective Cohort c) Experimental d) Cross Sectional

*Cross Sectional*

To determine if a traffic light needs to be installed at a busy intersection, you would want to conduct what sort of study to establish driving patterns? a) Prospective Cohort b) Retrospective Cohort c) Experimental d) Cross Sectional

*Cross Sectional*

Which of the following can hinder reliability? a) Differences within individuals in a study b) Differences in reading results by same reader c) Differences in reading results between readers d) All of the above

*Differences within individuals in a study, Differences in reading results by same reader, Differences in reading results between readers* can all hinder reliability.

A study that examines the death rates from cervical cancer in each of the 50 US states in relation to the average percentage of women in each state undergoing annual PAP smear screening. This is an example of ________ a) Ecological b) Retrospective Cohort c) Experimental d) Cross Sectional

*Ecological*

Which of the following is not a descriptive study? a) Cross-secitonal b) Case series c) Ecologic d) Experiment

*Experiment* is not a descriptive study.

What is/are the advantage(s) of a cross-sectional study? a) Good generalizability b) Expensive c) Can infer causality d) Can infer temporality

*Good generalizability* is the advantage(s) of a cross-sectional study

We are conducting a study of obese vs non-obese subjects to see if they develop diabetes over time; subjects can be enrolled at any time during the course of the study. Therefore we can only measure. a) Cumulative Incidence b) Incidence Density c) Incidence Difference d) Risk Difference

*Incidence Density*

Which of the following affects reliability? a) Intra-subject variation b) Intra-observer variation c) Inter-observer variation d) All of the above

*Intra-subject, Intra-observer, & Inter-observer variations* affect reliability.

What are the 2 types of cohorts? a) Static/Dynamic b) Open/Closed c) Forward/Backward d) Person/Animal

*Open/Closed* are the 2 types of cohorts.

___________ can be used for both mortality & morbidity. a) Prevalence rate b) Incidence rate c) A or B d) A & B

*Prevalence rate & incidence rate* can be used for both mortality & morbidity

Vietnamese Experience Study: Subjects were several thousand soldiers stationed in Vietnam from 1969-1971 and several thousand soldiers stationed in Europe from 1969-1971. In the mid 1980s investigators, determined and compared the death rate and prevalence of illness in both groups. This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

*Retrospective Cohort*

A study examined the relationship between exposure to chest irradiation and subsequent risk of breast cancer that was begun in 2005. In this study, women who received radiation therapy for postpartum mastitis (an inflammation of the breast that occurs after giving birth) in the 1940s were compared to women who received a non-radiation therapy for postpartum mastitis in the 1940s. In this prior study, the women were followed for 50-60 years to determine the incidence rates of breast cancer in each group. This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

*Retrospective cohort*

When reviewing a registry, do persons with colon cancer have a history of less physical activity in the 10 years preceding their diagnosis compared with other persons? This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Experimental d) Cross Sectional

*Retrospective cohort*

In epidemiology, analysis of disease pattern is done by all except: a) Person b) Place c) Time d) Situation

*Situation* In epidemiology, analysis of disease pattern is done by: Person, place, time

Which of the following is not an element of a good screening test? a) Validity b) Viability c) Reproducibility d) Reliability

*Validity, Reproducibility, & Reliability* are all elements of a good screening test. Viability is not.

T/F Prevalence affects sensitivity.

???

A disease that crosses international borders is an example of a/an: a) Endemic b) Epidemic c) Pandemic

A disease that crosses international borders is an example of a *Pandemic*

A public nurse provides vaccine to clients at immunization clinic. This is an example of a __________ level of prevention. a) Primary b) Secondary c) Tertiary

A public nurse provides vaccine to clients at immunization clinic. This is an example of a *Primary* level of prevention.

A researcher combined 2 age-specific populations as a standard in order to adjust the study population. This is ______ standardization. a) Normal b) Dynamic c) Direct d) Indirect

A researcher combined 2 age-specific populations as a standard in order to adjust the study population. This is *Indirect* standardization.

A researcher conducted a set of age-specific rates in order to standardize the study population (an SMR was used). This is ___________ standardization. a) Normal b) Dynamic c) Direct d) Indirect

A researcher conducted a set of age-specific rates in order to standardize the study population (an SMR was used). This is *Indirect* standardization.

A study describing the 5 cases of West Nile Virus disease in Tarrant County in 2012 is an example of: a) Case series b) Case-control c) Cross-sectional d) Ecological Study

A study describing the 5 cases of West Nile Virus disease in Tarrant County in 2012 is an example of *Case series*

A study examining the effects of a nearby waste disposal site sampled every fifth house in a series of neighborhoods. This is an example of what type of sampling? a) Systematic sampling b) Stratified sampling c) Simple random sampling d) Quote sampling

A study examining the effects of a nearby waste disposal site sampled every fifth house in a series of neighborhoods. This is an example of *Systematic sampling*

A survey is an example of what type of surveillance? a) Active b) Passive c) Vital d) Statistical

A survey is an example of what type of surveillance? *Active*

According to Framingham Study, disease patterns have shifted frim infectious to chronic (in the US)? a) True b) False

True.

Which of the following is a cross-sectional study? a) A study describing the prevalence of smoking among high school students in Harris county. b) To determine the association between smoking and lung cancer, a researcher compared the smoking histories of 500 subjects with lung cancer and 1000 subjects without lung cancer. c) Two groups of elderly subjects - one group vaccinated, the other group unvaccinated were studied to determine the long-term effectiveness of influenza vaccines in elderly people. d) To determine if a history of abuse was associated with crime, past records were reviewed to establish a correlation.

A. A study describing the prevalence of smoking among high school students in Harris county. *is a cross-sectional study*

A study that examines the death rates from colon cancer in each of the 50 U.S states in relation to the average percentage of residents in each state undergoing colonoscopy screening. This is an example of : a) Ecologic b) Cross sectional c) Case control d) Cohort

A. Ecologic

Ability of a test to distinguish who has a condition/disease and who does not is a) Validity b) Reliability c) Specificity d) Sensitivity

Ability of a test to distinguish who has a condition/disease and who does not is *Validity*

T/F A study describing the prevalence of childhood obesity in Fort Worth is a Cross-Sectional study.

True.

Which of the following is an objective of Epidemiology? a) Identify the frequency of the disease b) Identify the population of the disease c) Identify the etiology of the disease d) All of the above

All of the above Objectives of epidemiology: *D*o *I* *E*ven *C*are? 1) *D*escribe extent of disease--population 2) *I*dentify etiology of disease 3) *E*stablish natural history to predict future occurence 4) *C*ontrol occurrence of disease by developing policy

Which of the following should be considered when calculating sample size? a) Alpha b) Power c) Difference in response rates d) All of the above

All of the above. *Alpha, Power, & Difference in response rates* should all be considered when calculating sample size.

Which of the following is used to express prognosis? a) Case fatality rate b) Median survival time c) Five year survival rate d) All of the above

All of the above. *Case fatality rate, Median survival time, & 5 year survival rate* are all used to express prognosis.

The life table method of survival analysis assumes the following: a) No change (improvement) in treatment b) No significant loss to follow-up c) Stage migration may increase morbidity d) All of the above

All of the above. The life table method of survival analysis assumes *No change (improvement) in tx, No significant loss to follow-up, Stage migration may increase morbidity*

Which of the following is not involved in the WHO definition of health? a) Physical & mental well-being b) Social & mental well-being c) Social & physical well-being d) All of the above are involved

All of the above. WHO Defintion of *Health*: Health is a state of complete physical, mental & social well-being & not merely the absence of disease or infirmity.

An essential characteristic of cohort study is a comparison of outcomes in ________ and _________ groups. a) Dead/Alive b) Diseased/Non-diseased c) Exposed/Unexposed d) Older/Younger

An essential characteristic of cohort study is a comparison of outcomes in *Exposed* and *Unexposed* groups.

An increase in specificity results in a: a) Decrease in PPV b) Increase in PPV

An increase in specificity results in a *Increase in PPV*

T/F Positive predictive value is the likelihood that a patient actually has the disease if they tested positive.

True.

Screening women after the age of 40 for breast cancer is an example of _______ type of prevention. a) Primary b) Secondary c) Tertiary d) None of the above

B--???

T/F Screening is conducted in order to reduce morbidity & improve survival.

True.

T/F The PPV is more influenced by the specificity than the sensitivity of the screening test.

True.

A researcher set out to investigate the relationship between three major allergic diseases, asthma, allergic rhinitis (AR), and atopic dermatitis (AD), and psychological and behavioral problems in preschoolers. He conducted a survey using a modified International Study of Asthma and Allergies in Childhood questionnaire to determine the prevalence of symptoms and diagnosed allergic diseases, and a Korean version of the Child Behavior Checklist to assess internalizing, externalizing, and sleep problems among 780 preschoolers. This is a ____study design. a) Case series b) Case-control c) Cross-sectional d) Ecological Study

C. Cross-sectional

To study the association between knowledge and behaviors related to HIV in high school students, a questionnaire to assess knowledge about prevalence, causes and individual susceptibility to HIV and practice of risky sexual behaviors was administered. This is an example of which type of study? a) Case series b) Case-control c) Cross-sectional d) None of the above

C. Cross-sectional

What are case-studies/case series studies MOST often used for? a) To detect an outbreak b) To determine causality c) To examine the burden of disease in a population d) To establish formal statistical association

Case-studies/case series studies MOST often used *To detect an outbreak*

Cohort studies are best used for ________ whereas, case control studies are best used for _________. a) Rare outcome, rare exposure b) Rare exposure, rare outcome c) Rare outcome, rare disease d) Rare disease, frequent exposure

Cohort studies are best used for *Rare exposure* whereas, case control studies are best used for *Rare outcome*.

Confounding or bias is more common in _________. a) Retrospective studies b) Prospective studies c) Cohort studies d) Case-control studies

Confounding or bias is more common in *Retrospective studies*.

A researcher used data collected from high school students from Baltimore, Maryland, and studies the differences in tobacco use between a cohort of adolescents that worked for pay and a cohort of adolescents that did not work for pay. The results suggest that adolescents who work for pay have a higher risk of using tobacco. This is an example of a ________ study. a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

Cross Sectional

T/F The incidence of the target disease will likely increase when a new screening test becomes widely used.

True.

What is/are the limitation(s) of a cross-sectional study? a) It only measures incidence b) The Healthy-Worker effect c) Preponderance of prevalent cases of long duration d) Both B & C

D. *The Healthy-Worker effect & Preponderance of prevalent cases of long duration* are limitations of a cross-sectional study

A study comparing the prevalence of cardiovascular disease in the US with the prevalence of cardiovascular disease in Japan is an example of _____ a) Case series b) Case-control c) Cross-sectional d) Ecological Study

D. Ecological Study

What if all we know the mortality rate for a particular condition in the general population and we want to know if the mortality rate for that particular condition in a specific occupation is the same as for the general population. We would want to use? a) Direct b) Indirect

Direct

A study assessed the impact of sun exposure on skin damage in beach volleyball players. During a weekend tournament, players from one team were asked to wear waterproof, SPF 35 sunscreen, while players from the other team did not wear any sunscreen. At the end of the volleyball tournament players' skin from both teams was analyzed for texture, sun damage, and burns. Comparisons of skin damage were then made based on the use of sunscreen. This is an example of ________ a) Prospective Cohort b) Retrospective Cohort c) Case-Control d) Experimental

Experimental

T/F A good example of screening is conducting a prostate biopsy in a 50 year old man w/suspected prostate cancer.

False.

T/F Diagnostic tests are essentially the same as screening tests.

False.

T/F Mean survival rate is preferred to median survival rate in expressing prognosis of disease.

False.

T/F Survival studies usually have NO loss to follow up.

False.

T/F The Kaplan Meier method uses predetermined time intervals.

False. Kaplan Meier method uses time events occurred rather than interval of follow up.

T/F The purpose of screening is to identify symptomatic cases of disease.

False. The purpose of screening is to sort out apparently well people who probably have a disease from those who probably do not.

T/F The Kaplan Meir is best suited for common diseases.

False. The Kaplan Meir is best suited for studies w/small # of patients (rare diseases).

For screening to be possible, there is need for: a) Suitable disease b) Suitable test c) Suitable screening program d) All of the above

For screening to be possible, there is need for *Suitable disease, Suitable test, & Suitable screening program*

High prevalence may be due to: a) High incidence b) Prolonged duration c) A or B d) A & B

High prevalence may be due to *High incidence & Prolonged duration*

If a doctor is prescribing a new drug and finds that the recently approved drug actually lacks the efficacy determined in clinical trials, there is a possibility that the original researcher made a _________ error. a) Type I error b) Type II error

If a doctor is prescribing a new drug and finds that the recently approved drug actually lacks the efficacy determined in clinical trials, there is a possibility that the original researcher made a *Type I Error* --concluding there is a difference when there really isn't

In most research, population results are: a) Unimodal b) Bimodal c) Both d) None of the above

In most research, population results are *Unimodal*

In order to screen a disease, it should satisfy which one of the following criteria? a) Disease should have a short latent period b) Disease should not have serious health consequences c) Disease should be progressive d) Prevalence of detectable pre-clinical phase must be low

In order to screen a disease, it should satisfy which one of the following criteria? *Disease should be progressive*

Increase in prevalence leads to which of the following? a) Increase in NPV b) Decrease in NPV

Increase in prevalence leads to a *Decrease in Negative Predictive Value*

If the expected number of deaths between ship builders and farmers is 200 and 70 (per 10,000) respectively and assuming that the observed number of deaths in both populations are 120 and 30 (per 100,000) respectively. What would be the appropriate method of standardization? a) Direct b) Indirect

Indirect

Mr. Arnold goes to local clinic for his annual prostate screening, this is an example of a ______ level of prevention. a) Primary b) Secondary c) Tertiary

Mr. Arnold goes to local clinic for his annual prostate screening, this is an example of a *Secondary* level of prevention.

Mutation is an example of: a) Antigenic shift b) Antigenic drift c) Antigenic selection d) Antigenic change

Mutation is an example of *Antigenic shift*

Non-probability samples are best used for: a) Rare events b) Complex studies c) Population-based studies d) Both A and B

Non-probability samples are best used for *Rare events & Complex studies*

Overall percent agreement is measured by the _____ statistic. a) Alpha b) Beta c) Gamma d) Kappa

Overall percent agreement is measured by the *Kappa* statistic.

A study assessed the impact of sun exposure on skin damage in beach volleyball players. During a weekend tournament, players from one team wore waterproof, SPF 35 sunscreen, while players from the other team did not wear any sunscreen. At the end of the volleyball tournament players' skin from both teams was analyzed for texture, sun damage, and burns. Comparisons of skin damage were then made based on the use of sunscreen. This is an example of ________. a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

Prospective Cohort

To determine the long-term effectiveness of influenza vaccines in elderly people, cohorts of vaccinated elderly and unvaccinated community-dwelling elderly were studied over time. The results suggest that the elderly who are vaccinated have a reduced risk of hospitalization for pneumonia or influenza. . This is an example of a: a) Prospective Cohort b) Retrospective Cohort c) Case Control d) Cross Sectional

Prospective Cohort

Prospective Cohort studies are more likely than Case-Control studies to have problems with: a) Information Bias b) Recall Bias c) Loss to follow up d) Selection bias

Prospective Cohort studies are more likely than Case-Control studies to have problems with *Loss to follow up*

Selection bias is a threat to: a) Internal validity b) External validity c) Reliability d) All of the above

Selection bias is a threat to *External validity*

The measure of central tendency that divides the # of scores in half is: a) Mean b) Median c) Mode d) Range

The measure of central tendency that divides the # of scores in half is *Median*

The measure of disease in which numerator & denominator are mutually exclusive is: a) Count b) Proportion c) Ratio d) Rate

The measure of disease in which numerator & denominator are mutually exclusive is *Ratio*

The test which leads to net gain in sensitivity but net loss in specificity is a) Sequential Testing b) Simultaneous Testing c) Both of the above d) None of the above

The test which leads to net gain in sensitivity but net loss in specificity is *Simultaneous Testing*

The type of statistical test used for smaller data set is: a) Parametric b) Non-parametric

The type of statistical test used for smaller data set is: *non-parametric*

When the age-specific rates for 2 or more groups are known _______ can be applied. a) Direct Standardization b) Indirect Standardization c) Both of the above d) None of the above

When the age-specific rates for 2 or more groups are known *Indirect Standardization* can be applied.

Which of the following is a good definition of epidemiology? a) It is the study of the determinants & distribution of disease b) It is the study of epidemics c) It is the study of medicine and its effect on disease d) It is the study of biological agents that cause disease

Which of the following is a good definition of epidemiology? *It is the study of the determinants & distribution of disease*

Which of the following is not a type of data scale? a) Nominal b) Ordinal c) Parametric d) Interval

Which of the following is not a type of data scale? *Parametric* Nominal, ordinal, & interval are types of data scales.

Who is credited with founding epidemiology as a result of linking a cholera outbreak in London to a public water pump? a) Hippocrates b) John Graunt c) John Snow d) Robert Koch

Who is credited with founding epidemiology as a result of linking a cholera outbreak in London to a public water pump? *John Snow*

Which of the following is a cross sectional study? a) A study describing the prevalence of depression among adult patients with Rheumatoid Arthritis in a hospital survey. b) A study describing prevalence of developmental disorders among children with Autism when mother breastfed through infancy. c) A study describing the prevalence of elevated blood pressure among incarcerated perpetrators of domestic abuse. d) A study describing the prevalence of a history of drug abuse in relation to the long-term compliance with a diet program.

a) A study describing the prevalence of depression among adult patients with Rheumatoid Arthritis in a hospital survey. *cross-sectional study*

A study on gastric cancer is conducted using population data from various major cities across Japan. The researchers find a relationship between salt and gastric cancer in males. They conclude that Japanese men have a higher risk of developing gastric cancer if they consume salt. This inference is: a) Inaccurate inference from population or community results to the individual. b) Inaccurate inference from the study population to the general population. c) Inaccurate inference from one study population to another study population d) Accurate inference

a) Inaccurate inference from population or community results to the individual.