Question

. Fluoride varnish (4.2) In an experiment to measure the effect of fluoride “varnish” on the incidence of tooth cavities, thirty-four 10-year-old girls whose parents volunteered them for the study were randomly assigned to two groups. One group was given fluoride varnish annually for 4 years, along with standard dental hygiene; the other group followed only the standard dental hygiene regimen. The mean number of cavities in the two groups was compared at the end of the 4 years.

a. Are the participants in this experiment subject to the placebo effect? Explain.

b. Describe how you could alter this experiment to make it double-blind.

c. Explain the purpose of the random assignment in this experiment.

Short answer

a. Yes, the placebo effect was used on the trial participants.

b. The experiment has been modified to include a double-blind component.

c. The experiment's random assignment's purpose.

Step-by-step solution

Part (a) Step 1: Given Information

A placebo is a medicine or treatment that has no known side effects.

Part (a) Step 2: According to the given question

A total of 34 ten-year-old girls were randomly assigned to one of two groups after their parents volunteered them for the study.

One group received fluoride varnish once a year for four years, as well as regular dental hygiene.

The other group merely practised regular dental hygiene.

A placebo is a substance that is identical to the treatment given to the treatment group but does not contain any active components.

The placebo effect is an effect created by a placebo that is induced by the patient's belief in the treatment rather than the placebo itself.

In this example, the placebo effect affects the participants in the experiment.

Because there is no alternative for those who use fluoride varnish, the participants will know whether they use it or not.

When compared to youngsters who do not use fluoride varnish, those children pay more attention to taking care of their teeth.

Part (b) Step 1: Given Information

Participants who do not use fluoride varnish should be given a placebo that looks and feels just like fluoride varnish.

The dentist should likewise be kept in the dark about the children's therapy.

Part (b) Step 2: According to the given question

A total of 34 ten-year-old girls were randomly assigned to two groups after their parents volunteered them for the study.

One group received fluoride varnish once a year for four years, as well as regular dental hygiene.

The other group merely followed the standard dental hygiene routine.

The other group merely practised regular dental hygiene.

The personnel who measure or the subjects know which treatment was given in a single-blind experiment.

The subjects and the people who measure don't know which therapy they had in the double-blind experiment.

The participants in the study should not be aware of the treatment they are receiving.

Thus,

Participants who do not use the fluoride varnish should be given a placebo that looks exactly like the fluoride varnish.

We should also not tell the participants (or their parents) which treatment they are getting.

As a result, the study will be double-blind.

The dentist who examines the participant's teeth should not be aware of which treatment is administered.

Otherwise, they might modify the measurements in their favour, either subconsciously or purposefully.

Part (c) Step 1: Given Information

The goal of random assignment is to ensure that the difference in outcomes between the two groups is due to the treatments themselves.

Part (c) Step 2: According to the given question

A total of 34 ten-year-old girls were randomly assigned to one of two groups after their parents volunteered them for the study.

One group received fluoride varnish once a year for four years, as well as regular dental hygiene.

The other group merely practised regular dental hygiene.

The therapy groups are assigned at random to the individuals.

As a result, prior to the treatments, the different groups are as identical as feasible.

We may also be certain that the differences between the two groups following the treatments are due to the therapies themselves.