L26 - PLACEBO & NOCEBO EFFECTS Flashcards
Definition of placebo effect:
- old
- new
- description of placebo & nocebo
Definition – old
- Placebo = as sham / fake treatment which is not able to determine effect
Definition – new
= effects of psychosocial / ritual context around therapy
Different context lead to different clinical outcomes
- Positive context = placebo effects => easing pain
- Negative context = nocebo effects => worsening pain
Psychobiology: different theories proposed
Expectations
Learning
Psychological
Mindset
Genetics
Health subjects vs patients
Expectation theory: description
Expectation: power of words
= belief or anticipation that treatment lead to specific outcomes, which can trigger real physiological & psychological responses based on beliefs
“This therapy will help you”:
> satisfaction
> compliance
< pain
“I don’t know if this therapy will help you”
< satisfaction
< compliance
> pain
Learning theory: description
Learning: typology
Classical conditioning: neutral stimulus associated with natural response
Observational learning: learning occurs through observation & imitation of others
Associative learning: power of previous experience
If previous negative experience with specific / same technique:
< satisfaction
< compliance
> pain
Social learning: power of social contagion / influence
Patient shares experiences in common spaces & clinician assess & manage +/- social contagion:
< satisfaction
< compliance
> pain
Expectation vs learning
Expectation vs learning: 2 sides of same coin
Previous experiences / learning has greater weight in chronic pain compared to patient’s expectation
Mindset theory: description
Mindset: power of perception of side-effects
If clinician said: “little bit of pain after exercise is ok, positive sign”
> satisfaction
> compliance
< pain
If clinician said: “little bit of pain after exercise is not ok, negative, adverse effects”
< satisfaction
< compliance
> pain
Psychological features:
- optimist
- pessimism
Psychological feature: situational, unstable, changeable traits
Power of yellow flags
Optimist:
- Goal seeking
- Self-efficacy
- Locus of control
- Suggestibility
- Fun seeking
- Sensation seeking
- Neuroticism
Placebo responders
Pessimism:
- Anxiety sensitivity & suggestibility
- Social desirability
- Neuroticism
- Pain catastrophizing
- Blunting behavior
- Frail & submissive personality
- Hypervigilance & fear
- Somatization & amplification
Nocebo responders
Genetic theory
Genetics: polymorphisms
Specific genes influence response to placebo or nocebo effects
Health subject’s vs patients
Health subject’s vs patients: response to context is same
Both patients & health individuals respond similarly to placebo treatments, highlighting importance of context in driving placebo effects
Key points of determinants
Key points
- Different psycho-biological determinants have been proposed
- Expectations & learning processes (associative & social) are main determinants
- Genetic, mindset & psychological traits recently proposed as additional determinants
Mechanisms:
- name
- description with + & - context
- key points
Neurophysiology
Positive & negative contexts determine release of neurotransmitters
Implicated network: DLPC, ACC, PAG, Spine (major areas)
IMAGE
Key points
- Opioids system, endocannabinoid, dopamine, oxytocin / vasopressin implicated in placebo /
positive context
- Cholecystokinin, dopamine / opioid deactivation, cyclooxygenase-prostaglandins implicated in nocebo/negative context
- Despite different areas implicated in placebo / nocebo effects, key regions are: DLPF, ACC,
PAG and dorsal horn
Confounders:
- definition
- other sources of recovery or aggravation
- key points
Confounders = variable influencing relationship between independent variable & dependent variable, leading to misleading conclusions
- Not all patient’s clinical changes due to placebo/nocebo effects
Other sources of recovery or aggravation
- Natural history of disease
- Regression to mean
- Biases by clinicians & patients
- Unidentified co-interventions
- Adverse side-effects in placebo group in RCT
Key points
- Not all clinical improvements / worsening depends on placebo & nocebo effects
- Natural history, regression to mean, co-interventions, prejudices o patient & clinician,
represent cofounders
Contextual factors: outcomes:
- definition
- therapeutic outcomes: 5 domain & description
- clinical relevance
Definition
= context represents whole atmosphere around therapy
Therapeutic outcome – 5 domains
a) Physiotherapist’s features
- Professionalism
- Mindset
- Appearance
- Beliefs & behavior
b) Patient’s features
- Expectation
- Preferences
- Previous experience
- MSK conditions
- Gender
- Age
c) Patient-physiotherapist relationship
- Verbal communication
- Non-verbal communication
d) Treatment features
- Therapeutic touch
- Modality
- Posology
- Marketing
- Clear diagnosis
- Overt therapy
- Observational learning
- Patient-centered approach
- Global process of care
e) Healthcare setting features
- Positive distractors
- Supportive indications
- Environment: Comfort element
- Architecture interior design: Decorations & ornaments
Clinical relevance
Therapeutic outcome = specific treatment (active & biological) + psychosocial context
Greater effect on illness component (subjective outcomes)
Minor effect on disease component (objective outcomes)
Illness: person’s subjective experience of symptoms. What patient brings to
doctor
Disease: underlying pathology, biologically defined, practitioner’s perspective.
Illness seen in terms of theory of disorder
Sickness: social & cultural conceptions of condition: cultural beliefs & reactions such as fear or rejection, these affect how patient reacts. Also covers what is considered disorders suitable for medical
treatment
30% of outcome it has historically been associated with context
Contextual effect varies from large to small due to characteristics of patient, practitioner, condition,
intervention & metric used
Prefrontal lobe injury Alzheimer’s disease
Key points on outcomes
Key points
- Context influences all clinical conditions with different weight
- In “non-lifesaving” pathologies greater effect, while in “Lifesaving” pathologies a limited effect
- Subjective outcomes more influenced by context compared to objective outcomes
Contextual factors: clinical reasoning:
- patient’s role: description, different needs
Is a non-linear adaptative complex system
Creates perceptions of symptoms through context
Has perceptions +/- based on congruence / incongruence of context
- Previous + patient’s expectations
- Interaction with positive context
- Positive final healthcare experience
> Congruence = placebo effects
- Previous + patient’s expectation
- Integration with negative context
- Negative final healthcare experience
< Congruence = nocebo effects
Seeks answers to cognitive & emotional needs in physiotherapy
TABLE
Contextual factors: clinical reasoning:
- clinician’s role: patient improvement, aggravation, Dunning-Kruger effect & description of situations
Clinician’s role
Should be aware of personal biases, “limits of profession”
Patient’s improvement depends on:
- Skills as clinicians
- Training course carried out
- Specificity of therapy
- New machine purchased
Patient’s aggravation depends on:
- Discrepancy of eligibility for practice
- Presence of psychological problem
- Delivery of non-specific technique
- Lack of commitment to follow directions
Dunning-Kruger effect
IMAGE
Modifies incongruence of context to influence patient’s perceptions
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Keeps “gaze” turned to patients, putting himself in their shoes
Thins in parallel about “what” to ho & “how” to do it
Can’t afford to lose patient for using negative contexts
Contextual factors: clinical reasoning: role of context
Always interacts with patients, when seeking care
Receiving therapy & meeting therapist are
contextual factors
Acts with different weights
Can change trajectory of physiotherapy intervention
Offers meaning, triggering psycho-neuro-immuno-endocrine effects
IMAGE
Contextual factors: clinical reasoning: role of treatments
Represent modulatory inputs
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Are strongly influenced by context (manual therapy, needles & modalities, therapeutic exercise, pharmacological treatment, psychotherapy, surgery)
Is changed during COVID-19 pandemic
- Telerehabilitation
- Personal protective equipment
Contextual factors: clinical reasoning: role of researcher
Should challenge creation of placebo-control RCT in MSK care
- Placebo treatments do not exist: complex multi-sensory intervention & impossibility to
differentiate specific component from contextual one
Applied same technique, enriched therapeutic context VS neutral or poor therapeutic context
Key points of clinical reasoning
Key points
- Patient is a complex system influenced by context
- As clinicians we can manage context aimed to triggers placebo effects & to avoid nocebo
effects
- Using context patient can predict healthcare outcome
- Physiotherapy treatment (manual therapy, exercise…) represent input able to modulate
system
Contextual factors: tip & tricks: patient / clinician relationship
- element
- Clinician’s dynamic elements
- Problems of poor communication with patients
- what happens in practice
- reciprocity of language
- touch
- management of unexpected
Patient – clinician relationship
Elements
- Verbal content
- Tone of voice
- Body language
Clinician’s dynamic elements
Evolutionary function: happiness, confusion, sadness, surprise, anger, excitement
Problems of poor communication with patients
- Conduct shorter interviews
- Make fewer statements for managing course of interviews
- Make fewer statement encouraging patients to elaborate on thoughts or offer opinions
- Make fewer statements to ensure patients understand what is said
- Less humor & laughter during interviews
70-80% of legal procedures
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What happens in clinical practice
- Average first interruption after 22 sec
- Patient’s memory of first visit highly variable (17-60% after visit & 12% after month)
- Clinician speaks 2 times more than patient
- Technical content superior to emotional one
Relation styles: communication depends on patient’s needs:
- Patient: cognitive needs => Clinician: competence
- Patient: emotional needs => Clinician: humanity
Reciprocity of language
If use medical language, add explanation (from nocebo to placebo)
Use images & metaphors (placebo)
Touch
Different types but the more occurrence is assistive touch
Management of unexpected: rupture & repair
- Disagreement on goals
- Disagreement on tasks
- Empathic failure within emotional bond
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Contextual factors: tip & tricks: patient / clinician features
Concept of professionalism = multi-dimensional
Only have first chance to make good first impression
Direct impact on patients’ outcomes
Private settings:
> professional
< professional & favorite
As number of visits increases, habitus has lower weight
Clinician’s way of thinking impacts patient’s outcome
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Contextual factors: tip & tricks: patient / patient’s features:
- pre treatment screening
- Strategies for managing patient’s point of view
Investigate patients’ point of view & align with them
Pre-treatment screening
Internal model:
Prior high precision
- Strong expectations
- Strong priors
Prior low precision
- Weak expectations
- Weak priors
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Strategies for managing patient’s point of view
Pre-treatment – Cognition → post-treatment
Pre-treatment – Disconfirmation / exposure → post-treatment
Pain → No pain
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Contextual factors: tip & tricks: features of treatment
Features of treatment
History taking, physical examination = therapy themselves
Open administration is better than covert
Different treatments have different rituality
Rituality: emphasizing it during therapy administration = key
Interaction among patients on common areas:
- Be aware of possible interactions among patients
- In waiting room or in gym room
Contextual factors: tip & tricks: features of healthcare setting:
- description
- symbols of care
- personal elements
Feature of healthcare setting
Adequate health setting influences recovery in operated patients
- Examples of healthcare settings: number of days of hospitalization, number of doses of
treatment, view from room stay
Adequate health setting influences patients’ outcome
< pain
> quality of sleep
< stress, anxiety, fear & depression
< days of hospitalization, perception of privacy
> spatial orientation
> communication, social support
> satisfaction
Symbols of care: useful to define status of professional
- Diploma, certificate
- Posters
- Skeleton
- Instruments
- Books…
Personal elements: useful to define person behind professional
- Images of trips
- Design
- Clock
- Books
- Aquarium …
Elements not always changeable, but to be considered for clinical impact
Risk of extreme (nocebo effect):
- Effect excessively cold & detached
- Unprofessional & irrelevant
Finding balance guarantees (placebo effect):
- More adequate health setting
- Equilibrium between professionalism & humanity
Contextual factors: ethics: deontology principles
- description
- principle of ethics
- key points
Deontological principles
Managing patient’s perspective, we need to respect bioethical principles
Principles of ethics:
- Autonomy
- Justice
- Beneficence
- Nonmaleficence
Placebo / nocebo effects & context follow evidence-based practice
TABLE
Use of context factors = opportunity to enrich EBM therapies
TABLE
Key points
- Placebo, nocebo & contextual factors should not justify pseudo-science
- As healthcare providers, we need to base practice on ethical & deontological principles
- There is need to balance external evidence with patients’ expectation, considering clinical
expertise
Conclusion: clinical consideration & resume of lesson
Clinical consideration
Don’t focus on finger, look at moon
- Confounders (natural history of disease, regression towards mean)
- Contextual factors (clinical ritual, expectations, language…)
- Specificity of treatment
Resume of lesson
- Therapeutic result more than sum of individual parts
- Placebo & nocebo effects affect physiotherapy outcomes
- Moving beyond technique broadens perspective
- Challenging preconceptions is tiring, but necessary to grow
- Stimulating placebo effect is good, but avoiding nocebo effect is key
- In practice, think about what to do but also on how to do it
