how does a double blind experiment work

HESI LPN

LPN Nutrition Practice Test

1. How does a double-blind experiment work?

A. Both subject groups take turns receiving each treatment.
B. Neither subjects nor researchers know which subjects are in the control or experimental group.
C. Neither group of subjects knows whether they are in the control or experimental group, but the researchers do not know.
D. Both subject groups know whether they are in the control or experimental group, but the researchers do not know.

Correct answer: B

Rationale: The correct answer is B. In a double-blind experiment, neither the subjects nor the researchers know which subjects are in the control or experimental group. This helps to eliminate bias and ensure that the results are more objective. Choice A is incorrect as in a double-blind experiment, subjects do not take turns receiving each treatment; it is about masking the treatment allocation. Choice C is incorrect because it implies that the researchers are aware of the group allocation, which goes against the principle of blinding in a double-blind study. Choice D is incorrect as both subject groups should not know whether they are in the control or experimental group to maintain the blindness of the study.

2. What is a common clinical manifestation of Kawasaki disease?

A. Severe headaches
B. High fever lasting more than 5 days
C. Chronic cough
D. Severe abdominal pain

Correct answer: B

Rationale: A high fever lasting more than 5 days is a common clinical manifestation of Kawasaki disease. This fever is often accompanied by other symptoms such as rash and conjunctivitis. Severe headaches (Choice A), chronic cough (Choice C), and severe abdominal pain (Choice D) are not typically associated with Kawasaki disease, making them incorrect choices.

3. What is the primary goal in managing a child with asthma?

A. Prevent triggering asthma attacks
B. Avoid triggering asthma attacks
C. Administer corticosteroids
D. Increase physical activity

Correct answer: B

Rationale: The primary goal in managing a child with asthma is to avoid triggering asthma attacks. This involves managing allergens, ensuring proper medication use, and creating an asthma action plan. Choice A is incorrect because the goal is to avoid triggering asthma attacks, not necessarily to prevent recurrent infections. Choice C is incorrect as corticosteroids are a treatment option but not the primary goal of asthma management. Choice D is incorrect because although physical activity is important, the primary goal is to prevent asthma attacks and manage symptoms effectively.

4. What is the primary reason influencing most people's food choices?

A. cost
B. taste
C. convenience
D. nutritional value

Correct answer: B

Rationale: The primary reason most people choose the foods they eat is taste. While cost, convenience, and nutritional value also play a role in food choices, taste often takes precedence as people are more likely to select foods that they find appealing in flavor. Therefore, options A, C, and D are incorrect as taste is the chief factor influencing food choices.

5. What action should be taken for a 2-year-old with laryngotracheobronchitis in an oxygen tent?

A. Restrain the child and notify the healthcare provider
B. Increase the oxygen concentration
C. Take the child to the playroom
D. Ask the mother to help in comforting the child

Correct answer: B

Rationale: In laryngotracheobronchitis (croup), a child may become restless due to poor oxygenation. Increasing the oxygen concentration in the oxygen tent is crucial to improve oxygenation levels and manage symptoms effectively. Restraint is not appropriate in this situation, as it may cause distress and worsen the child's condition. Taking the child to the playroom is not indicated when the child requires oxygen therapy. While comforting the child is important, the priority in this scenario is to optimize oxygen delivery to improve respiratory distress.