Nokea
The balancing equation is
- A. P1+(B-D)+(I-E)=P2
- B. P1-(B-D)-(I-E)=P2
- C. P2+(B-D)+(I-E)=P1
- D. P1+P1(B-D)+P1(I-E)=P2
Correct Answer: A
Rationale: The balancing equation for population change is P1 + (B-D) + (I-E) = P2, where B is births, D is deaths, I is in-migration, and E is out-migration.
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Which surveillance can watch for disease before patient seeks care?
- A. Surveillance based on a specific case definition for a disease(e.g., listeriosis).
- B. Syndromic surveillance based on symptoms, signs, or other characteristics of a disease.
- C. Both.
- D. Neither.
Correct Answer: B
Rationale: Syndromic surveillance detects outbreaks based on early symptoms reported even before patients seek medical care.
How does the 'healthy worker effect' influence the interpretation of findings from occupational health research?
- A. It tends to decrease mortality differences between workers and the general population.
- B. It tends to increase mortality differences between workers and the general population.
- C. It has no impact on mortality comparisons.
- D. It only affects morbidity rates.
Correct Answer: A
Rationale: The healthy worker effect biases comparisons because workers are generally healthier than the general population, reducing apparent mortality differences.
Identify the type of study design described: The physical examination records of the incoming first-year class of 1935 at the University of Minnesota are examined in 1980 to see whether the freshmen's recorded height and weight at the time of admission to the university were related to their chance of developing coronary heart disease by 1981.
- A. Cohort study
- B. Case-control study
- C. Cross-sectional study
- D. Ecological study
Correct Answer: A
Rationale: This retrospective analysis constitutes a cohort study linking baseline characteristics to future outcomes.
A local health department epidemiologist investigated an outbreak of gastrointestinal illness thought to be associated with a college cafeteria. There were many complaints about the quality of the cafeteria's offerings, and it appeared that the students' worst expectations were confirmed when several students visited the college's infirmary during the middle of the night and the following day complaining of nausea, diarrhea, fever, vomiting, and cramps. The health department's investigation revealed that 24 students had eaten in the cafeteria immediately before the outbreak. The times between eating in the cafeteria and the development of active symptoms ranged from 20 to 36 hours. A list of foods eaten, the number of persons eating the foods, and tabulations of illness are presented in Appendix 12. Fill in the attack rates where indicated. On the basis of your calculations, answer the following questions: What food or foods would you suspect caused the problem?
- A. Chicken salad
- B. Potato salad
- C. Both A and B
- D. Neither A nor B
Correct Answer: C
Rationale: High attack rates for both chicken and potato salads suggest they were contaminated.
A random-digit dialed survey conducted in the City of Long Beach, California, reported that a greater proportion of nonsmokers endorsed a ban on smoking in alcohol-serving establishments than did smokers. What type of study design was this?
- A. Cross-sectional study
- B. Case-control study
- C. Ecologic study
- D. Cohort study
Correct Answer: A
Rationale: This is a cross-sectional study as it captures attitudes at one point in time without follow-up.