Free CPH Exam Flashcards

Three measures of central tendency. Mean = arithmetic average (sensitive to outliers). Median = middle value when sorted (robust to skew). Mode = most frequent value. For skewed data, the median best represents the typical value.

SD measures how spread out individual data points are around the mean. SE measures how precise the sample mean is as an estimate of the population mean. Formula: SE = SD / sqrt(n). SE shrinks as sample size grows; SD does not depend on n.

In a normal distribution: ~68% of values fall within 1 standard deviation of the mean, ~95% within 2 SD, and ~99.7% within 3 SD. Used to interpret z-scores and identify unusual values.

If sampling were repeated many times, 95% of the resulting intervals would contain the true population parameter. For a difference or ratio, a CI that excludes the null value (0 for mean difference, 1 for RR/OR) indicates statistical significance at alpha = 0.05.

Rejecting the null hypothesis when it is actually true — a false positive. Its probability equals the chosen significance level (commonly 0.05), meaning a 5% chance of finding an effect that does not exist.

Type II error = failing to reject a false null (false negative). Power = 1 - beta = probability of detecting a real effect. Power rises with larger sample size, larger effect size, and higher alpha.

H0 (null) states no association or no difference exists. H1 (alternative) states an association or difference exists. Reject H0 when p-value < alpha; fail to reject H0 when p-value >= alpha. Failing to reject is not proof that H0 is true.

Incidence = number of NEW cases in a time period divided by the population at risk. Prevalence = all EXISTING cases (new and old) at a point or period in time. Relationship: prevalence ≈ incidence x average disease duration.

The proportion of people exposed who become ill during an outbreak. Formula: (number of new cases among exposed) / (total exposed). Food-specific attack rates compare those who ate vs did not eat a food to identify the source.

Case fatality rate = deaths among diagnosed cases / total cases — measures disease severity. Mortality rate = deaths in a total population / population size — measures how common death from the disease is in the population.

Risk in the exposed divided by risk in the unexposed. Used in cohort studies. RR > 1 = increased risk; RR < 1 = decreased risk; RR = 1 = no association. A 95% CI excluding 1 indicates statistical significance.

Odds of exposure among cases divided by odds of exposure among controls. Used in case-control studies. OR > 1 = exposure associated with disease. OR approximates RR when the disease is rare (rare disease assumption).

A third variable distorts the true exposure-outcome relationship, making it appear stronger, weaker, or reversed. Controlled through randomization, matching, stratification, restriction, or multivariable regression.

Selection bias = systematic error in who enters or remains in the study (e.g., low response, referral patterns). Information bias = error in measuring exposure or outcome (e.g., recall error, misclassification of disease status).

From strongest to weakest: randomized controlled trial (random assignment, best for causation) > cohort (prospective follow-up, measures RR) > case-control (retrospective, measures OR) > cross-sectional (snapshot, prevalence) > ecological (group-level, cannot infer individual risk).

Passive: providers report cases voluntarily (common, low cost). Active: health department actively seeks cases. Sentinel: selected sites monitor trends (e.g., flu sentinel providers). Syndromic: pre-diagnostic data (ED chief complaints, over-the-counter sales) for early detection.

Sensitivity = proportion of true positives correctly identified (true positive rate); high sensitivity is best for screening to rule OUT disease. Specificity = proportion of true negatives correctly identified (true negative rate); high specificity rules IN disease. They trade off against each other.

Probability that a positive test result is a true case. Formula: true positives / (true positives + false positives). PPV rises with higher disease prevalence and higher specificity; it is not a fixed property of the test.

Major routes: inhalation, ingestion, and dermal absorption. A dose-response curve describes how the magnitude of a health response changes with exposure level. Threshold effects show a no-observed-effect level; non-threshold effects (e.g., carcinogens) assume risk exists at any dose above zero.

Endemic = baseline, expected level of disease constantly present in a population. Epidemic = cases exceeding the expected baseline in a population over a time period. Pandemic = an epidemic that spreads across multiple countries or continents.

Verify the outbreak and diagnosis, establish a case definition, find and count cases, describe by time/place/person, generate hypotheses, test hypotheses with an analytic study, implement control measures, and communicate findings. Done in roughly this order but steps overlap.

Screening is applied to asymptomatic people to identify those likely to have a condition (high sensitivity prioritized). Diagnostic testing confirms disease in symptomatic or screen-positive individuals (high specificity prioritized). Screening is not a substitute for diagnosis.

Medicare is a federal program primarily for people 65+ and certain younger people with disabilities or end-stage renal disease. Medicaid is a joint federal-state program for people with low income and limited resources. Both are administered under CMS.

Insurance exchanges/marketplaces, Medicaid expansion, essential health benefits, prohibition on denying coverage for pre-existing conditions, and dependent coverage to age 26. The federal individual mandate penalty was zeroed out starting in 2019, though some states maintain their own mandates.

Cost-benefit analysis monetizes all costs and benefits and compares them in dollars (net benefit). Cost-effectiveness analysis compares cost per health outcome, such as cost per life-year or per QALY gained. CEA is more common in public health because placing dollar values on health outcomes is difficult.

Line-item budgeting organizes spending by expenditure category (salaries, supplies, travel). Program budgeting organizes spending by program or activity so costs align with objectives and outcomes. Program budgeting supports evaluation of cost-effectiveness.

Track only allowable costs per the grant agreement, maintain documentation for audit, meet reporting deadlines, allocate shared costs properly, and avoid supplanting (using grant funds to replace existing budget). Noncompliance can trigger repayment or loss of future funding.

Identify all stakeholders, assess each by interest and influence, and map to a strategy: high influence/high interest = manage closely; high influence/low interest = keep satisfied; low influence/high interest = keep informed; low influence/low interest = monitor. Ensures the right parties are engaged.

Predicts health behavior from perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy. People act when they believe a threat is real, the action helps, and the barriers are surmountable.

Health is shaped across multiple levels: individual, interpersonal, organizational, community, and public policy. Interventions targeting more than one level are more effective than those targeting a single level, because behaviors are influenced by many contexts.

Stages: precontemplation, contemplation, preparation, action, maintenance, (termination). Interventions are most effective when matched to a person's stage (e.g., raise awareness in precontemplation, support skills in action).

Conditions in which people are born, grow, live, work, and age — including income, education, housing, and environment. These structural factors are major drivers of health disparities and often matter more than clinical care for population health outcomes.

Equality gives everyone the same resources regardless of need. Equity gives people what they need to reach their full health potential, removing unfair and avoidable differences. Equity targets root causes of disparities rather than uniform distribution.

The ability to work effectively with people of diverse backgrounds. Includes awareness of one's own bias, knowledge of other cultures, and skills to adapt communication and practice. Improves trust, reduces disparities, and supports equitable service delivery.

Autonomy: respect a person's self-determination. Beneficence: act for the benefit of others. Non-maleficence: do no harm. Justice: fair and equitable distribution of benefits and burdens. These guide public health and clinical decision-making.

Disclosure of risks, benefits, and alternatives; capacity to understand and decide; voluntariness (free of coercion); and comprehension. Required for research enrollment and many clinical procedures. Documented consent is the record, not the process itself.

An Institutional Review Board reviews research involving human subjects to protect their rights and welfare. It approves studies before enrollment, requires informed consent, minimizes risks, and monitors ongoing research. IRB approval is required regardless of funding source.

Protects the use and disclosure of protected health information (PHI) by covered entities (health plans, providers, clearinghouses). Applies the minimum necessary standard for non-routine disclosures and requires patient authorization for many secondary uses. Public health reporting is an permitted exception.

State police power allows government to restrict individual liberty to protect population health — isolation of infected people and quarantine of exposed contacts. Requires due process, the least restrictive means, and clear evidence of necessity.

A systematic process to identify gaps between current and desired conditions and prioritize where to act. Uses existing data, key informant interviews, surveys, and focus groups. Drives program planning by defining the target population and its priorities.

Inputs (resources), activities (what is done), outputs (products and services delivered), and outcomes (short, intermediate, and long-term changes). A logic model links program activities to intended results and identifies evaluation indicators.

Process evaluation assesses whether a program was implemented as planned — reach, dose delivered, fidelity, and participant satisfaction. Outcome evaluation assesses whether the program achieved its intended effects — short-term knowledge change and long-term health impact.

Formative evaluation occurs during program development to improve design and delivery. Summative evaluation occurs after completion to judge overall effectiveness and inform decisions about continuation, expansion, or scale-up.

Objectives should be Specific, Measurable, Achievable, Relevant, and Time-bound. SMART objectives make evaluation possible by defining exactly what success looks like and when it should be achieved.

Using the best available research evidence, combined with community input and contextual data, to develop and implement programs. Moves decisions beyond anecdote and habit toward interventions with demonstrated effectiveness in similar settings.

Be first and fast, acknowledge uncertainty, be transparent, provide actionable guidance, and tailor messages to the audience. Trust is built before a crisis, not during one. Listening and two-way dialogue matter as much as messaging.

The degree to which people can obtain, process, and understand health information needed to make decisions. Plain language (around a 6th grade reading level) improves comprehension. Limited health literacy is linked to poorer health outcomes and higher costs.

Mass media (broad reach, low control), interpersonal (two-way, supports behavior change), social media (rapid, interactive), and community channels (trusted local voices). Match the channel to the audience, objective, and message complexity.

Treating a problem as part of an interconnected whole rather than isolated parts. Emphasizes feedback loops, unintended consequences, and leverage points. Well suited to complex public health problems where interventions in one area affect others.

Diverse stakeholders united around a shared goal. Strengths: pooled resources, broader reach, shared ownership, and greater legitimacy. Requires clear governance, defined roles, mutual benefit, and sustained communication to survive member turnover and competing priorities.