Chamberlain College of Nursing NR503 Epidemiology Midterm Exam Chamberlain NR 503 Midterm Exam Population Health, Epidemiology & Statistical Principles (New )

Chamberlain College of Nursing NR503 Epidemiology Midterm Exam Chamberlain NR 503 Midterm Exam Population Health, Epidemiology & Statistical Principles (New ) NR 503 MIDTERM Enhanced Population Health, Epidemiology & Statistical Principles Study Guide Original, expanded exam-preparation resource inspired by the publicly visible topic areas of the referenced Stuvia material. Use note: This guide does not reproduce the paid/locked source. It develops original explanations, examples, mnemonics, and practice questions around the same subject matter. Course materials, instructor guidance, and current evidence should take precedence. NR503 Enhanced Study Guide • Original educational resource Page 2 How to Use This Guide Study in three passes: first learn the concepts, second work the calculation and interpretation examples without looking at the answers, and third complete the practice exam under timed conditions. The goal is not memorization alone: many epidemiology questions are solved by identifying the denominator, time direction, study design, or screening-test quadrant. High-Yield Topic Map Domain Know cold Common trap Population health aggregate, community, outcomes, risk confusing population-level care with one-patient care Disease frequency incidence vs prevalence; morbidity vs mortality using total cases when the question asks for new cases Prevention primary, secondary, tertiary calling treatment of established disease primary Surveillance passive, active, sentinel; collection-to-action cycle assuming surveillance is the same as screening Study design RCT, cohort, case-control, cross-sectional choosing a design from the wrong time direction Screening sensitivity, specificity, PPV, NPV forgetting predictive values depend strongly on prevalence Biostatistics mean/median/mode, spread, CI, p-value equating statistical significance with clinical importance Bias/confounding selection, information, recall, confounding treating confounding as random error Outbreaks case definition, epi curve, attack rate confusing attack rate with incidence rate NR503 Enhanced Study Guide • Original educational resource Page 3 1. Population Health & Epidemiology Foundations Core idea Epidemiology studies the distribution and determinants of health-related states or events in populations and applies that knowledge to control health problems. Population health adds a broader focus on outcomes, risk, demographics, environments, systems, and inequities across groups. Key terms • Aggregate: a defined group sharing a characteristic, risk, geography, diagnosis, occupation, age, or other trait. • Community: a population made up of multiple interacting aggregates, often linked by geography or shared context. • Data: collected observations or measurements; information is produced when data are organized and interpreted. • Outcome: a measurable end result associated with a disease, intervention, service, or population condition. • Morbidity: illness or disease burden. Mortality: death. • High-risk group: a population with elevated probability of an adverse outcome compared with a reference group. Exam lens Ask: Is the question about one patient, a defined group, or an entire community/population? Epidemiology questions usually require a population denominator. NR503 Enhanced Study Guide • Original educational resource Page 4 2. Incidence & Prevalence Incidence Incidence concerns new cases during a specified period among people at risk of becoming cases. A useful simplified form is: new cases ÷ population at risk during the period. Incidence is especially useful for studying risk and possible causes. Prevalence Prevalence concerns existing cases in a population at a point or during a period. Point prevalence asks about a particular time; period prevalence covers a specified interval. Relationship Prevalence is influenced by both incidence and disease duration. A chronic disease can have high prevalence even if few new cases occur each year because people remain cases for a long time. Worked example A population has 50,000 people at risk. During one year, 500 new cases occur. Approximate cumulative incidence = 500/50,000 = 0.01 = 1%, or 10 per 1,000. If 2,000 people are currently living with the condition at a particular date, point prevalence = 2,000/50,000 = 4%. Mnemonic I = Incoming/new cases. P = Present/all existing cases. NR503 Enhanced Study Guide • Original educational resource Page 5 3. Rates, Ratios, Proportions & Denominators Core distinction A proportion has a numerator contained within the denominator. A ratio compares two quantities. A rate incorporates a time dimension or represents occurrence over time. Denominator discipline The denominator must represent the population actually capable of experiencing the event. Excluding people not at risk can change the estimate substantially. Classic trap For uterine cancer incidence, people without a uterus are not at risk of developing uterine cancer. Including them in the denominator can dilute the rate. Calculation strategy Before touching a calculator, underline: (1) new vs existing cases, (2) who is at risk, (3) time period, and (4) requested multiplier such as per 100, per 1,000, or per 100,000. NR503 Enhanced Study Guide • Original educational resource Page 6 4. Surveillance & Outbreak Investigation Surveillance Public-health surveillance is the continuing systematic collection, analysis, interpretation, and dissemination of health data so action can be taken. Types Passive: routine reporting by clinicians, laboratories, or facilities. Active: public-health personnel actively seek cases. Sentinel: selected sites provide detailed signals about trends. Syndromic: monitors symptom patterns before definitive diagnoses may be available. Outbreak workflow • Create a working case definition. • Verify that an outbreak is real rather than a reporting artifact. • Describe cases by time, place, and person. • Develop and test hypotheses about source and transmission. • Implement control measures appropriate to the evidence. • Communicate findings and continue monitoring. Epi curve A point-source outbreak often produces a relatively concentrated rise and fall; propagated outbreaks may show successive waves corresponding to transmission generations. Always interpret the curve with incubation period and exposure history. NR503 Enhanced Study Guide • Original educational resource Page 7 5. Levels of Prevention Primary Prevents disease before it occurs: vaccination, risk-factor reduction, health education, environmental controls, injury prevention. Secondary Detects disease early and initiates prompt management: screening and early diagnosis in appropriate populations. Tertiary Reduces complications, disability, or progression after disease is established: rehabilitation, chronic disease management, complication prevention. Exam rule If the intervention is aimed at preventing the initial onset, think primary. If it seeks earlier detection, think secondary. If disease already exists and the goal is to reduce consequences, think tertiary. NR503 Enhanced Study Guide • Original educational resource Page 8 6. Epidemiologic Study Designs Cross-sectional Exposure and outcome are assessed around the same time. Useful for describing prevalence and generating hypotheses, but temporal sequence can be difficult to establish. Case-control Start with people who have the outcome (cases) and people without it (controls), then look backward for prior exposures. Efficient for rare diseases or outcomes and often summarized with an odds ratio. Cohort Start with exposure status and follow people to compare outcome occurrence. Can be prospective or retrospective. Risk and incidence can often be estimated directly when follow