Health, Medicine, and Social Epidemiology (9A) - Psych & Soc

What is a protective factor in social epidemiology?

Characteristic associated with decreased probability of disease. Exposure that lowers disease risk below baseline.
What is the social gradient in health as described by social epidemiology?

Health improves stepwise as socioeconomic status increases. Not just poor vs rich; each SES level shows better health.
What is the ecological fallacy?

Inferring individual-level relationships from group-level (aggregate) data. Population patterns may not apply to individuals within groups.
What is selection bias in medical or epidemiologic studies?

Systematic differences in who is selected into the study. Non-random sampling affects study generalizability.
What is the definition of a cohort study design?

Follows exposed and unexposed groups forward to compare outcomes. Prospective design tracks disease development over time.
State the formula for point prevalence using cases and population size.

$\text{Prevalence} = \frac{\text{existing cases}}{\text{total population}}$ . Proportion of population with disease at one time point.
What is recall bias in epidemiologic research?

Differential accuracy of remembered past exposures between groups. Cases may remember exposures better than controls.
State the formula for specificity using true negatives (TN) and false positives (FP).

$\text{Specificity} = \frac{\text{TN}}{\text{TN} + \text{FP}}$ . Proportion of healthy correctly identified as negative.
What is a confounder (confounding variable) in epidemiologic research?

A third variable related to both exposure and outcome. Can falsely create or hide true associations if not controlled.
What is the definition of a confounder in an observational study?

Third variable related to exposure and outcome that distorts association. Confounders create spurious associations, requiring statistical adjustment to isolate true exposure-outcome relationships.
What is the difference between a risk factor and a protective factor?

Risk increases disease likelihood; protective decreases it. Factors modify disease probability in opposite directions.
Which study design follows a disease-free group forward in time to measure incidence?

Cohort study. Prospective design allows direct incidence calculation.
Identify the term for immunity gained when enough people are immune to reduce spread.

Herd immunity. Protects vulnerable individuals who cannot be vaccinated.
State the formula for prevalence in terms of incidence and duration.

$ \text{Prevalence} \approx \text{Incidence} \times \text{Average duration}$. Shows how new cases accumulate over disease duration.
Which level of prevention emphasizes screening and early detection to reduce severity?

Secondary prevention. Secondary prevention detects asymptomatic or early-stage disease through methods like mammography to improve prognosis.
State the formula for prevalence.

$\text{Prevalence} = \frac{\text{existing cases}}{\text{total population}}$ . Point or period measure; affected by both incidence and duration.
State the formula for risk (cumulative incidence) over a time interval.

$\text{Risk} = \frac{\text{new cases}}{\text{population at risk}}$ . Assumes closed cohort; gives proportion who develop disease.
What is the definition of a health disparity?

Systematic health differences linked to social disadvantage. Health disparities arise from inequities in access, resources, and opportunities, perpetuating unequal health outcomes.
What is the definition of a protective factor in social epidemiology?

Characteristic associated with decreased probability of disease. Reduces disease risk through various mechanisms.
What is the definition of social determinants of health (SDOH)?

Social and environmental conditions shaping health risks and outcomes. SDOH influence health through factors like education, income, and housing, beyond individual behaviors or genetics.
State the formula for cumulative incidence (risk) over a time interval.

$\text{Incidence}=\frac{\text{new cases}}{\text{population at risk}}$ . Cumulative incidence estimates the probability of developing the disease during a specified period among those at risk.
What is the definition of selection bias in a study sample?

Systematic differences from nonrandom participant selection. Occurs when study sample differs from target population.
What is the definition of specificity for a diagnostic test?

Probability the test is negative given disease is absent. High specificity minimizes false positives.
Identify the interpretation of $RR=1$ for an exposure-outcome relationship.

No association between exposure and outcome. Equal risk in both groups indicates no effect.
Identify the type of prevention: A vaccine given before any symptoms occur.

Primary prevention. Prevents disease before it occurs.
What is the definition of epidemiology in the context of population health?

Study of disease distribution and determinants in populations. Focuses on patterns and causes across groups, not individuals.
Which option best interprets $OR = 1.0$ ?

No association between exposure and outcome. Equal odds indicate exposure doesn't affect outcome likelihood.
What is the difference between communicable and noncommunicable diseases?

Communicable are infectious; noncommunicable are not. Transmission potential distinguishes disease categories.
Which level of prevention aims to prevent disease onset (before it occurs)?

Primary prevention. Primary prevention targets root causes like vaccination or lifestyle changes to avoid disease development entirely.
Which design is most efficient for rare diseases: cohort or case-control?

Case-control study. Starts with rare disease cases, then finds controls.
State the formula for case fatality rate (CFR).

$\text{CFR}=\frac{\text{deaths from disease}}{\text{diagnosed cases}}$ . Often expressed as percentage; higher means deadlier disease.
Which option best interprets $RR = 2.0$ ?

Exposed group has twice the risk of the outcome vs unexposed. Risk doubles with exposure compared to without.
What is specificity in the context of a diagnostic test?

Probability a test is negative given disease is absent. True negative rate; correctly identifies healthy individuals.
Identify the interpretation of $RR = 1$ for an exposure-outcome relationship.

No association between exposure and outcome. Equal risks mean exposure doesn't affect outcome.
State the formula for odds ratio (OR) using odds in exposed and unexposed groups.

$OR=\frac{\text{odds in exposed}}{\text{odds in unexposed}}$ . Approximates RR when disease is rare.
What does the term health disparity mean in social epidemiology?

Systematic health differences linked to social disadvantage. Often tied to socioeconomic status, race, or geography.
State the formula for sensitivity using true positives (TP) and false negatives (FN).

$\text{Sensitivity} = \frac{\text{TP}}{\text{TP} + \text{FN}}$ . Proportion of diseased correctly identified as positive.
Identify the study design that measures exposure and outcome at the same time point.

Cross-sectional study. Provides prevalence data; cannot establish temporal sequence.
What is the definition of relative risk (RR) in epidemiology?

Risk in exposed group divided by risk in unexposed group. Compares disease rates between exposed and unexposed.
Which measure is most sensitive to disease duration: incidence or prevalence?

Prevalence. Longer disease duration increases existing cases.
What is a randomized controlled trial (RCT) in clinical epidemiology?

Experiment with random assignment to intervention vs control. Gold standard for causal inference; minimizes confounding.
What is the definition of life expectancy in population health?

Average number of years a person is expected to live. Statistical estimate based on current mortality rates.
What is the odds ratio, and which study design most directly estimates it?

OR compares odds; classically estimated in case-control studies. Approximates RR when disease is rare; retrospective design.
What is the placebo effect in medical research?

Symptom change due to treatment expectations. Psychological response, not pharmacological effect.
What study design starts with diseased and non-diseased groups and looks back for exposures?

Case-control study. Retrospective design efficient for rare diseases.
Identify the type of prevention: Physical therapy after a stroke to reduce disability.

Tertiary prevention. Manages existing disease to prevent complications.
What is the definition of incidence in epidemiology?

New cases in a population during a specified time period. Measures disease occurrence rate, not total cases.
Which measure is most sensitive to changes in disease duration: incidence or prevalence?

Prevalence. Longer disease duration increases prevalence but not incidence.
Which measure is most useful for identifying risk of developing disease: incidence or prevalence?

Incidence. New cases indicate likelihood of getting disease.
What is the fundamental attribution error as it relates to health outcomes?

Overattributing health outcomes to individual traits while underweighting context. Ignores social determinants by focusing on personal responsibility.
What is the formula for odds ratio (OR) using a $2\times^2$ table cells $a,b,c,d$ ?

$OR=\frac{ad}{bc}$ . Cross-product ratio from contingency table.
What is the definition of specificity for a diagnostic test?

Probability test is negative given disease is absent. True negative rate; ability to rule out disease.
What is the definition of a social determinant of health?

Nonmedical social conditions that influence health outcomes. Include income, education, housing, environment.
Which measure is typically higher for chronic diseases: incidence or prevalence?

Prevalence. Chronic diseases accumulate cases over time.
What is the prevalence of a disease?

Total existing cases in a population at a given time. Snapshot of disease burden; includes both new and old cases.
What is the definition of morbidity in public health?

Illness or disease burden in a population. Includes both physical and mental health conditions.
What is the formula for incidence proportion (cumulative incidence) over a time interval?

$\text{Incidence proportion} = \frac{\text{new cases}}{\text{population at risk}}$ . Risk of developing disease during the time period.
Identify the study design that starts with disease status and looks back for prior exposures.

Case-control study. Works backward from cases/controls to compare past exposures.
What is mortality?

Death rate in a population. Specifically measures deaths, not illness.
What is recall bias, and in which design is it most common?

Differential memory of exposure; common in case-control studies. Cases remember exposures better than controls.
State the formula for incidence proportion (cumulative incidence).

$\text{Incidence proportion}=\frac{\text{new cases}}{\text{population at risk}}$ . Measures new disease occurrence in at-risk population.
State the formula for point prevalence using cases and population size.

$\text{Prevalence} = \frac{\text{existing cases}}{\text{total population}}$ . Proportion of population with disease at one time point.
What does it imply if relative risk equals $1$ for exposure and disease?

No association between exposure and outcome. Equal risk in both groups; exposure doesn't affect outcome.
Which study design is most efficient for rare diseases: cohort or case-control?

Case-control. Easier to find enough rare disease cases to compare.
What is the definition of a confounder?

A third variable related to both exposure and outcome. Can create false associations if not controlled.
What is the definition of morbidity in public health contexts?

Illness or disease burden in a population. Measures sickness, not death, in populations.
What is the definition of social determinants of health (SDOH)?

Social and economic conditions shaping health risks and outcomes. Include education, income, housing, and neighborhood factors.
What is the definition of a case-control study design?

Starts with cases and controls, then compares prior exposures. Retrospective design looks backward from disease status.
Identify whether causation is supported: $RR=1.0$ for exposure and disease.

No association (neither increased nor decreased risk). RR=1 means equal risk in both groups.
What is the definition of a health disparity in social epidemiology?

Systematic health differences across socially advantaged vs disadvantaged groups. Avoidable, unfair health differences between groups.
Which option best defines the social gradient in health outcomes?

Health improves as socioeconomic status increases. Linear relationship between social position and health.
What is the main feature that distinguishes a cross-sectional study design?

Exposure and outcome are measured at the same time point. Snapshot approach captures both simultaneously.
What is recall bias, and which study type is it most associated with?

Differential memory of exposure; most common in case-control. Cases may remember exposures better than controls.
What is the definition of infant mortality rate (IMR)?

Deaths before age 1 per live births in a given year. IMR, typically per 1,000 live births, reflects child health and socioeconomic conditions in a population.
What is the definition of a pandemic in epidemiology?

An epidemic spread across multiple countries or continents. Global scale distinguishes from epidemic.
What is the health belief model concept of perceived barriers?

Beliefs about obstacles or costs that reduce likelihood of action. High perceived barriers decrease preventive health behaviors.
What is the definition of prevalence in epidemiology?

Total number of cases in a population at a given time. Includes both new and existing cases (point prevalence).
Which measure is most useful for estimating disease burden: incidence or prevalence?

Prevalence. Total cases reflect overall disease impact on resources.
What is epidemiology in the context of population health and disease prevention?

Study of disease distribution and determinants in populations. Focuses on patterns and causes at the population level, not individuals.
State the formula for sensitivity using a $2\times^2$ table.

$\text{sensitivity}=\frac{TP}{TP+FN}$ . True positives divided by all with disease.
What is the definition of risk factor in epidemiology?

Exposure associated with increased probability of disease. Can be modifiable (smoking) or non-modifiable (age).
What is the definition of morbidity?

Illness or disability in a population. Encompasses all non-fatal health conditions.
What is the definition of a randomized controlled trial (RCT)?

Experimental study with random assignment to intervention vs control. Randomization minimizes confounding bias.
What is a risk factor in epidemiology?

An exposure associated with increased probability of an outcome. Increases disease risk when present.
State the formula for sensitivity using $TP$ and $FN$ .

$\text{Sensitivity}=\frac{TP}{TP+FN}$ . True positives divided by all who have disease.
Which measure is generally most useful for studying rare diseases: incidence or prevalence?

Incidence. New cases easier to identify when disease is uncommon.
What is the definition of prevalence (point or period) in epidemiology?

Total existing cases in a population at a time (or interval). Captures disease burden regardless of when cases began.
State the formula for specificity using $TN$ and $FP$ .

$\text{Specificity}=\frac{TN}{TN+FP}$ . True negatives divided by all who don't have disease.
What is the difference between correlation and causation in health research?

Correlation is association; causation means one variable produces change. Causation requires direct effect, not just statistical relationship.
Identify the correct level of prevention: vaccines given before disease onset.

Primary prevention. Prevents disease occurrence in healthy populations.
State the formula for incidence proportion (cumulative incidence).

$\text{Incidence proportion} = \frac{\text{new cases}}{\text{population at risk}}$ . Measures risk of developing disease over time period.
What is the definition of sensitivity for a diagnostic test?

Probability test is positive given disease is present. True positive rate; ability to detect disease.
State the formula for relative risk using event rates in exposed and unexposed groups.

$RR = \frac{\text{risk}_{\text{exposed}}}{\text{risk}_{\text{unexposed}}}$ . Direct comparison of disease probabilities by exposure.
What is a risk factor in social epidemiology?

A characteristic associated with increased disease probability. Identifies factors that increase disease risk but may not cause it.
Which measure is most useful for assessing the burden of chronic disease: incidence or prevalence?

Prevalence. Chronic diseases persist over time, making prevalence a better indicator of ongoing impact than incidence, which tracks new cases.
What is the definition of a cohort study?

Observational study following exposed vs unexposed over time. Prospectively tracks disease development.
What is the key feature that distinguishes a case-control study design?

Groups are defined by outcome; prior exposures are compared. Retrospective design: outcome already occurred.
What is the definition of morbidity (as used in public health)?

Illness or disease burden in a population. Encompasses all non-fatal health conditions.
State the formula for incidence proportion (cumulative incidence) over a period.

$\text{Incidence proportion}=\frac{\text{new cases}}{\text{population at risk}}$ . Risk of developing disease during the study period.
What is a risk factor in social epidemiology?

Characteristic associated with increased probability of disease. Exposure that raises disease risk above baseline.
What term describes a person's evaluation of their own health status?

Self-rated (self-reported) health. Subjective assessment that predicts actual health outcomes.
State the formula for case fatality rate (CFR).

$\text{CFR}=\frac{\text{deaths from disease}}{\text{diagnosed cases}}$ . CFR quantifies the severity of a disease by dividing fatalities by confirmed cases, often expressed as a percentage.
What is the definition of case fatality rate (CFR)?

Proportion of diagnosed cases that die from the disease. Measures disease severity and treatment effectiveness.
What is the definition of social determinants of health (SDOH)?

Social conditions shaping health risks and outcomes. Include income, education, housing, and environment.
Identify the study design that compares disease rates between exposed and unexposed groups over time.

Cohort study. Cohort studies prospectively or retrospectively follow groups to assess exposure effects on outcomes, enabling risk calculation.
What is the definition of a protective factor in epidemiology?

A characteristic associated with reduced probability of disease. Exposure decreases disease likelihood.
Which measure is typically higher for chronic diseases with long duration: incidence or prevalence?

Prevalence. Long-lasting diseases accumulate cases over time.
What is the definition of morbidity as used in public health?

Illness or disease burden in a population. Encompasses all health conditions, not just death.
What is the main feature that distinguishes a case-control study design?

Participants are grouped by disease status and prior exposure is assessed. Retrospective design looks backward from outcome.
Identify the study design that starts with exposure and follows participants forward to outcome.

Cohort study. Prospective design; can directly calculate incidence and RR.
What is the definition of mortality rate in epidemiology?

Deaths in a population during a specified time period. Death rate per population unit over time.
What is the fundamental cause theory of health disparities?

SES drives disparities by shaping access to flexible resources. Resources like money and knowledge persistently advantage health.
What is the biomedical model of health and illness?

Illness as biological dysfunction; mind and social factors minimized. Focuses solely on physical causes, ignoring psychological and social factors.
What is selection bias in a study?

Systematic differences from how participants are chosen or retained. Non-random sampling distorts study results.
What is the definition of an epidemic in epidemiology?

Rapid increase in cases above expected levels in a region. Wider geographic spread than an outbreak.
What is a social determinant of health?

A social condition shaping health (e.g., income, housing). Non-medical factors influencing population health outcomes.
What is the definition of epidemiology in public health?

Study of disease distribution and determinants in populations. Epidemiology focuses on patterns, causes, and effects of health conditions to inform public health strategies and interventions.
Identify the interpretation of $RR<1$ for an exposure-outcome relationship.

Exposure is protective (associated with decreased risk). Exposed group has lower disease risk than unexposed.
Identify the correct level of prevention: rehabilitation to reduce disability after disease.

Tertiary prevention. Manages existing disease to prevent complications.
Which term refers to an epidemic that occurs across multiple countries or continents?

Pandemic. Widespread epidemic affecting global populations.
What is the definition of confounding in an epidemiologic study?

A third variable distorts the exposure–outcome association. Must be associated with both exposure and outcome.
What does a longer average disease duration do to prevalence, holding incidence constant?

It increases prevalence. Longer duration means cases accumulate, elevating the proportion of affected individuals without changing new case rates.
State the formula for prevalence using cases and population size.

$\text{prevalence}=\frac{\text{existing cases}}{\text{population}}$ . Proportion of population with disease at one time point.
What is morbidity?

Illness or disease in a population. Morbidity encompasses non-fatal health outcomes, used to evaluate disease impact beyond mortality.
What is social epidemiology as a field of study?

Study of how social conditions shape population health and disease. Examines how social factors (income, education) affect health patterns.
What is the formula for positive predictive value (PPV) in terms of test results?

$\text{PPV}=\frac{TP}{TP+FP}$ . Probability that a positive test correctly identifies disease.
What is the difference between incidence and prevalence?

Incidence = new cases; prevalence = all existing cases at a time. Incidence measures new occurrences; prevalence counts total burden.
What is the biomedical model of health in medical sociology?

Health as absence of disease; focuses on biological pathology and treatment. Views health mechanistically, ignoring psychosocial influences.
What is mortality in epidemiology?

Death rate or frequency of death in a population. Measures deaths, distinct from disease occurrence (morbidity).
What is the definition of incidence in epidemiology?

New cases in a population during a specified time period. Measures new disease occurrence, not total cases.
What is a protective factor in epidemiology?

Exposure or characteristic associated with decreased disease likelihood. Reduces disease risk through beneficial exposures or behaviors.
What is the definition of health disparity in social epidemiology?

A preventable difference in health linked to social disadvantage. Inequities that could be eliminated through policy or intervention.
Identify the bias when exposure measurement differs systematically between cases and controls.

Recall bias. Cases remember exposures differently than controls do.
What is the formula for relative risk (RR) in terms of incidence?

$RR=\frac{I_{exposed}}{I_{unexposed}}$ . Compares disease incidence between groups.
What is the operational definition of a risk factor in epidemiology?

Exposure associated with increased probability of a health outcome. Statistical association, not necessarily causal.
What is relative risk (risk ratio) in a cohort study?

$\text{RR} = \frac{\text{risk in exposed}}{\text{risk in unexposed}}$ . Values >1 indicate increased risk with exposure.
Which measure is most appropriate for studying rare diseases: incidence or prevalence?

Incidence. New cases are easier to detect than total cases in rare diseases.
State the formula for prevalence in a population at a given time.

$\text{Prevalence} = \frac{\text{existing cases}}{\text{total population}}$ . Proportion of population with condition at specific time point.
State the formula for incidence proportion (cumulative incidence).

$\text{Incidence proportion}=\frac{\text{new cases}}{\text{population at risk}}$ . Excludes those already with disease from denominator.
What term describes the unequal distribution of health outcomes across social groups?

Health disparities (health inequities). Systematic differences in health between population groups.
State the formula for relative risk (RR) using risk in exposed and unexposed groups.

$RR=\frac{\text{risk in exposed}}{\text{risk in unexposed}}$ . Compares disease risk between exposed and unexposed.
What is the definition of the nocebo effect?

Worsened symptoms due to negative expectations about a treatment. Opposite of placebo; expectations cause harm.
Identify the study design that follows a disease-free group forward to compare incidence by exposure.

Cohort study (prospective if exposure is assessed before outcome). Tracks groups over time to compare disease development.
State the formula for odds ratio using a $2\times 2$ table with cells $a,b,c,d$ .

$\text{OR} = \frac{ad}{bc}$ . Cross-product ratio from contingency table.
What is the defining feature of a randomized controlled trial (RCT)?

Random assignment to treatment versus control. Randomization minimizes selection bias and confounding.
Identify the type of prevention: Mammography used to detect breast cancer early.

Secondary prevention. Detects disease early when treatment is most effective.
What is the definition of iatrogenic illness?

Illness caused by medical examination or treatment. Healthcare itself becomes the cause of illness.
What is the definition of mortality rate in a population?

Deaths in a population per unit time. Mortality rate indicates the frequency of deaths, often standardized per 1,000 people, to compare population health risks.
Identify the bias when the study sample is not representative due to how participants are recruited or retained.

Selection bias. Non-random sampling creates systematic differences between groups.
What is social epidemiology?

Study of how social structures and contexts shape disease distribution. Examines how social factors create patterns of illness.
Which term describes differences in health outcomes that are avoidable and unjust?

Health inequities. Result from unfair social conditions, not biology alone.
Which study design measures exposure and outcome at a single time point?

Cross-sectional study. Provides snapshot prevalence but can't establish causation.
What is the definition of a confounder in an epidemiologic study?

Third variable related to exposure and outcome that biases association. Must be associated with both to distort true relationship.
State the formula for relative risk using incidence in exposed and unexposed groups.

$\text{RR} = \frac{I_{\text{exposed}}}{I_{\text{unexposed}}}$ . Compares disease risk between exposed and unexposed.
What is the difference between health disparities and health care disparities?

Health disparities = outcomes; health care disparities = access/quality differences. Outcomes reflect disease burden; care reflects system inequities.
What is the difference between incidence and prevalence?

Incidence = new cases; prevalence = existing cases at a time. Incidence measures new occurrences; prevalence counts all current cases.
Identify the interpretation of $RR>1$ for an exposure-outcome relationship.

Exposure is associated with increased risk (risk factor). Exposed group has higher disease risk than unexposed.
What is recall bias in a case-control study?

Differential accuracy of past exposure reporting by cases versus controls. Cases may remember exposures differently than controls, biasing results.
What is the key difference between a cohort study and a case-control study?

Cohort: start with exposure; case-control: start with outcome. Direction of investigation differs: forward vs backward in time.
State the formula for odds ratio using a $2\times^2$ table with cells $a,b,c,d$ .

$OR = \frac{ad}{bc}$ . Cross-product ratio from $2\times^2$ contingency table.
Which statement best defines health disparities in social epidemiology?

Systematic, avoidable health differences linked to social disadvantage. Emphasizes inequity, not just difference.
What is morbidity (as used in epidemiology)?

Disease or disability within a population. Refers to the burden of illness, not death, in a population.
What is the difference between a placebo effect and the nocebo effect?

Placebo improves; nocebo worsens due to expectations. Both are expectation-driven effects with opposite health impacts.
Identify the study design that starts with cases and controls and looks back for prior exposure.

Case-control study. Compares past exposures between diseased and healthy groups.
What is the definition of prevalence in epidemiology?

Total existing cases in a population at a given time. Includes both new and old cases at a specific point.
What is the difference between an epidemic and a pandemic?

Epidemic: regional surge; pandemic: global spread across countries/continents. Scale differentiates local outbreaks from worldwide spread.
What is selection bias in a study, stated in one sentence?

Systematic differences in who is included that distort results. Non-random sampling or loss to follow-up creates bias.
State the formula for positive predictive value (PPV) using $TP$ and $FP$ .

$\text{PPV}=\frac{TP}{TP+FP}$ . True positives divided by all positive tests.
What is the definition of a case-control study?

Observational study comparing prior exposures in cases vs controls. Retrospectively examines past exposures.
What is the difference between incidence and prevalence?

Incidence = new cases; prevalence = existing cases. Incidence measures disease onset; prevalence measures current burden.
Which level of prevention focuses on rehabilitation and limiting complications of established disease?

Tertiary prevention. Tertiary prevention manages chronic conditions to prevent worsening, such as through therapy or support groups.
Calculate relative risk: $I_{\text{exposed}}=0.20$ and $I_{\text{unexposed}}=0.05$ .

$\text{RR} = 4$ . $\frac{0.20}{0.05} = 4$ times higher risk in exposed group.
Which term refers to the occurrence of disease outbreaks above expected levels in a region?

Epidemic. Localized increase in disease cases beyond normal expectations.
What is morbidity in epidemiology?

Illness or disease burden in a population. Measures disease frequency, not deaths.
What is the difference between an epidemic and a pandemic?

Epidemic is regional increase; pandemic is global spread. Geographic scope distinguishes the two terms.
What is the biopsychosocial model of health and illness?

Health reflects biological, psychological, and social influences. Integrates all three domains for comprehensive understanding of health.
What is the definition of social determinants of health (SDOH)?

Social and environmental conditions shaping health risks and outcomes. Includes income, education, housing, and neighborhood factors.
What type of measure is typically calculated in a case-control study?

Odds ratio. Case-control studies can't directly measure risk, only odds.
What is the definition of an epidemic disease pattern?

Sudden increase in cases above expected levels in a region. Epidemics signal a deviation from normal patterns, requiring rapid public health responses to control spread.
State the formula for incidence rate (incidence density).

$\text{Incidence rate} = \frac{\text{new cases}}{\text{person-time at risk}}$ . Accounts for varying follow-up times; denominator is person-years.
What is morbidity?

Illness, disease, or level of poor health in a population. Encompasses all forms of ill health, not just death.
What is the definition of prevalence in epidemiology?

All existing cases in a population at a given time (or period). Includes both new and old cases, unlike incidence.
What is the definition of incidence in epidemiology?

Number of new cases in a population over a time period. Incidence measures the rate at which new instances of a disease occur, aiding in understanding disease dynamics and risk.
What does a positive predictive value (PPV) represent for a diagnostic test?

Probability a person has disease given a positive test result. Depends on test accuracy and disease prevalence in population.
What is the definition of a risk factor in social epidemiology?

Characteristic associated with increased probability of disease. Not causative but statistically linked to disease occurrence.
In a case-control study, which association measure is typically computed instead of $RR$ ?

Odds ratio (OR). Can't calculate incidence from retrospective case-control data.
What is recall bias, and in which study type is it most classically problematic?

Differential memory of exposure; classically in case-control studies. Cases remember exposures better than controls.
What is the definition of mortality rate in epidemiology?

Frequency of deaths in a population during a specified time. Death rate per population unit over time.
Identify the study design that compares disease rates by exposure status going forward in time.

Cohort study. Follows exposed/unexposed groups prospectively for outcomes.
What is prevalence in epidemiology?

Total number of existing cases in a population at a given time. Captures disease burden regardless of when cases began.
State the formula for point prevalence using cases and population size.

$\text{Prevalence}=\frac{\text{existing cases}}{\text{population}}$ . Point prevalence calculates the fraction of the population with the condition at a single time, useful for resource allocation.
What is the biopsychosocial model of health and illness?

Health arises from biological, psychological, and social factors. Integrates three domains rather than focusing on biology alone.
State the formula for relative risk (risk ratio).

$RR = \frac{\text{risk in exposed}}{\text{risk in unexposed}}$ . Compares disease probability between exposed and unexposed groups.
What is the biomedical model of health?

Health as absence of disease; focuses on biological pathology and treatment. Views illness purely through physical/chemical dysfunction.
What is the definition of incidence (as used in epidemiology)?

Number of new cases in a population over a time period. Measures disease onset rate, not total burden.
What is the main feature that distinguishes a cohort study design?

Participants are grouped by exposure and followed for outcomes. Prospective design tracks exposure to outcome.
What is the formula for prevalence in terms of cases and total population?

$\text{Prevalence} = \frac{\text{existing cases}}{\text{total population}}$ . Proportion of population with disease at a point in time.
What is the incidence of a disease?

Number of new cases in a population over a time period. Measures disease onset rate; denominator is at-risk population.
What is a risk factor in epidemiology?

Exposure or characteristic associated with increased disease likelihood. Identifies targets for prevention by raising disease probability.
What is mortality (as used in epidemiology)?

Death rate within a population. Measures deaths, distinct from morbidity which measures illness.
What is the definition of morbidity in public health?

Illness, disability, or reduced functioning due to disease. Disease impact beyond death (quality of life).
What is a confounder in an observational study?

A third variable linked to exposure and outcome. Can create false associations if not controlled.
What is the definition of life expectancy as a population health measure?

Average number of years a person is expected to live. Statistical estimate based on current mortality patterns.
What is the definition of a risk factor in epidemiology?

A characteristic associated with increased probability of disease. Risk factors identify modifiable or non-modifiable elements that elevate disease likelihood, guiding prevention efforts.
What is the definition of prevalence in epidemiology?

All existing cases in a population at a given time. Includes both new and old cases at one point in time.
If disease prevalence increases and sensitivity/specificity stay constant, what happens to PPV?

PPV increases. More disease cases increase true positives relative to false positives.
State the formula for cumulative incidence over a specified time period.

$\text{Cumulative incidence} = \frac{\text{new cases}}{\text{population at risk}}$ . Proportion developing disease during specified period.
Which measure is most appropriate for studying chronic diseases: incidence or prevalence?

Prevalence. Long duration makes total cases more informative than new cases.
What is the definition of an endemic disease pattern?

Constant, baseline presence of a disease in a region. Endemic patterns indicate stable, predictable disease occurrence, often due to ongoing transmission factors in the area.
What does a high prevalence with low incidence most strongly suggest about a disease?

Long duration or low mortality (cases accumulate over time). Chronic diseases accumulate cases when people live long with the condition.
What is the biopsychosocial model of health?

Health shaped by biological, psychological, and social factors. Integrates multiple domains for comprehensive health understanding.
Which measure is most useful for estimating disease burden at one time point: incidence or prevalence?

Prevalence. Captures total disease burden at a single time point.
What is the definition of case fatality rate (CFR)?

Proportion of diagnosed cases that die from the disease. CFR assesses disease lethality by measuring the fraction of cases resulting in death, informing treatment urgency.
Which study design starts with disease status and looks backward for prior exposures?

Case-control study. Retrospective design efficient for rare diseases.
What is the definition of a protective factor in epidemiology?

A characteristic associated with decreased probability of disease. Protective factors mitigate disease risk through behaviors, genetics, or environments that enhance resilience.
State the formula for cumulative incidence using new cases and population at risk.

$\text{Incidence} = \frac{\text{new cases}}{\text{population at risk}}$ . Rate of new disease development in at-risk group.
What is the definition of mortality as used in public health?

Death rate or frequency of death in a population. Specifically refers to deaths, unlike morbidity.
What is the definition of sensitivity for a diagnostic test?

Probability the test is positive given disease is present. High sensitivity minimizes false negatives.
State the formula for odds ratio using a $2\times^2$ table cells $a,b,c,d$ .

$OR=\frac{ad}{bc}$ . Cross-product ratio from contingency table.
What is the main measure of association typically produced by a cohort study?

Relative risk. Compares disease risk between exposed and unexposed.
What study design follows exposed and unexposed groups forward to compare incidence?

Cohort study. Prospective design allows direct incidence calculation.
What is the definition of health inequities (as distinct from disparities)?

Disparities that are unjust, preventable, and socially produced. Adds ethical dimension - these differences violate fairness principles.
Identify the study design that starts with outcome status and looks back for prior exposures.

Case-control study. Retrospective design; efficient for rare diseases.
What is the definition of epidemiology?

Study of disease distribution and determinants in populations. Tracks patterns to identify causes and prevention strategies.
What is the definition of incidence in epidemiology?

Number of new cases in a population over a time period. Measures disease onset rate, not existing cases.
What is selection bias in health research?

Sampling that makes participants systematically unrepresentative. Non-random sampling creates groups that don't represent the population.
What is confounding in epidemiology?

Distortion from a third variable related to exposure and outcome. Creates spurious associations; controlled by adjustment methods.
What is the definition of positive predictive value (PPV)?

Probability of disease given a positive test result. Depends on test accuracy and disease prevalence.
What is the definition of relative risk (risk ratio) in a cohort study?

$RR=\frac{\text{risk in exposed}}{\text{risk in unexposed}}$ . Compares disease risk between exposed and unexposed groups.
Identify the study design that assesses exposure and outcome at a single point in time.

Cross-sectional study. Provides snapshot prevalence but can't establish causation.
Which study design is most efficient for rare diseases: cohort or case-control?

Case-control. Starts with cases, making rare outcomes feasible to study.
What is the definition of epidemiology in public health?

Study of disease distribution and determinants in populations. Focuses on patterns and causes across groups, not individuals.
What is sensitivity in the context of a diagnostic test?

Probability a test is positive given disease is present. True positive rate; identifies diseased individuals correctly.
What is the key relationship between prevalence, incidence, and disease duration?

$\text{Prevalence}\approx \text{Incidence}\times \text{Duration}$ . This approximation holds in steady-state conditions where inflow (new cases) balances outflow (recovery or death).
State the formula for relative risk using incidence in exposed and unexposed groups.

$RR=\frac{I_{exposed}}{I_{unexposed}}$ . Ratio of incidence rates quantifies exposure impact.
State the formula for negative predictive value (NPV).

$NPV=\frac{TN}{TN+FN}$ . True negatives divided by all negative test results.
What is the difference between an epidemic and a pandemic?

Epidemic = regional outbreak; pandemic = worldwide spread. Geographic scope distinguishes these outbreak classifications.
State the formula for positive predictive value (PPV).

$PPV=\frac{TP}{TP+FP}$ . True positives divided by all positive test results.
What is the definition of confounding in an observational study?

A third variable distorts the exposure–outcome association. Must be related to both exposure and outcome.
What is selection bias?

Systematic error from nonrandom selection into a study or groups. Threatens internal validity; participants differ systematically.
What is the definition of incidence in epidemiology?

Number of new cases in a population during a time period. Measures disease occurrence rate, not total burden.
What is the definition of negative predictive value (NPV)?

Probability of no disease given a negative test result. How confident you can be in a negative result.
What is the definition of prevalence (as used in epidemiology)?

Total number of existing cases in a population at a given time. Includes both new and old cases at a specific point.
What is the definition of sensitivity of a diagnostic test?

Probability test is positive given disease is present. True positive rate; high sensitivity rules out disease when negative.
What is the definition of epidemiology in public health?

Study of disease distribution and determinants in populations. Focuses on patterns and causes at the population level.
What is the definition of a pandemic?

An epidemic spread across multiple countries or continents. Pandemics involve widespread transmission, necessitating global coordination for containment and mitigation.
What is the biopsychosocial model of health?

Health explained by interacting biological, psychological, and social factors. Integrates multiple domains affecting health outcomes.
Which measure tends to increase when disease duration increases (with stable incidence)?

Prevalence. Longer survival means more cases accumulate over time.
What is the biomedical model of health in terms of how it defines disease and treatment?

Disease as biological pathology; treatment targets physiological causes. Focuses solely on physical/biological causes, ignoring mental and social factors.
What is social support, and what is its general relationship to health outcomes?

Perceived/received help; generally predicts better health outcomes. Social connections buffer stress and promote healthy behaviors.
If $RR=1$ , what is the interpretation regarding exposure and disease risk?

No association between exposure and disease risk. Equal risk in both groups indicates exposure doesn't affect disease.
What is the definition of health disparities in social epidemiology?

Systematic, avoidable health differences between social groups. Emphasizes differences are not random but linked to social position.
What is the biopsychosocial model of health?

Health arises from interacting biological, psychological, and social factors. Integrates mind, body, and environment in understanding health.
State the formula for cumulative incidence (risk) over a time interval.

$\text{risk}=\frac{\text{new cases}}{\text{population at risk}}$ . Cumulative incidence measures probability over time.
What is the definition of mortality rate?

Deaths in a population per unit time. Usually expressed per 1,000 or 100,000 population.
What is the defining feature of a randomized controlled trial (RCT)?

Random assignment to intervention versus control conditions. Randomization minimizes bias and confounding between groups.
What is the definition of incidence (as distinct from prevalence) in epidemiology?

Number of new cases in a population over a time period. Measures disease onset rate, not total burden.
What is the best measure (incidence or prevalence) for evaluating risk of developing a disease?

Incidence. New cases show risk of getting disease.
What is the Hawthorne effect in research on health behaviors or outcomes?

Behavior changes because participants know they are observed. Observation itself alters the measured behavior.
What is the definition of odds ratio (OR) as used in case-control studies?

$OR=\frac{\text{odds of exposure in cases}}{\text{odds of exposure in controls}}$ . Compares exposure odds between cases and controls.
What is the biopsychosocial model of health in terms of factors included in illness and care?

Health reflects biological, psychological, and social factors. Integrates physical, mental, and social dimensions of health.
State the formula for specificity using a $2\times^2$ table.

$\text{specificity}=\frac{TN}{TN+FP}$ . True negatives divided by all without disease.
What is the key limitation of cross-sectional studies for causal inference?

They cannot establish temporality. Can't determine if exposure preceded outcome.
What is the main measure of association typically produced by a case-control study?

Odds ratio. Compares odds of exposure between cases and controls.
What is the definition of an odds ratio (OR) in epidemiology?

Odds of exposure in cases divided by odds of exposure in controls. Compares exposure odds between diseased and healthy groups.
What is the definition of health disparity (health inequity) on the MCAT?

Systematic, avoidable health differences linked to social disadvantage. Unjust differences rooted in social determinants, not biology alone.
What is the definition of mortality?

Death in a population. Specifically refers to deaths, not illness.
State the formula for negative predictive value (NPV) using $TN$ and $FN$ .

$\text{NPV}=\frac{TN}{TN+FN}$ . True negatives divided by all negative tests.
What is a confounder in an epidemiologic association between exposure and outcome?

Third variable related to both that distorts the true association. Must be associated with both exposure and outcome.
What is recall bias, and which study type is especially vulnerable to it?

Differential memory of exposure; common in case-control studies. Cases may remember exposures more vividly.
What is the definition of a health disparity (health inequality) between groups?

Systematic differences in health outcomes between populations. Can be based on race, income, geography, or other factors.
What is a confounder in an epidemiologic study?

A third variable linked to both exposure and outcome. Can create false associations if not controlled in analysis.
Which measure is typically higher for chronic diseases: incidence or prevalence?

Prevalence. Chronic diseases accumulate cases over time.
What is incidence in epidemiology?

Number of new cases in a population over a specified time period. Measures disease onset rate, not total burden.
What is the definition of an outbreak in epidemiology?

Disease cases above expected levels in a defined place/time. Localized increase beyond normal baseline.
What is the definition of the social gradient in health?

Stepwise health improvements with higher socioeconomic status. Shows linear relationship between SES and health.
What is selection bias in epidemiologic research?

Systematic differences from how participants are selected or retained. Non-random sampling affects study validity.
What is the key feature that distinguishes a cohort study design?

Groups are defined by exposure and followed for outcomes. Prospective design: exposure precedes outcome.
What is a protective factor in epidemiology?

An exposure associated with decreased probability of an outcome. Reduces disease risk when present.
What is the definition of prevalence in epidemiology?

Total existing cases in a population at a given time. Prevalence quantifies the proportion of a population affected by a condition at a specific point, reflecting overall disease burden.
What is a confounder in an epidemiologic study?

Third variable related to both exposure and outcome that distorts association. Must be associated with both to create spurious relationships.
What is the definition of a placebo effect?

Symptom change due to treatment expectations rather than active agent. Mind-body connection influences perceived benefit.
Identify the correct level of prevention: screening to detect disease early.

Secondary prevention. Catches disease early when treatment is most effective.
What is the definition of recall bias in observational studies?

Differential accuracy of remembered past exposures. Common when cases remember exposures better than controls.
What is iatrogenic illness?

Harm or illness caused by medical treatment. Unintended negative consequence of medical intervention.
What is confounding in an epidemiologic study?

A third variable distorts the exposureoutcome association. Creates spurious relationships by influencing both variables.
What is cultural competence in health care delivery?

Effective care that respects patients' cultural beliefs and practices. Adapts care delivery to align with patients' cultural backgrounds.
What is the best measure (incidence or prevalence) for estimating disease burden in a population?

Prevalence. Total cases show current disease burden.
What is the definition of a risk factor in epidemiology?

A characteristic associated with increased probability of disease. Exposure increases disease likelihood.
Which option best describes the sick role in functionalist theory?

Exempt from duties but obligated to seek help and want to get well. Parsons' concept balances rights with recovery responsibilities.
What is the definition of access to health care in population health contexts?

Ability to obtain needed health services in a timely manner. Encompasses availability, affordability, and acceptability.
What is the definition of access to care as a health system concept?

Ability to obtain timely, appropriate health services when needed. Encompasses availability, affordability, and acceptability.

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