Public Health Midterm
Which of the following is not a way health indicators are used? A. Support intervention planning B. Track progress toward broad community objectives C. Engagement of partners into civic and collaborative action D. Inform policy and policy makers E. All of the above
E. All of the above
True or False: A Type I (alpha) errors is a false negative and, in this error, you will not reject null hypothesis when null hypothesis is false.
False. Type I (alpha) errors are FALSE POSITIVES. With Type I (alpha) errors, you will accept the null hypothesis when it is true. (aka you're saying there's no relationship when there is one.. so it's an error)
True or False: if you use a high prevalence population to give a screening test to, you will have a low PPV.
False. the prevalence of disease in a population is directly related to the positive predictive value of the disease. Thus, a low prevalence population will give you a low PPV. A high prevalence population will give you a high PPV. This is because the more prevalent a disease is in a population, the higher the likelihood that the positive screen will be because a person has the disease.
What is the single best way to prevent bias?
Randomization Random selection of subjects in observational studies. Randomly assign treatments to subjects in clinical trials.
T or F: Sensitivity is the likelihood of a population that HAS a disease will be correctly identified by a screening test.
TRUE Sensitivity = People have the disease, the screening test can pick it up and comes back positive - A highly sensitive test will have a high number of True Positives, and a low number of False Negatives Specificity = People don't have the disease, the screening test will come back negative Sensitivity and specificity both are indicators of Validity
What is the epidemiological transition?
The shift of patterns of disease in a country from acute infectious diseases to chronic, degenerative diseases. This is a good thing because the more acute and infectious disease, the higher the more burden of disease and the higher the mortality
T or F: A test with a high sensitivity but low specificity results in a test with a lot of false positives.
True
T or F: Odds Ratio can be interpreted as Relative Risk if the event/disease is rare.
True
True or False: The primary authority for health is reserved to the states
True
What are the 4 things that make for a good epidemiologic research design?
1. Enables a comparison of a variable b/w 2 or more groups 2. Allows that comparison to be quantified 3. Can determine temporality (Which came first?) 4. Minimizes bias, confounders, and other things that can complicate interpretation of results
What are the characteristics of a disease that would make it good for screening?
1. No overt sx 2. Can be discovered and addressed early (before sx begin and tx makes a difference) 3. Is an important health issue 4. Untreated preclinical phase almost always leads to disease
What makes public health controversial? A. It utilizes human subjects in testing B. It acknowledges economic and social health disparities C. It puts a strain on communities D. Its use is not effective
B. It acknowledges economic and social health disparities The expansive view of public health acknowledges that health is influenced by economic and social conditions and challenges society to provide a fair distribution of benefits to all citizens.
In which of the following study designs is a treatment or intervention NOT used? A. Quasi-experimental B. Experimental C. Observational D. Randomized Controlled Trial
C. Observational
T or F: Experimental studies provide information on exposures that occur in natural settings
False. Observational studies give insight into exposures that occur in natural settings
Which of the following Odds Ratio values indicate that there is a protective relationship between the exposure and the outcome? A. 0 B. 1 C. 2 D. 3
A. 0 If the OR < 1, there is a protective or inverse relationship b/w the exposure and the outcome. This also means that the odds of new disease are less in the exposed group than the unexposed group during a specific period of time. ____________________ OR = 1, Odds of new disease are identical in both groups during time t; NO RELATIONSHIP between exposure and outcome OR > 1 Odds of new disease is greater in exposed than in the unexposed group during time t; DIRECT relationship between exposure and outcome
Which of the following is not a limitation of Ecological studies? A. Can't validate statistical association B. inability to detect confounding factors C. correlational data only notes average experience and not individual values D. lack of individual info causes ecological fallacy E. Cant detect complicated relationships
A. Can't validate statistical association This is a limit of case report/series tests.
Which of the following is not a correlational study? A. Case series B. Ecological studies C. Cross-sectional D. All of the above are correlational studies
A. Case series Only ecological and cross-sectional studies are correlational meaning that their results can indicate a correlation between 2 or more things. A case-series does not validate statistical association, so it cannot show a correlation. Correlational studies: - assess exposure and disease SIMULTANEOUSLY. - establish STRENGTH and DIRECTION of association b/w exposure and disease - used to generate hypothesis NOT test causality
Which of the following can grant permission to use data collected in public health? A. IRB B. FDA C. Congress D. State officials
A. IRB The use of data requires permission from an institutional review board or data protection committee
Which of the following is not a factor that affects Reliability? A. Inter-individual variation B. Biological variation C. Instrument variation D. Inter-observer variation E. Intra-observer variation
A. Inter-individual variation It is INTRA-individual variation that affects Reliability ___________________________ The factors that affect Reliability: Biological variation - e.g. - BP normally varies in pts Instrument Variation/Intra-individual Variation - e.g. - can happen with BP Inter-observer Variation - e.g. - 2 radiologists read a mammogram differently Intra-observer Variation - e.g. - the same radiologist reads the film differently
Which of the following functions is NOT done by Local Public Health Agencies? A. Providing laboratory services B. Day-to-day public health tasks C. Core public health functions D. Providing medical care for the poor
A. Providing laboratory services This function is performed by State Health Departments Other Functions of State Health Depts: - Coordinating activities of local agencies and providing funding - Collecting and analyzing data provided by local agencies - Providing laboratory services - Managing Medicaid - License and certify medical personnel, facilities, and services - Handling env, mental health, social services, and aging issues (poss through separate state agencies) - Provings funding to hospitals to reimburse them for treating uninsured patients
Which of the following study designs can attribute to causality? A. Quasi-experimental B. Case-control C. Cohort D. Cross-sectional E. Randomized Controlled Trial
A. Quasi-experimental
Which of the following is not an advantage of a qualitative study? A. Takes a short time to collect data B. Useful for describing complex phenomena C. Flexibly D. Rich and exploratory in nature E. Meaningful and culturally salient to the participant
A. Takes a short time to collect data Qualitative studies actually take a long time to collect data, which is one of their disadvantages. Disadvantages of qualitative studies are: - findings might not be generalizable - cant test hypotheses - info needs to be confirmed by survey research - takes more time to collect and analyze - more easily influenced by bias
Which statistical error is a false positive? A. Type I error B. Type II error C. Beta error D. Delta error
A. Type I error All statistical hypothesis tests have the probability of making type I and type II errors In testing a null hypothesis (H0), you have two possible decisions: Reject or Accept the null hypothesis Type I error (α error) - Also known as false positive Rejection of H0 when the H0 is true Example - analysis showed that memorization is related to good grades, when it really does not. Type II error (β error) - Also known as false negative Not rejecting the H0 when the H0 false Example - analysis showed that studying is not related to good grades, when it really does
You are creating a research study to test the prevalence of gonorrhea in Jamaica, Queens. Which of the following research designs would you utilize to perform this study? A. cross-sectional B. case-control C. case report D. case series E. cohort
A. cross-sectional Whenever you see PREVALENCE, think CROSS-SECTIONAL.
Which of the following Odds Ratio values indicate that there is no relationship between exposure and outcome? A. 0 B. 1 C. 2 D. 3
B. 1 When OR = 1, Odds of new disease are identical in both groups during time t; NO RELATIONSHIP between exposure and outcome ______________________ OR > 1 Odds of new disease is greater in exposed than in the unexposed group during time t; DIRECT relationship between exposure and outcome OR < 1 Odds of new disease is less in exposed group than in unexposed group during time t; PROTECTIVE or INVERSE relationship between exposure and outcome
Which of the following is one of the 3 Core functions of Public Health? A. Accountability B. Assessment C. Policy differentiation D. Applicability
B. Assessment The three Core Functions of Public Health: Assessment Policy development Assurance
Which of the following is the most frequently used study design? A. Case series B. Case-control C. Cohort D. Cross-sectional
B. Case-control
Which of the following study designs is most likely to give you recall bias? A. Case series B. Case-control C. Cohort D. Cross-sectional
B. Case-control
In which study design would you select participants based on whether or not they are diseased? A. Case series B. Case-control C. Cohort D. Cross-sectional
B. Case-control In case-control studies, we know the disease. We don't know the exposure. Because participants are selected on the basis of disease, exposures for ALL PARTICIPANTS are obtained RETROSPECTIVELY. You want to know what caused the disease. Strengths: - Good test for RARE diseases. - Tends to support causal hypothesis by establishing associations Limitations: - Possible bias b/c based on recall of participants - Cant calculate incidence - Controls are hard to select - Data from previous work may be incomplete
Which of the following observational studies only looks backward? A. Case series B. Case-control C. Cohort D. Cross-sectional
B. Case-control Which is why it has the highest recall bias
Which of the following study designs is best to measure the association of Relative Risk and Rate Ratio? A. Case series B. Cohort C. Case control D. Cross-sectional
B. Cohort RR = COHORT
The U.S. Census is considered what type of study? A. Cohort B. Cross-sectional C. Ecological D. RCT
B. Cross-sectional
Which of the following studies would best be used for building hypotheses as well as healthcare and education planning? A. Cohort studies B. Cross-sectional C. Randomized controlled trials D. Case-control
B. Cross-sectional Cross-sectional is a descriptive study design. Any descriptive study design would be useful for: - describing patterns of diseases in terms of person, place or time - healthcare and education planning - providing clues about determinants of a disease - building hypotheses
Which one of the following is not one of the top federal agencies involved in public health? A. FDA B. EPA C. CDC D. NIH
B. EPA The EPA deals with environmental issues
Which of the following study designs is presented via summary statistics such as mean, median, or mode? A. Case-control B. Ecological C. Case-series D. Cross-sectional
B. Ecological
Which of the following study designs should be used to compare disease frequency? A. Case-control B. Ecological C. Case-series D. Cross-sectional
B. Ecological Ecological studies - use data from entire populations (aggregate data) - identify groups by place and time - compare disease frequencies (bw same or diff populations) - describe relative to population-wide factors - often draw associations between occupation, env, and disease - expressed in mean, median, or mode (summary statistics) - measure of association is simple correlation coefficient - focuses on relationship between exposure and outcome
Which of the following health services is considered part of the core function of Assurance? A. Diagnose and investigate health problems and health hazards in the community B. Enforce laws that and regulations that protect and ensure safety C. Monitor health status to identify community health problems D. Inform, educate, and empower people about health issues
B. Enforce laws that and regulations that protect and ensure safety 4 Services of Assurance: - Enforce laws that and regulations that protect and ensure safety - Link people to personal health services and assure the provisions of health care when otherwise unavailable - Assume a competent public health and personal health care workforce - Evaluate effectiveness, accessibility, and quality of personal and population-based health services
Which of the following terms refers to a non-random inaccuracy in measurement or classification in a study that leads to an incorrect estimate of the associate b/w exposure and disease A. Selection bias B. Information bias C. Covariant D. Confounder
B. Information bias A bias is any systematic error (NOT RANDOM) in a study that leads to an incorrect estimate of the association b/w exposure and disease. It can occur in the design, implementation, or analysis of a study. It is the tendency to over or underestimate a parameter intentionally. ______________________ Wrong answers: - Selection bias: variation in how participants are selected (e.g. - sample is non-representative) - Covariant: We dont need to know this term - Confounder: influence of a "3rd variable" in a study that leads to incorrect association between exposure and disease
Which of the following sections in an article notes gaps in knowledge about a subject? A. Abstract B. Introduction C. Methods D. Results E. Discussion
B. Introduction
Which of the following is a main limitation of cohort studies? A. Inability to validate statistical association B. Loss to follow up of subjects C. Inability to detect complicated relationships D. deals only with survivors
B. Loss to follow up of subjects Other limitations of Cohort studies: - large and expensive - long duration of follow-up - inefficient for studying rare diseases - loss to follow-up with subjects - Must anticipate secular trends in technology, behaviors, etc... - Difficulties in measuring confounding variables - Exposures can change through study The quality of the data is not consistent, when compared to other types of studies ___________________________ Wrong answers: A. Inability to validate statistical association - this is a limitation of case sesries/report C. Inability to detect complicated relationship - this is a limitation of ecological studies D. deals only with survivors. - this is a limitation of cross-sectional studies
Chronic neutrophilic leukemia is a rare disease that has affected 200 people to date. If you were to choose to perform a study on these 200 people to test the disease, although you will most likely not do this, which research design would be the best to use? A. cross sectional B. case-control C. case report D. case series E. cohort
B. case-control Case-control studies are best used to test rare diseases.
Which of the following is not an example of a screening test? A. HIV test B. PSA C. CBC D. Fecal Occult blood
C. CBC
Which of the following study designs is best to measure the association of Odds Ratio? A. Case series B. Cohort C. Case control D. Cross-sectional
C. Case control OR = CASE-CONTROL
Which of the following is not a descriptive observational study design? A. Case series B. Ecological study C. Case-control D. Cross sectional
C. Case-control Types of Study Designs: Observational: Descriptive - Case reports/series - Ecological Studies - Cross-sectional Analytic - Case-Control - Cohort Experimental: - RCT - Other (before&after, non-randomized)
In which study design would you select participants based on exposure status? A. Case series B. Case-control C. Cohort D. Cross-sectional
C. Cohort
Which of the following observational studies looks both forward and backward? A. Case series B. Case-control C. Cohort D. Cross-sectional
C. Cohort Because retrospective and prospective
Which of the following study designs is one that two or more groups of people that are free of disease and differ in exposure are compared with respect to INCIDENCE? A. Case series B. Case-control C. Cohort D. Cross-sectional
C. Cohort Cohort studies can be retrospective or prospective. Prospective - start with exposed and unexposed groups and follow them for years Retrospective - look back to find group of exposed and unexposed and "follow" them to the present
Which of the following questions does the PPV answer? A. How many people have the disease and test negative? B. How many people that tested positive actually have the disease? C. How likely is it that the patient has the disease given that the test result is positive? D. How likely is it that the patient does not have the disease given that the test result is negative?
C. How likely is it that the patient has the disease given that the test result is positive? The positive predictive value is the PROBABILITY that a person who receives a positive screening will actually have the disease. It is not quantifying how many people have a disease. Example: A positive Pap smear - Since the person tested positive for an abnormal Pap, a PPV will tell what the likelihood a person will have cervical cancer.
Which of the following health services is considered part of the core function of Assessment? A. Mobilizing community partnerships to identify and solve health problems B. Enforce laws that and regulations that protect and ensure safety C. Monitor health status to identify community health problems D. Evaluate effectiveness, accessibility, and quality of personal and population-based health services
C. Monitor health status to identify community health problems 2 Services of Assessment: - Monitor health status to identify community health problems - Diagnose and investigate health problems and health hazards in the community _________________________________ Wrong answers: A. Mobilizing community partnerships to identify and solve health problems - Policy Development B. Enforce laws that and regulations that protect and ensure safety - Assurance D. Evaluate effectiveness, accessibility, and quality of personal and population-based health services - Assurance
Which of the following is not an example of a health indicator? A. Access to health services B. Oral health C. Personality D. Environmental quality E. Substance abuse
C. Personality Health indicators are characteristics of a population that can be quantified to to describe the influence on health status of that population. Examples are: - Health care access - Mental health - Clinical preventative services - Env. quality - Injury and violence - Maternal, infant, child health - Nutrition, physical activity, and obesity - Oral health - Reproductive and sexual health - Social determinants - Substance abuse - Tobacco
Which of the following is not a strength of ecological studies? A. surveillance data allows comparison of info from different geographical areas B. Quick and cheap C. Provides info on individual-participant values D. analysis and explanation are easy to understand
C. Provides info on individual-participant values One of the limitations of ecological studies is that it does not have information on individual values
Which of the following methods of prevention works to minimize disability through rehabilitation services? A. Primary Prevention B. Secondary Prevention C. Tertiary Prevention D. Quaternary Prevention
C. Tertiary Prevention 3 Levels of Prevention - Primary: preventing disease/injury from occurring - Secondary: minimizes severity of illness/injury once it has already occurred - Tertiary: Minimizes disability through medical care or rehab services
Which of the following would pose an issue to establishing a screening program with regard to the test itself? A. Is it acceptable to the people at risk B. Has adequate sensitivity, specificity, PPV, and NPV C. The test is expensive D. It is standardized
C. The test is expensive If the test is expensive, it may make the establishment of a screening program difficult Things to keep in mind about the test: - It's acceptable to those at risk of disease - Has adequate sensitivity, specificity, and predictive values - It is available at reasonable cost - it is standardized to be performed consistently, accurately, and reproducibility
Which of the following would result in a test with a lot of false positives? A. high sensitivity, high specificity B. low sensitivity, low specificity C. high sensitivity, low specificity D. low sensitivity, high specificity
C. high sensitivity, low specificity
What are 3 limitations to a case report study ?
Case reports are detailed accounts of a patient by 1 or more clinicians 1. Cant be used to test for the presence of a valid statistical association 2. It's only based on one person's experience 3. Any risk factors may be coincidental
What is a health indicator?
Characteristics of a population that can be quantified (via scientific research) to describe influence on health status of that population
T or F: Most epidemiologic studies are experimental.
False. Most epidemiologic studies are observational. Exposed and unexposed groups exist before the epidemiologist arrives on the scene.
Which of the following Odds Ratio values indicate that the odds a new disease is greater in exposed than unexposed groups during a specific period of time? A. 0 B. 0.5 C. 1 D. 2
D. 2 If an Odds Ratio is > 1, then it shows that there is a DIRECT relationship between the number of people being exposed to a disease and the outcome ______________________ Wrong answers: 0 and 0.5 are both < 1, so this means that there is an INVERSE or protective relationship between the exposure and the outcome If an OR value = 1, this means that there is NO relationship between the exposure and outcome ______________________
Which of the following is not a quality of a good screening test? A. Acceptability B. Applicability C. Reliability D. Assurance E. Validity
D. Assurance Assurance is 1 of the 3 Core Functions of Public Health. The others are: Assessment Policy Development ____________________ 4 Qualities of a Good Screening Test: - Reliability: How consistent the test is over repeated tests - Applicability: How well a test can be applied/administered to the target population - Acceptability: How well the population accepts the test based on safety, comfort, pros and cons, and how invasive the test it - Validity: Similar to accuracy. Can be tested by sensitivity and specificity
Which of the following study designs is the following information an example of? 5 young, previously healthy homosexual men diagnosed with Pneumocystis carinii pneumonia (PCP) at three LA hospitals during a 6-month period in 1980-1981 A. Cross-sectional B. Retrospective cohort C. Case control D. Case series
D. Case series This information is based on a case-series study because it is a collection of individual case reports in a short time window. It may be used to identify the beginning or presence of an epidemic Limitations of Case-Series: - cant be used to validate statistical association - there is not appropriate comparison group so it's hard to interpret - this previous lack can obscure a relationship or suggest association when there isn't
Which of the following tests will result in categorical outcomes? A. One-Way ANOVA B. Independent T-Test C. Multiple Linear Regression D. Chi-squared
D. Chi-squared Only 2 of the 9 tests will yield Categorical/Dichotomous data: - Chi-squared - Multiple Logistic Regression Analysis
Which of the following observational studies looks at simultaneous events? A. Quasi-Experimental B. Case-control C. Cohort D. Cross-sectional
D. Cross-sectional Think of the U.S. Census
Which of the following questions does the NPV answer? A. How many people have the disease and test negative? B. How many people that tested positive actually have the disease? C. How likely is it that the patient has the disease given that the test result is positive? D. How likely is it that the patient doesn't have the disease given that the test result is negative?
D. How likely is it that the patient doesn't have the disease given that the test result is negative? The NPV test how likely (probability) that a person is, indeed, disease-free if they test negative. Example: - Negative Pap smear: an NPV will tell that likelihood that a person does not have cervical cancer.
Which of the following health services is considered part of the core function of Policy Development? A. Diagnose and investigate health problems and health hazards in the community B. Enforce laws that and regulations that protect and ensure safety C. Monitor health status to identify community health problems D. Inform, educate, and empower people about health issues
D. Inform, educate, and empower people about health issues 3 Services of Assessment: - Inform, educate, and empower people about health issues - Mobilizing community partnerships to identify and solve health problems - Develop policies and plans that support individual and community health efforts
Which of the following is an analytic study design? A. Ecological study B. Cross-sectional C. Randomized controlled trials D. Prospective Cohort E. Case reports
D. Prospective Cohort Types of Study Designs: Observational: Descriptive - Case reports/series - Ecological Studies - Cross-sectional Analytic - Case-Control - Cohort Experimental: - RCT - Other (before&after, non-randomized)
Which of the following would not pose an issue to establishing a screening program with regard to the disease itself? A. causes low morbidity/mortality B. responds only to very specific treatments/interventions C. unidentifiable until after symptoms arise D. is prevalent in the population getting screened
D. is prevalent in the population getting screened Things that need to be considered in establishing a screening program regarding disease: - It should cause significant morbidity/mortality - Should be identifiable at pre-symptomatic phase before an individual would seek out care - Treatment/intervention of disease should be available, effective, and acceptable - Disease should be prevalent in the population you're testing for
Which of the following is not a source of data in public health? A. Death records B. U.S. Census C. EPA government survey D. Divorces E. All of the above
E. All of the above 3 main sources of data in public health: - vital statistics - u.s. census - National Surveys Vital statistics includes: (info should be collected by states) - birth and death records - marriages - divorces - spontaneous fetal deaths - abortions U.S. Census: (most accurate) - collected every 10 years - serves as denominator for most public health data - mandated by US. constitution - American Community Survey is done between censuses National Surveys: - can be done country-wide or state-to-state (Behavioral Risk Factor Surveys)
Which of the following study designs is considered the most scientifically rigorous method of hypothesis testing available in epidemiology? A. Quasi-experimental B. Case-control C. Cohort D. Cross-sectional E. Randomized Controlled Trial
E. Randomized Controlled Trial 3 Objectives of Randomized trials: To Evaluate - 1. Therapeutic and preventative aspects of medical practice 2. New approaches in health care delivery 3. impact of health education on health behavior
What is an ecological fallacy?
Ecological fallacy is the idea that although there is an association between variables in the population that you test, this association may not exist at the individual level. E.g. - a class in a school scored the highest in the district. This does not mean that a specific child in the class (anyone chosen at random) is a math genius. They are just high overall in the district, but the district may be incredibly low in math skills. E.g. - A study that includes people with eyeglasses showed that they have above-average intelligence. You wear glasses, so you must be intelligent. I am not, sadly.
Which of the following is not included in the Public Health Approach is health issues? A. Develop and test community-level interventions to control or prevent the problem B. Define the health problem C. Implement the interventions to improve the population's health D. Identify the risk factors involved in the problem E. Monitor interventions to assess their effectiveness F. They are all included
F. They are all included Public Health Approach: - Define the problem - Identify risk factors - Develop community-level tests/interventions - Implement interventions - Monitor effectiveness
True or false: All systematic reviews are meta-analyses but not all meta-analyses are systematic reviews
FALSE. ALL META-ANALYSES ARE SYSTEMATIC REVIEWS, BUT NOT ALL SYSTEMATIC REVIEWS ARE META-ANALYSES meta-analyses = systematic review systematic review doesnt always = meta-analys
True or False: A focus group would be a great way to collect data for a quantitative study.
False. A focus group would be good for collecting qualitative data. Focus groups are useful for getting opinions on things, which is something that is collected in a qualitative study. Qualitative studies try to get explore issues in-depth. Other methods for collecting qualitative data are: - participant observations - passive observation - field notes - receptive listening - reflexive journals - in-depth interviews - focus groups - analysis of documents
T or F: Correlational studies test causality between exposure and disease.
False. Correlational studies are used to generate hypotheses. They do NOT test causality.
T or F: The difference between RCT and Quasi-Experimental studies = double blind vs single blind
False. Difference bw RCT and Quasi = RANDOMIZATION
True or False: Difference btw case-control & retrospective cohort is that in case-control, you know the exposure but not the disease, and the retrospective cohort is the opposite.
False. In a retrospective cohort you know the exposure, but not the disease. In case-control, you know the disease, but not the exposure.
