placebo
Statistics
Psychology
Examples of placebo in the following topics:
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The Clofibrate Trial
- Placebos are most commonly used in blinded trials, where subjects do not know whether they are receiving real or placebo treatment.
- The purpose of the placebo group is to account for the placebo effect -- that is, effects from treatment that do not depend on the treatment itself.
- Those in the placebo group who adhered to the placebo treatment (took the placebo regularly as instructed) showed nearly half the mortality rate as those who were not adherent.
- This apparent placebo effect may have occurred because:
- Adhering to the protocol had a psychological effect, i.e. genuine placebo effect.
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Exercises
- In the ADHD case study, transform the data in the placebo condition (D0) with λ's of .5, 0, -.5, and -1.
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Introducing observational studies and experiments
- For example, each heart attack patient in the drug trial could be randomly assigned, perhaps by flipping a coin, into one of two groups: the first group receives a placebo (fake treatment) and the second group receives the drug.
- See the case study inSection 1.1 for another example of an experiment, though that study did not employ a placebo.
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Experiments exercises
- A quarter of the patients were assigned a placebo, and the rest were evenly divided between 1g Vitamin C, 3g Vitamin C, or 3g Vitamin C plus additives to be taken at onset of a cold for the following two days.
- No significant differences were observed in any measure of cold duration or severity between the four medication groups, and the placebo group had the shortest duration of symptoms.
- One group was given 25 grams of chia seeds twice a day, and the other was given a placebo.
- Explanatory: Treatment, with 4 levels: placebo, 1g, 3g, 3g with additives.
- However, we must consider that a placebo effect is possible.
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Case study exercises
- To determine whether acupuncture relieves migraine pain, researchers conducted a randomized controlled study where 89 females diagnosed with migraine headaches were randomly assigned to one of two groups: treatment or control.43 patients in the treatment group received acupuncture that is specifically designed to treat migraines. 46 patients in the control group received placebo acupuncture (needle insertion at non-acupoint locations).
- Study participants received either a 10-day course of amoxicillin (an antibiotic) or a placebo similar in appearance and taste.
- The placebo consisted of symptomatic treatments such as acetaminophen, nasal decongestants, etc.
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Case Studies
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Exercises
- A study comparing a drug with a placebo on the amount of pain relief.
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Alternatives to Traditional Health Care
- Its academic proponents sometimes recommend misleading patients by using known placebo treatments in order to achieve a placebo effect.
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The Salk Vaccine Field Trial
- The Salk polio vaccine field trial incorporated a double blind placebo control methodolgy to determine the effectiveness of the vaccine.
- By the conclusion of the study, roughly 440,000 received one or more injections of the vaccine, about 210,000 children received a placebo, consisting of harmless culture media, and 1.2 million children received no vaccination and served as a control group, who would then be observed to see if any contracted polio.
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Introduction to Biomedical Therapies
- Placebo-controlled randomized clinical trials, using strict exclusionary criteria when selecting subjects, have traditionally been used to study a psychiatric medication's efficacy (i.e., the ability of the medication to treat the condition better than placebo under controlled conditions).
- For example, studies comparing an antidepressant to a placebo may use an eight-week double-blind parallel design and include subjects with major depression, but without any other medical or psychiatric comorbidities.