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. How should a healthcare provider respond to a parent concerned about their child's sleep pattern?

A. Recommend a sleep study
B. Suggest increasing daytime naps
C. Provide education on sleep hygiene
D. Advise on medication use

Correct answer: C

Rationale: When a parent expresses concerns about their child's sleep pattern, providing education on sleep hygiene is a beneficial response. Teaching parents about establishing a consistent sleep routine, creating a conducive sleep environment, and promoting healthy sleep habits can help address the child's sleep issues. This empowers the parent to make positive changes that can improve the child's sleep patterns. Recommending a sleep study (Choice A) may be premature and unnecessary without first addressing basic sleep hygiene. Suggesting increasing daytime naps (Choice B) may not always be appropriate and could further disrupt the child's nighttime sleep. Advising on medication use (Choice D) should be considered only after other non-pharmacological approaches have been tried and if deemed necessary by a healthcare provider.

3. Farah is viewing an exciting sports match of her favorite team and eating because of nervousness. Her food choice will most likely be based on ___.

A. regional cuisines
B. preferences
C. emotional comfort
D. positive association

Correct answer: C

Rationale: During stressful situations like watching an exciting sports match, individuals often seek emotional comfort through food. This emotional connection can lead Farah to choose foods that provide comfort or familiarity rather than being based on regional cuisines (choice A), general preferences (choice B), or positive associations (choice D). Farah's food choice is likely driven by the need for emotional comfort to alleviate her nervousness, making option C the most suitable answer.

4. How should a healthcare provider respond to a parent concerned about their child's recurrent ear infections?

A. Suggest regular use of over-the-counter ear drops
B. Recommend a thorough evaluation by an ENT specialist
C. Advise on increased antibiotic use
D. Encourage avoiding all physical activities

Correct answer: B

Rationale: When a parent expresses concerns about their child's recurrent ear infections, the best course of action is to recommend a thorough evaluation by an Ear, Nose, and Throat (ENT) specialist. This specialist can conduct a comprehensive assessment to identify the underlying cause of the ear infections and provide appropriate treatment options. Choice A is incorrect because suggesting over-the-counter ear drops without a proper evaluation may not address the root cause of the issue. Choice C is also incorrect as increasing antibiotic use without understanding the specific cause can lead to antibiotic resistance and may not be necessary. Choice D is incorrect as avoiding physical activities is unrelated to addressing recurrent ear infections and is not a recommended approach.

5. Which medication is typically used for long-term control of asthma?

A. Albuterol
B. Theophylline
C. Ipratropium
D. Prednisone

Correct answer: B

Rationale: The correct answer is B, Theophylline. Theophylline is commonly used for long-term control of asthma by relaxing the muscles around the airways to keep them open, making breathing easier. Albuterol (choice A) is a short-acting bronchodilator for quick relief of asthma symptoms, not for long-term control. Ipratropium (choice C) is another short-acting bronchodilator that helps open the airways but is not typically used for long-term control. Prednisone (choice D) is a corticosteroid usually used for short periods to control asthma exacerbations or flare-ups, not as a long-term control medication.