BCSE Preventive Medicine and Public Health 4 — Questions and Answers
Question 1: In occupational health, the Threshold Limit Value (TLV) represents:
- The lethal concentration for 50% of exposed animals
- The maximum airborne concentration to which nearly all workers can be repeatedly exposed without adverse effects (Correct answer)
- The concentration requiring immediate evacuation
- The minimum detectable concentration of a substance
Correct answer: The maximum airborne concentration to which nearly all workers can be repeatedly exposed without adverse effects
TLVs are guidelines set by ACGIH representing levels for repeated daily occupational exposure without adverse health effects for nearly all workers.
Question 2: Which vaccine-preventable disease has a global eradication goal as of current WHO targets?
- Measles
- Poliomyelitis (Correct answer)
- Tetanus
- Diphtheria
Correct answer: Poliomyelitis
The Global Polio Eradication Initiative aims to eradicate all wild poliovirus strains, following smallpox as the second human disease to be eradicated.
Question 3: A number needed to treat (NNT) of 20 means:
- 20 patients must be treated for one to be harmed
- 20 patients must be treated for one to benefit (Correct answer)
- The treatment is 20% effective
- 20% of patients will experience side effects
Correct answer: 20 patients must be treated for one to benefit
NNT = 1 / absolute risk reduction; an NNT of 20 means 20 patients must receive treatment for one additional patient to benefit.
Question 4: The concept of 'primordial prevention' focuses on:
- Preventing relapse in recovered patients
- Preventing disease risk factors from emerging in the first place (Correct answer)
- Early detection through screening programs
- Genetic counseling before conception
Correct answer: Preventing disease risk factors from emerging in the first place
Primordial prevention addresses societal and environmental conditions to prevent the emergence of risk factors for disease.
Question 5: Which study design provides the strongest level of evidence for establishing causation?
- Cross-sectional survey
- Case-control study
- Randomized controlled trial (Correct answer)
- Ecological study
Correct answer: Randomized controlled trial
Randomized controlled trials provide the strongest evidence by randomly assigning subjects to treatment and control groups, controlling for confounding.
Question 6: The Apgar score assesses newborn status at 1 and 5 minutes after birth using which five criteria?
- Activity, Pulse, Grimace, Appearance, Respiration (Correct answer)
- Alertness, Pupil response, Grip, Auditory response, Reflexes
- Acrocyanosis, Pulse, Grunting, Axial tone, Reflexes
- Arousal, Perfusion, Gastrointestinal function, Ambulation, Respiratory rate
Correct answer: Activity, Pulse, Grimace, Appearance, Respiration
The Apgar score uses Activity (muscle tone), Pulse, Grimace (reflex irritability), Appearance (color), and Respiration, scored 0-2 each.
Question 7: Population-attributable risk (PAR) is most useful for:
- Determining individual patient prognosis
- Estimating the public health impact of eliminating a risk factor (Correct answer)
- Calculating the efficacy of a drug in clinical trials
- Measuring dose-response relationships
Correct answer: Estimating the public health impact of eliminating a risk factor
PAR estimates how much disease in the total population is attributable to a risk factor and what would be prevented if that factor were eliminated.
BCSE Preventive Medicine and Public Health 4
In occupational health, the Threshold Limit Value (TLV) represents: