CSP-11 CSP-11 D6.02 · Domain 6 · Occupational Health and Applied Science · 10%
Public Health / Epidemiology
A plant clinic finds 40 workers with current dermatitis among 200 examined on one date. Management calls this the annual incidence and proposes more gloves. The HSE specialist must identify what the count actually measures, obtain new-case and exposure histories, and investigate the products and tasks before selecting controls.
Updated . Independent CSP-11 practice. Not BCSP-endorsed. No pass guarantee.
Decision rule
Epidemiology describes association in a defined population. It is not a hierarchy row.
Incidence vs prevalence. RR and OR need a 2×2 with denominators. BEI is not a PEL.
In 20 seconds
- Epidemiology describes association in a defined population.
- It is not a hierarchy row.
- Public health/epidemiology: rates, populations at risk, association vs causation.
- Standardize rates; watch healthy worker effects and confounders.
How to apply Public Health / Epidemiology
THEORY: Define cases, time, and workers at risk. Bias and confounding before causation. A cluster needs exposure reconstruction, not a press release. CALC: If a stem gives a 2×2, compute RR or OR only as asked. Do not invent cells. FIELD: Three illness reports on one shift. Define the case, the population, and the shared task before concluding an outbreak. ASSESS: One case as proof of an epidemic, or BEI as a PEL, is the trap.
Worked case
Wrong first move: Declare causation from rumor. Correct move: Define case and population; keep BEI off the pyramid.
Why the rule holds
Related: 100 wait no — 132, 37, 68.
Same rule, different setting
A camp records 15 new gastrointestinal cases among 300 workers during a 3-day outbreak, while another dashboard shows 40 workers currently sick. Operations mixes attack rate, prevalence, and incidence. You are the CSP. The decision is which measure answers which operational question and what action the data justify.
A project compares respiratory symptoms in workers assigned to a demolition area with workers on the office side. Management reports “double the prevalence” and calls that causation. You are the CSP. The task is to distinguish association from causation and use the correct epidemiologic measure.
Picture / model
Define disease and population → identify new or current cases → choose people or person-time denominator → calculate prevalence, incidence or association → examine timing, bias and confounding → control the credible exposure pathway → reassess using the same definitions. A risk ratio measures association; it does not establish cause.
Exam traps
Original SafePath contrasts for Public Health / Epidemiology. These are study traps, not recalled BCSP items.
| Trap | Correct read |
|---|---|
| Incidence | New cases over a defined at-risk population/time |
| Prevalence | Existing cases at a point/period |
| RR | Risk in exposed divided by risk in unexposed |
| Risk difference | Absolute excess risk: exposed risk − unexposed risk |
| Association | Statistical relationship that still requires causal evaluation |
Field move
40/200 = 0.20. Existing cases at one time are a prevalence-style proportion, not an incidence rate.
Scenarios
Scenario 1 · Fundamental · CSP-11 D6.02
Forty workers currently have dermatitis out of 200 workers. Which measure is being described?
Best action: Point prevalence-style proportion.
Why: The proportion currently affected is 40/200 = 0.20. Because the stem counts existing cases rather than new cases over time, the measure is a point-prevalence-style proportion. Incidence and attack rate need new cases in a defined period.
Scenario 2 · Applied Scenario · CSP-11 D6.02
A cohort records 15 new cases among 300 exposed workers during a defined outbreak. What is the attack rate?
Best action: 5%.
Why: Attack rate for this outbreak is 15/300 = 0.05 = 5%. A different denominator, a fourfold product, or a tenfold product is not that quotient.
Scenario 3 · Fundamental · CSP-11 D6.02
For the same 5% versus 2% risks, what is the absolute risk difference?
Best action: 3 percentage points.
Why: Risk difference is 0.05 − 0.02 = 0.03, which is 3 percentage points. Relative risk is 2.5. The reversed ratio and the sum of the risks are different measures.
If the stem says this
| Stem signal | Best direction |
|---|---|
| raw counts compared across unequal populations | use rates |
| correlation treated as proof of cause | seek stronger causal evidence |
| cluster found | investigate systematically |
| two answers work | higher hierarchy / system / design |
| exposure cause likely and control open | control while investigating |
Check before you leave
- ✓ Public health/epidemiology: rates, populations at risk, association vs causation.
- ✓ Standardize rates; watch healthy worker effects and confounders.
- ✓ Surveillance systems detect clusters that need investigation.
- ✓ Interventions evaluated with appropriate designs when possible.
- ✓ Communication of risk must be accurate and actionable.
- ✓ Workplace exposures can create community impacts.
Blueprint mapping
Public Health / Epidemiology is the SafePath study class for CSP-11 D6.02 inside CSP-11 Domain 6, Occupational Health and Applied Science (10%). This domain combines occupational hygiene with applied science: exposure assessment, public health, toxicology, ergonomics, chemistry, and physics.
SafePath uses the publicly posted CSP-11 outline as a study map. It does not reproduce official exam content, and it is not affiliated with or endorsed by BCSP or Pearson VUE.
Practice / flashcards / formulas
More classes in Occupational Health and Applied Science
Nearby lessons mapped to the same CSP-11 domain.
CSP-11 D6.02
Other classes on this task
Guides that use Public Health / Epidemiology
- CSP calculationsIncident rates, noise, ventilation, and unit checks
- Formula deskNamed expressions used in occupational-health items
- Manufacturing safety study guideExposure, noise, and process controls
- CSP-11 exam prep guideDomain weights, sample items, and a study sequence
- CSP-11 blueprint and weightsSeven published domains and the class map
Public Health / Epidemiology study questions
- What decision does the Public Health / Epidemiology class train?
- Epidemiology describes association in a defined population. It is not a hierarchy row. This is independent SafePath CSP practice for CSP-11 D6.02. It is not an official BCSP item and it is not a pass guarantee.
- What exam trap shows up in Public Health / Epidemiology?
- A common miss treats this as sufficient: Incidence The stronger read is: New cases over a defined at-risk population/time
- How does Public Health / Epidemiology map to the CSP-11 blueprint?
- SafePath maps this class to CSP-11 D6.02 in Domain 6, Occupational Health and Applied Science (10% of the published blueprint). Use the public outline for study planning. SafePath is not affiliated with or endorsed by BCSP.
Verify
Verify: Confirm current certification requirements with BCSP and technical requirements with the cited authoritative standard.