lecture 9:Placebo Dr.Anna

Dr. Anna Abraham

Treatment Evaluation

& Placebo Effects

Measuring the Impact of Interventions on Outcomes of Interest

BUSINESS

Intervention: Participation in a Leadership Training Program


Impact: Productivity of a Company

LAW

Intervention: Adding hard labour to sentences for minor crimes (stealing)

Impact: Crime rate for minor crimes

Measuring the Impact of Interventions on Outcomes of Interest

MEDICINE

Intervention: New Drug for Coughs


Impact: Cough Symptoms

BEHAVIORAL TRAINING

Intervention: Social training in Autism

Impact: Social Skills

A means to identify cause-and-effect relationships between events and/or behaviors

Follow a set of rules and guidelines that reduce the possibility of errors, biases & chance occurrences

Advantages:

(1) Less error/bias prone than case studies, surveys or observational methods

(2) Most reliable method for identifying cause-and effect relationships

Disadvantages:

(1) Problems in Generalization: Results from one situation may not apply to another situation

Treatment Evaluation:

EXPERIMENT

Are there Differences in the Emotional Reactions of Men and Women when

watching Thrillers versus Romantic Films?

0369

121518

0369

121518

0369

121518


EXPERIMENT

What Else Could Explain The Results?

ACTIVATION OF GENDER STEREOTYPES?

GENDER Do you prefer co-ed or single-

sex floors for flat-sharing?

ETHNICITY How many generations of your family have lived in America?

NEUTRAL How satisfied are you with the university telephone service?

MATH TEST

Source: M. Shih, T. Pittinsky, & N. Ambady (1999), Psychological Science, 10 (1), 80-83.

Stereotype Susceptibility Study on female Asian-American college students


EXPERIMENT


ACTIVATION OF GENDER STEREOTYPES?

Stereotype Susceptibility Study on female Asian-American college students

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FEMALE NEUTRAL ASIAN

Accuracy on Math Test

Source: M. Shih, T. Pittinsky, & N. Ambady (1999), Psychological Science, 10 (1), 80-83.


EXPERIMENT


! EFFECT OF EXPECTATIONS !

Closely related to the concept of

PLACEBO EFFECT

which is also expectancy-based


EXPERIMENT

Is this new cough medicine effective in treating coughs?

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COUGH SYRUP VITAMIN SYRUP

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COUGH SYRUP

VITAMIN SYRUP


EXPERIMENT

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! EFFECT OF EXPECTATIONS !

Closely related to the concept of

PLACEBO EFFECT

which is also expectancy-based


EXPERIMENT

PLACEBO


DEFINITION

Any therapy (or that component of any therapy) that is deliberately used for its non-specific psychological or psychophysiological effect,

OR that is used for its presumed effect on a patient, symptom, or illness,

BUT which, unknown to patient and therapist,

is without specific activity for the condition being treated.”

(Shapiro, 1971, p. 440)

PLACEBO

DEFINITION





(Shapiro, 1971, p. 440)


PLACEBO


SUGAR PILLS (pure placebo)

ANTIBIOTICS (impure placebo)

TREATMENT EFFECT IS NON-SPECIFIC FOR COLDS!

PLACEBO

DEFINITION





(Shapiro, 1971, p. 440)


PLACEBO

DEFINITION





(Shapiro, 1971, p. 440)


Is this new cough medicine effective in treating coughs?

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COUGH SYRUP

VITAMIN SYRUP


Does arthoscopic knee surgery actually relieve knee pain from osteoarthritis?

All Patients: Anesthesia & Incisions

DEBRIDEMENT: Shaved off thin

layers of damaged cartilage

LAVAGE: Flushed out knee

joint & disposed off unhealthy tissue

PLACEBO: No knee surgery was performed


PLACEBO

DEFINITION





(Shapiro, 1971, p. 440)


PLACEBO

DEFINITION





(Shapiro, 1971, p. 440)


PLACEBO


St John’s Wort Bleeding Royal Touch Animal parts

Very long history since the dawn of medicine (Herbs, Preparations, Procedures, Interventions)

PLACEBO



Used to treat a wide variety of disorders (Physical Health & Mental Health)

PLACEBO


Source: M. Choliz & A. Capafons (2012), Theory Psychology, 22, 513.

PLACEBO EFFECT DEMONSTRATED IN Depression Anxiety Phobias Asthma Sedation

Postoperative Pain Ischemic Pain

Chronic Headaches Physiological Arousal

Tobacco Addiction Motor Performance

PLACEBO



PLACEBO EFFECT DEMONSTRATED IN

Depression Anxiety Disorders

ADHD Asthma, Cough Hypertension

Pain Nausea, Swelling

Parkinson’s Disease Irritable Bowel Syndrome

Tobacco Addiction Language & Behavioral Problems

…

PLACEBO




Are not always pharmacologically inert (for example, sugar pills versus antibiotics)

PLACEBO


SUGAR PILLS

Pharmacologically Inert

ANTIBIOTICS

NOT Pharmacologically

Inert

PLACEBO



A PLACEBO MAY BE PHARMACOLOGICALLY INERT BUT

NOT PSYCHOLOGICALLY OR THERAPEUTICALLY INERT

Expectancies Conditioning Personality Motivation Persuasion

Goal Activation

Physician-Patient Interactions Circumstances of Treatment

PLACEBO






Goal Activation


PLACEBO






Goal Activation


MIND-BODY CONNECTION

PLACEBO


CONDITIONING

Unconditioned response

Conditioned response

PLACEBO


PLACEBO: Expectancy vs. Conditioning


Source: Shiv, Carmon & Ariely (2005), Journal of Marketing Research, XLII, 383-393.

PLACEBO






Goal Activation


PLACEBO






Goal Activation



Sources: M. Pecina et al. (2012) Neuropsychopharmacology; Schweinhardt et al. (2009) Journal of Neuroscience

PLACEBO: Personality

When a placebo is administered during a painful experience, altruistic, resilient, and

straightforward people show greater activity in brain regions associated with reward

and are more likely to enjoy pain relief

Thrill-seekers or novelty seeking personality types enjoy a stronger placebo response than

people with quiet or reserved personalities

PLACEBO






Goal Activation


PLACEBO






Goal Activation


PLACEBO





The placebo is non-specific in that it with without specific activity for the condition being treated

PLACEBO


DEPRESSION

75% of the effectiveness of anti-depressant medication

is due to the placebo & other non-specific effects

Difference between drug and placebo not clinically significant except in cases

of very extreme depression

Source: Kirsch I, Deacon BJ, Huedo-Medina TB, Scoboria A, Moore TJ, Johnson BT (2008) PLoS Medicine, 5(2):e45

PLACEBO






Can occur even when a person is aware that they are taking a placebo

PLACEBO


IRRITABLE BOWEL SYNDROME

Source: Kaptchuk TJ, Friedlander E, Kelley JM, Sanchez MN, et al. (2010) PLoS ONE 5(12): e15591.

Enrollment Flowchart Outcomes at the 21-Day Endpoint by Treatment Group

PLACEBO


IRRITABLE BOWEL SYNDROME

Source: Kaptchuk TJ, Friedlander E, Kelley JM, Sanchez MN, et al. (2010) PLoS ONE 5(12): e15591.

Feedback

PLACEBO – GENERAL FEATURES






Can occur even when a person is aware that they are taking a placebo

PLACEBO


“The problem with the placebo effect is that it is regarded by most people as a

nuisance or fake.

But it isn't.

It is a practical and positive effect that acts by catalyzing the self-healing

mechanisms within a patient.”

Richard Tonkin, M.D. (Research Council for

Complementary Medicine)

PLACEBO


PAIN

Inject pain-inducing saline solution into jaw

every four minutes

Provide pain ratings every 15 seconds (0-100)

Pain relieving serum (placebo)

In those who reported less discomfort after the

placebo, body produced endogenous painkilling

endorphins

People who expected to get relief actually produced it!

Source: Zubieta JK, Bueller JA, Jackson LR, Scott DJ, Xu Y, Koeppe RA, Nichols TE, Stohler CS (2005). J Neuroscience 25(34):7754-62

PLACEBO


"Any therapeutic meeting between a conscious patient and a doctor has the potential of

initiating a placebo effect.“

(Asbjorn Hrobartsson)

The word “placebo” comes from the Latin, meaning "I will please"

By the 19th century, it was a medicine given "more to please than to benefit the patient"

(A.K. Shapiro)

PLACEBO


“He cures most successfully in whom the people have the most confidence“

(Galen, AD 129 – AD c. 216)

Physicians should provide patients with hope and comfort and “counteract the depressing

influence of maladies”

(Thomas Percival, 1803)

PLACEBO




Goal Activation




PLACEBO






Goal Activation


PLACEBO


“The life of a sick person can be shortened not only by the acts, but also the words or the manner of a physician. It is therefore, a sacred duty to guard

himself carefully in this respect, and to avoid all things which have a tendency to discourage the patient and depress his spirits.”

(AMA – American Medical Association’s first Code of Ethics in 1847)

“ … deal honestly with patients”

(AMA – American Medical Association’s Code of Ethics in 1980)

PLACEBO


INFORMED CONSENT DOCTRINE

Focus on patient autonomy.

Every person has a right to determine what is done to his own body.

Before providing medical treatment, a physician must explain to the patient the nature and purpose of a proposed treatment, the probable risks and benefits, the probability of success, the availability of reasonable alternative courses of action, and, in many cases,

the risk of refusing treatment.

PLACEBO: INFLUENCES




Goal Activation




NOCEBO


NOCEBO


Negative consequences (harmful, unpleasant, or undesirable)

resulting from the administration of a placebo.

Illustrates the role of patient expectations in perceived side effects

Unwanted side effects (antipsychotic medication, heart disease, even death)

THROUGH EXPERIMENTS

HOW TO ASSESS/CONTROL

FOR PLACEBO EFFECTS?

A means to identify cause-and-effect relationships between events and/or behaviors

Follow a set of rules and guidelines that reduce the possibility of errors, biases & chance occurrences

Advantages:

(1) Less error/bias prone than case studies, surveys or observational methods

(2) Most reliable method for identifying cause-and effect relationships

Disadvantages:

(1) Problems in Generalization: Results from one situation may not apply to another situation

EXPERIMENT

EXPERIMENT:

SCIENTIFIC METHOD

Rule 1: Ask State the question & formulate a hypothesis

Rule 2: Identify how best to test this hypothesis Independent variable (IV): What a researcher manipulates or controls

(TREATMENT) Dependant variable (DV): Participants’ measured behavior

(TREATMENT EFFECT)

Rule 3: Choose Select participants to test the hypothesis

(RANDOM SELECTION)

Rule 4: Assign Participants to different groups

(EXPERIMENTAL group) (CONTROL group)

Rule 5: Manipulate Administer the different treatments to the different groups

Rule 6: Measure Measure how different treatments (IV) affect behavior (DV) => DATA

Rule 7: Analyze Statistical analyses are carried out to determine whether the observed differences in the behaviors (DV) are due to the treatment effect (IV) or due to chance/error

QUESTION: Does Coffee Intake Improve your Ability

to Concentrate on a Difficult Math Problem?

EXPERIMENT:

SCIENTIFIC METHOD


(expectation)

HYPOTHESIS: Coffee Intake Improves the Ability to Concentrate on a Difficult Problem!

(because Caffeine is a stimulant)

EXPERIMENT:

SCIENTIFIC METHOD

TREATMENT or INDEPENDENT VARIABLE (IV):

1. Coffee (with caffeine) EXPERIMENTAL 2. Coffee (caffeine-Free) PLACEBO-CONTROL 3. Water NONPLACEBO-CONTROL


(TREATMENT)

EXPERIMENT:

SCIENTIFIC METHOD

TREATMENT EFFECT or DEPENDENT VARIABLE (DV):

1. Time Taken to complete the Task WHY? Because if you can concentrate better, you should be able to focus on the task better and work faster



(TREATMENT EFFECT)

EXPERIMENT:

SCIENTIFIC METHOD


(RANDOM SELECTION)

Sample characteristics:

1. Total number of participants = 1800 2. Equal number of male & female participants 3. Age = Young adults (18-25 years)

EXPERIMENT:

SCIENTIFIC METHOD



Coffee (with caffeine)

EXPERIMENTAL

Coffee (without caffeine)

PLACEBO-CONTROL

Water (without caffeine)

NON- PLACEBO-CONTROL

EXPERIMENT:

SCIENTIFIC METHOD




EXPERIMENTAL


PLACEBO-CONTROL



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RANDOM ASSIGNMENT

EXPERIMENT:

SCIENTIFIC METHOD


EXPERIMENTAL


PLACEBO-CONTROL



300

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Double - Blind procedure

EXPERIMENT:

SCIENTIFIC METHOD


EXPERIMENTAL


PLACEBO-CONTROL



300

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EXPERIMENT:

SCIENTIFIC METHOD



EXPERIMENTAL


PLACEBO-CONTROL



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RESULT:

Experimental group take LESS time to solve Math

problem than Placebo control group &

Non-Placebo control group

HYPOTHESIS: Coffee Intake Improves the Ability to Concentrate on a

Difficult Problem! (As Caffeine is a stimulant)

EXPERIMENT:

SCIENTIFIC METHOD



EXPERIMENTAL


PLACEBO-CONTROL



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RESULT:

Experimental group take SAME time to solve Math

problem as Placebo-control group

HYPOTHESIS: Coffee Intake Improves the Ability to Concentrate on a

Difficult Problem! (As Caffeine is a stimulant)

EXPERIMENT:

SCIENTIFIC METHOD




(TREATMENT EFFECT)


(RANDOM SELECTION)






Treatment Evaluation: RCT (Randomized Controlled Trial)

The key distinguishing feature of the typical RCT is that study subjects, after assessment of eligibility and recruitment, but before the intervention to be studied begins, are randomly allocated to receive one or other of the alternative treatments under study. Random allocation in real trials is complex, but conceptually, the process is like tossing a coin. After randomization, the two (or more) groups of subjects are followed in exactly the same way, and the only differences between the care they receive, for example, in terms of procedures, tests, outpatient visits, follow-up calls etc. should be those intrinsic to the treatments being compared. The most important advantage of proper randomization is that it minimizes allocation bias, balancing both known and unknown prognostic factors, in the assignment of treatments.

Source: Moher D, Hopewell S, Schulz KF, Montori V, Gøtzsche PC, Devereaux PJ, Elbourne D, Egger M, Altman DG (2010). "CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials". Br Med J 340: c869.

Treatment Evaluation: RCT (Randomized Controlled Trial)

Double - Blind procedure

Dr. Anna Abraham


& Placebo Effects

Documents

lecture 9:Placebo Dr.Anna