DQ 2 : Discuss three of the seven uses and applications of epidemiology
Three of the seven uses, and then a harder question about prediction. Descriptive epidemiology generates hypotheses and describes trends; treating it as forecasting is the error to avoid.
Editorial process
Last reviewed · August 18, 2026
Three of seven uses, then person, place and time
The seven uses come from Morris and are worth naming as a set before you choose three: studying the historical rise and fall of disease in a population, community diagnosis, assessing how individual risks average out at population level, completing the clinical picture of a disease, identifying syndromes, working out the causes of health and disease, and evaluating health services. Pick three that let you say different things. Community diagnosis is the one closest to public health nursing practice, since it produces the profile a programme is planned against. Completing the clinical picture is worth choosing because it is the least obvious — it is how a condition's full spectrum, including its mild and asymptomatic forms, becomes visible when clinicians only ever see the severe end. Evaluating health services connects epidemiology to programme work directly. Naming the whole set first shows the marker you did not simply pick the three you had heard of.
For the second half, be precise about what descriptive epidemiology can and cannot do. Person, place and time organise data so patterns become visible: person covers age, sex, occupation, ethnicity and behaviour; place covers geography, urban and rural, and clustering; time covers secular trends, seasonality, epidemic curves and cohort effects. Together they generate hypotheses that analytic studies then test — the classic case is John Snow mapping cholera deaths by water supply, which is descriptive work that produced a testable causal claim. On prediction, the honest position is that descriptive epidemiology supports forecasting by establishing baselines and trends rather than by forecasting directly. A seasonal pattern tells you when to prepare; an age distribution combined with population projections tells you how demand will change; a cluster tells you where to look now. Say what a prediction from descriptive data assumes — that the pattern's underlying causes persist — and you have answered a question most posts answer by asserting that trends continue.
Likely learning objectives
- Name the seven uses of epidemiology and select three deliberately.
- Explain community diagnosis and its role in programme planning.
- Describe the person, place and time triad with real variables.
- State precisely what descriptive data can support in a prediction.
Assignment instructions
Read the full question
Review every instruction before using the planning guidance that follows.
PUB 540 Topic 1 DQ 2 DQ 2 : Discuss three of the seven uses and applications of epidemiology Discuss three of the seven uses and applications of epidemiology. How can descriptive epidemiology (person, place, time) be used to study health and illness and predict future trends?
Turn the brief into deliverables
- 01The seven uses named, with three developed.
- 02A reason for each of the three choices.
- 03The person, place and time triad with concrete variables.
- 04A historical or current example of hypothesis generation.
- 05An accurate account of what prediction from descriptive data assumes.
The three uses, then descriptive epidemiology and prediction
The seven, and why these three
Name the full set and justify the selection.
What the assessor is likely looking for
A selection criterion rather than an arbitrary three.
Use one: community diagnosis
Show how it produces the profile a programme is planned against.
What the assessor is likely looking for
A link from the diagnosis to a planning decision.
Use two and three
Develop two further uses that differ in kind. Naming the set first also shows the marker you did not simply pick the three you had heard of.
What the assessor is likely looking for
Two uses that could not be merged into one.
Person, place and time
Set out the triad with concrete variables in each.
What the assessor is likely looking for
Variables specific enough to be collected.
From description to prediction
State what descriptive data supports and what it assumes.
What the assessor is likely looking for
The persistence assumption named explicitly.
Where the seven uses are enumerated
Recommended databases
- NCBI Bookshelf
- PubMed Central
- Centers for Disease Control and Prevention
- Office of Disease Prevention and Health Promotion
Search sequence
- 1.Find a source enumerating the seven uses before selecting three.
- 2.Read an epidemiological measures reference for the descriptive variables.
- 3.Find a documented example where descriptive work generated a testable hypothesis.
- 4.Check a surveillance report to see how a trend is actually presented.
Reference shortlist
These are authoritative starting points, not a ready-made bibliography. A qualified reviewer must confirm that each source fits the assignment and supports the claim beside which it is cited.
Epidemiology Morbidity And Mortality
StatPearls, NCBI Bookshelf · 2023
Epidemiology of morbidity and mortality — the measures descriptive epidemiology works with.
Epidemiology Of Study Design
StatPearls, NCBI Bookshelf · 2023
Study design across epidemiology, for where descriptive work sits relative to analytic study.
Applying the Bradford Hill criteria in the 21st century: how data integration has changed causal inference in molecular epidemiology
PubMed Central · 2015
Applying causal criteria in the modern era — the step beyond description.
Leading Health Indicators - Healthy People 2030
Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services · 2024
National indicators and trend data, for how baselines are published.
Study Bias
StatPearls, NCBI Bookshelf · 2023
Study bias, for the limits of inferring from descriptive patterns.
Review before submission
Common mistakes
- Choosing three uses that overlap heavily.
- Treating descriptive epidemiology as causal or predictive by itself.
- Listing person, place and time without variables underneath them.
- Asserting that trends continue without naming the assumption.
Submission checklist
- Have you named all seven before developing three?
- Do your three uses say genuinely different things?
- Does each element of the triad have real variables?
- Have you given an example of hypothesis generation?
- Have you stated the assumption behind any prediction?
Use this guide to plan and review your own work. Follow your institution's rules and read Brinevia's academic-integrity policy.
Written by
Maren Caldwell
MSN, RN, CNE
Medical-surgical nursing, pharmacology and NCLEX preparation
Maren is a registered nurse with over 15 years of clinical and educational experience in medical-surgical nursing. She writes on NCLEX preparation, patient care fundamentals, pharmacology and evidence-based practice.
Reviewed by
Dr. Tessa Redmond
DNP, RN, CNE
Evidence-based practice and clinical education
Tessa is a doctorally-prepared nurse educator. She reviews Brinevia content for clinical accuracy and alignment with current evidence-based guidelines.