BCSE Preventive Medicine and Public Health 3 — Questions and Answers
Question 1: In a randomized controlled trial, allocation concealment is used primarily to prevent:
- Loss to follow-up
- Selection bias during enrollment (Correct answer)
- Information bias during outcome assessment
- Confounding by indication
Correct answer: Selection bias during enrollment
Allocation concealment prevents those enrolling participants from knowing upcoming treatment assignments, preventing selection bias.
Question 2: The PRECEDE-PROCEED model in health promotion planning begins with:
- Implementation of the intervention
- Social assessment and epidemiological diagnosis (Correct answer)
- Process evaluation
- Administrative and policy assessment
Correct answer: Social assessment and epidemiological diagnosis
PRECEDE begins with social and epidemiological assessment to identify quality of life concerns and health problems before planning interventions.
Question 3: Which waterborne disease is most associated with groundwater contamination from agricultural runoff containing nitrates?
- Hepatitis A
- Methemoglobinemia (blue baby syndrome) (Correct answer)
- Cryptosporidiosis
- Fluorosis
Correct answer: Methemoglobinemia (blue baby syndrome)
High nitrate levels in drinking water cause methemoglobinemia in infants, reducing blood oxygen-carrying capacity.
Question 4: An odds ratio of 1.0 in a case-control study indicates:
- Strong positive association between exposure and disease
- No association between exposure and disease (Correct answer)
- Strong negative association (protective effect)
- The study is underpowered
Correct answer: No association between exposure and disease
An odds ratio of 1.0 means the odds of exposure among cases equal the odds of exposure among controls, indicating no association.
Question 5: The Healthy People initiative in the United States sets national health objectives on a:
- 5-year cycle
- 10-year cycle (Correct answer)
- Annual basis
- 20-year cycle
Correct answer: 10-year cycle
Healthy People sets 10-year national health improvement goals, with iterations including Healthy People 2020, 2030, etc.
Question 6: Which occupational lung disease is caused by exposure to crystalline silica dust?
- Asbestosis
- Silicosis (Correct answer)
- Byssinosis
- Berylliosis
Correct answer: Silicosis
Silicosis is a fibrotic lung disease caused by inhalation of crystalline silica, common in mining and sandblasting workers.
Question 7: The Bradford Hill criterion of 'biological gradient' refers to:
- The plausibility of a biological mechanism
- A dose-response relationship between exposure and disease (Correct answer)
- Consistency of findings across different populations
- Specificity of the association
Correct answer: A dose-response relationship between exposure and disease
Biological gradient means that greater exposure generally leads to greater incidence of disease, supporting causality.
BCSE Preventive Medicine and Public Health 3
In a randomized controlled trial, allocation concealment is used primarily to prevent: