This document discusses using anchoring vignettes to address reporting heterogeneity in patient-reported outcome measures (PROMs) like the EQ-5D-5L. It conducted two stages of research: 1) a qualitative study that found rating health vignettes for the EQ-5D-5L was feasible but response consistency needed improvement, and 2) a quantitative study using surveys of 4000 Australians that developed two health vignettes and used hierarchical ordered probit modeling to test for differential item functioning across age, gender, education and other groups when rating health status. The research aims to determine if anchoring vignettes can identify reporting heterogeneity in the EQ-5D-5L and help make more valid cross-group
OHE’s Professor Nancy Devlin has researched, written and spoken widely on the use of the EQ-5D, and related measures, both in her capacity as the Director of Research at the OHE and as Chair of the Executive Committee of the EuroQol Group.
In May, Nancy was invited to participate in the “Workshop on measuring patient-reported outcomes using the EQ-5D”, which was organised by the Swedish National Board of Health and Welfare in collaboration with the EuroQol Group. The workshop brought together policy makers and researchers in Sweden interested in measuring patients’ health outcomes.
Sweden has included the EQ-5D in some of its quality registries and in population health surveys for many years. The Swedish National Board of Health and Welfare now is exploring whether and how to extend use of patient reported outcomes measures in the health care system, including the EQ-5D, to both monitor the quality of providers and services and to facilitate health technology appraisal.
Nancy’s talk, shown below, introduced the EQ-5D instrument; discussed how data from it can be analysed; identified some of the challenges in analysis; and commented on the future of outcomes measurement.
OHE’s Professor Nancy Devlin has researched, written and spoken widely on the use of the EQ-5D, and related measures, both in her capacity as the Director of Research at the OHE and as Chair of the Executive Committee of the EuroQol Group.
In May, Nancy was invited to participate in the “Workshop on measuring patient-reported outcomes using the EQ-5D”, which was organised by the Swedish National Board of Health and Welfare in collaboration with the EuroQol Group. The workshop brought together policy makers and researchers in Sweden interested in measuring patients’ health outcomes.
Sweden has included the EQ-5D in some of its quality registries and in population health surveys for many years. The Swedish National Board of Health and Welfare now is exploring whether and how to extend use of patient reported outcomes measures in the health care system, including the EQ-5D, to both monitor the quality of providers and services and to facilitate health technology appraisal.
Nancy’s talk, shown below, introduced the EQ-5D instrument; discussed how data from it can be analysed; identified some of the challenges in analysis; and commented on the future of outcomes measurement.
Journal Club - Mortality after Fluid Bolus in African Children with Severe In...Farooq Khan
Critical Appraisal of:
Maitland K, Kiguli S, Opoka RO, et al. Mortality after fluid bolus in African children with severe infection. N Engl J Med 2011;364:2483-95
Research in International Emergency Medicine: Scope, Impact and Challenges
EBM Topic: Subgroup Analysis
The scientific study of methods to promote the systematic uptake of research findings and other evidence-based practices into routine practice and hence improve the quality and effectiveness of health services
Please join CPSI as we conclude our Human Factors webinar series with our final presentation Collaborative "Spaces" and Health Information Technology Design
CURRICULUM ON RESIDENCY PROGRAM FOR FCPS MOLECULAR PATHOLOGYJibran Mohsin
CURRICULUM ON RESIDENCY PROGRAM FOR FCPS MOLECULAR PATHOLOGY (Advanced Level Course on Curriculum Development in Health Professions Education, Department for Educational Development, The Aga Khan University)
Adjusting for Differential Item Functioning in the EQ-5D-5L Using Externally-...Office of Health Economics
Paula and Rachel's presentation on adjusting for differential item functioning in the EQ-5Q-5L using externally-collected vignettes given at the 2017 iHEA World Conference in Boston.
Journal Club - Mortality after Fluid Bolus in African Children with Severe In...Farooq Khan
Critical Appraisal of:
Maitland K, Kiguli S, Opoka RO, et al. Mortality after fluid bolus in African children with severe infection. N Engl J Med 2011;364:2483-95
Research in International Emergency Medicine: Scope, Impact and Challenges
EBM Topic: Subgroup Analysis
The scientific study of methods to promote the systematic uptake of research findings and other evidence-based practices into routine practice and hence improve the quality and effectiveness of health services
Please join CPSI as we conclude our Human Factors webinar series with our final presentation Collaborative "Spaces" and Health Information Technology Design
CURRICULUM ON RESIDENCY PROGRAM FOR FCPS MOLECULAR PATHOLOGYJibran Mohsin
CURRICULUM ON RESIDENCY PROGRAM FOR FCPS MOLECULAR PATHOLOGY (Advanced Level Course on Curriculum Development in Health Professions Education, Department for Educational Development, The Aga Khan University)
Adjusting for Differential Item Functioning in the EQ-5D-5L Using Externally-...Office of Health Economics
Paula and Rachel's presentation on adjusting for differential item functioning in the EQ-5Q-5L using externally-collected vignettes given at the 2017 iHEA World Conference in Boston.
This poster, presented at ISPOR 6th Asia-Pacific Conference in September 2014, reports on an investigation into the use of time trade off and discrete choice experiments to value health states. No EQ-5D-5L value sets are available now to guide health care decision making in the UAE, despite increasing interest in using patient-preference data in decisions about drug coverage.
This study, based on 320 interviews, finds that religious and spiritual beliefs made it difficult to explain the 'worse than death' (WTD) concept used in TTO and that fewer respondent than in other countries rated health states as WTD. The importance of dimensions also differed, with the majority of respondents considering mobility to be most important and anxiety/depression least important.
The authors conclude that, for TTO, adaptation of methods may be required. No issues were encountered using DCE.
For additional information, contact Koonal Shah at OHE.
Geoff Norman, PhD
McMaster University
Presented at Perspectives in Competency Assessment
A Symposium by Touchstone Institute
www.touchstoneinstitute.ca
The C. Everett Koop National Health Award recognizes population health promotion and improvement programs. Each year, awards are presented by The Health Project’s leadership to winning organizations as part of the annual HERO Forum each fall. This Thursday Ron Goetzel joins us for an update on the C. Everett Koop National Health Award with information on criteria and how to apply.
Chapter 2
Study Designs
Learning Objectives
• List and define the components of a good
study design
• Compare and contrast observational and
experimental study designs
• Summarize the advantages and disadvantages
of alternative study designs
Learning Objectives
• Describe the key features of a randomized
controlled trial
• Identify the study designs used in public health
and medical studies
Study Designs
• Observational Studies
– Case-series study
– Cross-sectional (prevalence) survey
– Case-control study
– Cohort study
• Experimental Studies
– Randomized Controlled (Clinical) Trial
Inferences
• Observational studies – inferences limited to descriptions
and associations; with carefully designed analysis can
make stronger inferences (statistical adjustment)
• Experimental studies – cause and effect
In ALL studies – need careful definition of disease
(outcome) and exposure (risk factor)
Which Design is Best
• Depends on the study question
• What is current knowledge on topic
• How common is disease (and risk factors)
• How long would study take, what are costs
• Ethical issues
Case Report/Case Series
• Observational study
• Case report: Detailed report of specific
features of case
• Case series: Systematic review of common
features of a small number of cases
• Advantage: Cost-efficient
• Disadvantages: No comparison group, no
specific research question
Case-Series
• Simplest design – description of interesting
observations in a small number of individuals
• Usually case-series do not involve control patients
(i.e., patients free of disease)
• Usually lead to generation of hypotheses for more
formal testing
• Criticisms: not planned – no research hypotheses
Case-Series
• Gottleib (1981) studied 5 young homosexual
men with rare form of pneumonia and other
unusual infections
• Initial report was followed by more series (26
cases in NY and CA; “cluster” in southern CA;
34 cases among Haitians, etc.)
• Condition termed AIDS in 1982
Cross-Sectional Survey
• Observational study conducted at a point in
time
• Advantages: Cost-efficient, easy to implement,
ethical
• Disadvantages: No temporal information, non-
response bias
Cross-Sectional Survey
• Is there an association between diabetes and
cardiovascular disease (CVD)?
Patients
with
Diabetes
Patients without
Diabetes
Patients with
CVD
Prospective Cohort Study
• Observational study involving a group (cohort)
of individuals who meet inclusion criteria
followed prospectively in time for risk factor
and outcome information
• Advantages: Can assess temporal relationships
• Disadvantages: Need large numbers for rare
outcomes, confounding
Cohort Study
• Is there an association between hypertension and
cardiovascular disease?
CVD
Hypertension
No CVD
Cohort
CVD
No Hypertension
No CVD
Study Start Time
Cohort Studies
• Identify a group of individuals that meet
inclusion crit ...
Valuing the EQ-5D-Y Using a Discrete Choice Experiment: Do Adult and Adolesce...Office of Health Economics
Slides from a presentation OHE's Koonal Shah gave at the PROMs research conference on June 20th, 2018. The subject of the presentation was valuing the EQ-5D-Y using a discrete choice experiment: do adult and adolescent preferences differ?
Do height and BMI affect human capital formation? Natural experimental evidence from DNA. CHE seminar presentation by Neil Davies, University of Bristol 12 June 2020
Healthy Minds: A Randomised Controlled Trial to Evaluate PHSE Curriculum Deve...cheweb1
CHE Seminar presentation 16 January 2020, Alistair McGuire, Department of Health Policy, LSE. Evaluating the Healthy Minds program: The impact on adolescent’s health related quality of life of a change in a school curriculum
Baker what to do when people disagree che york seminar jan 2019 v2cheweb1
Public values, plurality and health care resource allocation: What should we do when people disagree? (..and should economists care about reasons as well as choices?) CHE Seminar 21 January 2019
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
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APPLICATION OF PHARMACOKINETICS : TARGETED DRUG DELIVERY SYSTEMS By - AKANKSHA ASHTANKAR
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
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This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
ABDOMINAL TRAUMA in pediatrics part one.drhasanrajab
Abdominal trauma in pediatrics refers to injuries or damage to the abdominal organs in children. It can occur due to various causes such as falls, motor vehicle accidents, sports-related injuries, and physical abuse. Children are more vulnerable to abdominal trauma due to their unique anatomical and physiological characteristics. Signs and symptoms include abdominal pain, tenderness, distension, vomiting, and signs of shock. Diagnosis involves physical examination, imaging studies, and laboratory tests. Management depends on the severity and may involve conservative treatment or surgical intervention. Prevention is crucial in reducing the incidence of abdominal trauma in children.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
The application of anchoring vignettes to the EQ-5D-5L: a possible solution to reporting heterogeneity in PROMs6
1. Paula Lorgelly
Deputy Director, OHE
Visiting Professor, Division of Cancer Studies, Kings College London
6th October 2016
The application of anchoring
vignettes to the EQ-5D-5L:
a possible solution to reporting
heterogeneity in PROMs
2. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Acknowledgments
• Australian Research Council Discovery Project Grant
(DP110101426)
• Investigators: Paula Lorgelly, Bruce Hollingsworth, Mark Harris,
Nigel Rice, John Wildman, William Greene
• Researchers: Rachel Knott, Nicole Black (Au)
• BankWest Curtin Economics Centre Research Grants Program
• Mark Harris, Nigel Rice, Paula Lorgelly, Rachel Knott
• Faculty of Business and Economics Research Grant Scheme
• Paula Lorgelly, Rachel Knott, Mark Harris
3. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Background
• Individual and household surveys often rely on self-reported
measures of health
• In general, would you say your health is: excellent, very good,
good, fair or poor?
• Analyses using measures of self-reported health (SRH) rely on
the measure being an accurate reflection of the true health of the
groups or individuals concerned
• But responses to questions on subjective scales will be inaccurate
if groups of individuals systematically differ in their use and/or
interpretation of the response categories
• Systematic variation in the use of response categories is known
as reporting heterogeneity or response scale heterogeneity or
differential item functioning (DIF)
4. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
EQ-5D
• The EQ-5D is the most commonly used instrument for measuring
preference-based health-related quality of life (HRQoL)
• The responses to the five health domains can be used
descriptively as health profiles (12112) or converted to a
preference-weighted summary index which reflects health-related
utility (where 0 is dead and 1 is full health), thus can be used to
estimate QALYs
• Most commonly used in economic evaluations, but the EQ-5D is
increasingly being used as a measure of population health status
and is included in a number of population health surveys
• When used to measure and compare health profiles or utilities
across sub-groups of the population, the results will be
misleading if groups systematically differ in use of response
categories
• Could the EQ-5D suffer from DIF like other SRH measures?
5. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
5
6. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Differential Item Functioning
τ4
τ3
τ2
τ1
No problems
Slight problems
Moderate problems
Severe problems
Unable to walk
Group 2
Underlyinglatenthealthscaleformobility
τ4
τ3
τ2
τ1
No problems
Slight problems
Moderate problems
Severe problems
Unable to walk
Group 1High mobility
Low mobility
Group 2’s
mean health
Group 1’s
mean health
7. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Programme of research
• ARC funded project (starting 2011) assessing reporting
behaviour/heterogeneity and it’s consequences
• Focus on SRH (generic likert scale) in panel surveys
• Addition of primary research looking at relatively new
phenomenon of anchoring vignettes
• Limited research considering DIF in the EQ-5D, none using
anchoring vignette technique
• Programme of research
• Necessary to design vignettes, given identifying assumptions
• Explore feasibility of eliciting responses
• Robustly test if can be used to adjust for DIF
• Consider broader applications
8. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Anchoring vignettes
• In order to obtain any meaningful comparison between the health
of groups 1 and 2 it is essential to adjust for DIF
• Anchoring vignettes (King et al. 2004) can be used to adjust for
DIF
• Previously been used to address DIF in political efficacy,
job/income/life satisfaction, general/specific health measures
• Vignette - a brief health description of a hypothetical individual
• Respondents are asked to rate the health state described by the
vignette using the same ordered categories they use to rate their
own health
• Since the actual level of health of the people in the vignettes is
the same for all respondents, the variation in ratings can be used
to identify and correct for DIF
9. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Anchoring vignettes
• Example of a vignette for the mobility domain:
Belinda walks for one or two kilometres and climbs three flights
of stairs every day without tiring.
Select the one option that best describes Belinda’s mobility:
She has no problems with walking around
She has slight problems with walking around
She has moderate problems with walking around
She has severe problems with walking around
She is unable to walk around
10. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Anchoring vignettes
• Typically, a series of vignettes are presented for each health
construct of interest, at varying levels of severity
• Suppose we give groups 1 and 2 two vignettes to rate, of
differing severity:
• Vignette 1 – limited problems in walking around
• Vignette 2 – more problems in walking around
11. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Anchoring vignettes
τ4
τ3
τ2
τ1
No problems
Slight problems
Moderate problems
Severe problems
Unable to walk
Group 2
Underlyinglatenthealthscaleformobility
Vignette 2
Vignette 1
High mobility
Low mobility
τ4
τ3
τ2
τ1
No problems
Slight problems
Moderate problems
Severe problems
Unable to walk
Group 1
12. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Necessary assumptions
• Vignette equivalence (VE) holds if all respondents interpret the
health states described by the vignettes in the same way and on
the same uni-dimensional scale, aside from random error.
• VE is demonstrated in the example above by the horizontal
dotted lines
• Response consistency (RC) is where respondents rate the health
of the hypothetical people described in the vignettes in the same
way or using the same underlying scale that they would rate their
own health.
• RC would be violated if, for example, respondents rated the
health described by the vignettes either more or less harshly
than they did their own health
13. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 1: Qualitative assessment of RC
• Initial ARC study question
• Research questions:
• Is the rating of vignettes for the EQ5D-5L feasible?
• How do the vignette ratings compare by version?
• Informal test for VE – is the ordering of vignettes consistent
with global ordering?
• Understand thought process when rating vignettes – do
respondents rate hypothetical individuals in the same way as
themselves? Does RC hold? (qualitative perspective).
14. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Methods – vignette development
• Gary King has a library of vignettes
http://gking.harvard.edu/vign/eg/
• Used these where possible and amended according to EQ-5D
attributes mobility, self care, usual activities, pain,
anxiety/depression
• Version A: 15 vignettes - single health dimensions. Asks EQ-5D-
5L by health dimension
• Version B: 3 vignettes - combined health state. Asks EQ-5D-5L as
a whole including the VAS
• Respondents asked to rate the health of people in the vignettes
before rating their own health to help with priming
• Vignette names were gender specific
• Respondents were instructed to assume the hypothetical people
were of the same age and background as themselves
15. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Pluralistic research design
• Online survey: socio-demographic questions, long term illnesses,
health seeking behaviour, objective health measures, vignettes
and EQ-5D-5L (+ SAH).
• Randomisation of survey version (A or B)
• Data collection: April to May 2012
• Phase 1: Online survey + face-to-face interview
• Interview to assess survey (clarity of instructions, wording &
formatting) and feasibility of vignette task (clarity of the
vignettes, level of concentration required, and thought
processes).
• Phase 2: Online survey only
• Additional questions on thoughts during vignette rating task
• Subjects: staff, students and people from a database of past
research participants recruited through Monash University online
newsletter and emails.
16. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Results – feasibility
• Interview feedback:
• Survey was straight forward and easy
• Vignettes were easy to understand and the descriptions
seemed real and imaginable.
• 3 younger respondents (aged 18-24) found some scenarios
difficult to imagine for someone their age.
• Version A: one respondent noted the difficulty in rating a
person’s health “…without any other background or other
knowledge of other aspects of their health” (Male, 30-34).
– Highlights trade-off between simplicity of vignettes and lack
of context in a single health dimension description.
• Version B was equally easy to understand as A
• But, version B required more concentration than A
17. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Response consistency
• Did you assume the people in the vignettes were of the same age
and background as yourself?
• Total sample, yes = 69%
• Interview: If no, why?
• “When I read someone more disabled than myself I thought
they were possibly older and if less disabled, possibly
younger”. (Male, 55-59, VA).
• “Most of them seemed older than me. I probably don’t see
many people with those symptoms my age”. (Male, 18-24,
VA)
18. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Response consistency
• Did you imagine yourself in the health state of the people in the
vignettes (at least for some of them)?
• Online only: yes = 77%
• Many in interview also demonstrated this. For example:
• “I pictured myself in that position. It’s easier to judge whether
something is bad or not if it happens to you.” (Male, 18-24,
VA).
• Others in interview took an external view. For example:
• “I didn’t think of myself as them – I thought they were
another person. I rated myself quite separately from the
vignettes” (Female, 25-29, VB)
• “I was trying to think of a view that a medical or paramedic
person would put on it.” (Male, 70+, VA)
19. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Response consistency
• Did you rate your own health on the same scale as the
hypothetical individuals?
• Online only: 39% strongly agree; 39% somewhat agree; 15%
disagree; 6% unsure
• More people in version B strongly agree (50%) than in version A
(29%).
• Suggests describing vignette as a whole health state rather than
as independent health dimensions does a better job at
encouraging response consistency.
• Combined responses (interview and online only) suggest 37%
demonstrated response consistency (28% for version A, 46% for
version B).
20. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 1: Summary
• Evidence that vignettes for the EQ-5D-5L are feasible
• Suggested improvements required in the wording in order to
improve response consistency
• Health states age neutral
• … imagine yourself …
• Several avenues to explore in future work
• Au and Lorgelly (2014) Anchoring vignettes for health
comparisons: an analysis of response consistency. QoLR.
• Knott et al (2016) Response scale heterogeneity in the EQ-5D.
Health Economics
21. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 2: Quantitative exploration
• Second ARC study question plus BankWest study
• Research questions:
• Can the anchoring vignette approach be used to identify DIF in
the EQ-5D-5L?
• Does it pass ‘strong’ tests for RC and VE?
• What is the impact of DIF on inter-group comparisons?
22. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Data
• Two online surveys of a sample of representative Australian
residents, recruited via a survey panel company (April 2014 and
Aug/Sept 2015)
• First survey compared versions A and B (and priming effect),
second only used version B, analysis focuses on version B
vignettes, of which their were two
• Total n=4,095
23. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Vignette 1
• REBECCA/ROB is able to walk distances of up to 500 metres
without any problems but feels puffed and tired after walking one
kilometre or walking up more than one flight of stairs. She/he is
able to wash, dress and groom her/himself, but it requires some
effort due to an injury from an accident one year ago. Her/his
injury causes her/him to stay home from work or social activities
about once a month. Rebecca/Rob feels some stiffness and pain
in her/his right shoulder most days however her/his symptoms
are usually relieved with low doses of medication, stretching and
massage. She/he feels happy and enjoys things like hobbies or
social activities around half of the time. The rest of the time
she/he worries about the future and feels depressed a couple of
days a month.
24. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Vignette 2
• CHRISTINE/CHRIS is suffering from an injury which causes
her/him a considerable amount of pain. She/he can walk up to a
distance of 50 metres without any assistance, but struggles to
walk up and down stairs. She/he can wash her/his face and comb
her/his hair, but has difficulty washing her/his whole body
without help. She/he needs assistance with putting clothes on the
lower half of her/his body. Since having the injury Christine/Chris
can no longer cook or clean the house her/himself, and needs
someone to do the grocery shopping for her/him. The injury has
caused her/him to experience back pain every day and she/he is
unable to stand or sit for more than half an hour at a time.
She/he is depressed nearly every day and feels hopeless. She/he
also has a low self-esteem and feels that she/he has become a
burden.
25. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Data
• Standard socio-demographic questions, self reports of own health
(EQ-5D-5L and SRH), vignettes, additional health questions
• First survey included ‘objective’ health measures to test RC
• Considered heterogeneity in following groups
• Age, gender, education and country of birth
26. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Econometric Analysis
• Hierarchical ordered probit (HOPIT) model
• Extension of OP but allows for variation in the inter-category
thresholds by modelling them as a function of covariates
• We estimated five separate HOPITs for each domain of the EQ-
5D-5L
• DIF is tested for using LR that restrict the threshold covariates to
be zero
• Impact of DIF on EQ-5D-5L indices assessed by simulating data
given distribution of latent health using the estimated parameters
of the mean function of the HOPIT and the characteristics of each
individual, apply the predicted thresholds at sample means of the
covariates
• EQ-5D-5L values from Australian DCE (Norman et al, 2013)
27. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Testing the assumptions
• Bago d’Uva et al (2011) developed tests for VE and RC
• RC test based on objective measures
• Inter-category thresholds should be the same for across the
health and the vignette equations
• VE tests that no systematic difference in perceptions of the health
states of the vignette persons
• Interactions between individual characteristics and vignette
severity (for all but one vignette)
28. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Results regarding assumptions
Degrees of
freedom
χ2
test statistic p-value
Response consistency
Mobility 13 15.12 0.300
Self-care 13 18.31 0.146
Usual activities 13 8.14 0.835
Pain/discomfort 13 18.86 0.127
Anxiety/depression 13 19.44 0.110
Vignette equivalence
Mobility 13 100.06 <0.001
Self-care 13 178.69 <0.001
Usual activities 13 170.03 <0.001
Pain/discomfort 13 241.63 <0.001
Anxiety/depression 13 172.44 <0.001
29. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Vignette equivalence – age groups
Degrees of freedom χ2
test statistic p-value
Age 20-34
Mobility 8 21.785 0.005
Self-care 8 65.791 <0.001
Usual activities 8 54.208 <0.001
Pain/discomfort 8 68.995 <0.001
Anxiety/depression 8 38.895 <0.001
Age 35-44
Mobility 8 28.017 <0.001
Self-care 8 75.826 <0.001
Usual activities 8 56.664 <0.001
Pain/discomfort 8 79.472 <0.001
Anxiety/depression 8 45.601 <0.001
Age 45-54
Mobility 8 67.563 <0.001
Self-care 8 110.842 <0.001
Usual activities 8 93.543 <0.001
Pain/discomfort 8 129.923 <0.001
Anxiety/depression 8 82.278 <0.001
Age 55-65
Mobility 8 8.296 0.600
Self-care 8 9.427 0.492
Usual activities 8 11.675 0.307
Pain/discomfort 8 15.076 0.129
Anxiety/depression 8 24.061 0.007
30. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Evidence of DIF for 55-65 (N=914)
Mobility Self-care
Usual
activities
Pain/
discomfort
Anxiety/
depression
LR test statistic 94.82 57.71 64.73 74.89 74.57
p-value 0.000 0.043 0.008 0.001 0.001
Degrees of freedom 40 40 40 40 40
31. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Mobility Self care
Usual
activities
Pain/
Discomfort
Anxiety/
Depression
Female -0.165* -0.005 0.059 0.131*** 0.035
(0.087) (0.052) (0.046) (0.050) (0.047)
Education (base category low)
Medium -0.128 -0.088 0.014 -0.109* 0.047
(0.095) (0.061) (0.054) (0.057) (0.055)
High -0.251** -0.168** -0.073 -0.142** -0.03
(0.107) (0.067) (0.057) (0.061) (0.058)
Country of Birth (ref. Australia)
Oth English speaking 0.099 0.125 -0.097 0.188** 0.119
(0.160) (0.095) (0.094) (0.089) (0.088)
Asia 0.168 0.037 0.025 0.055 0.02
(0.105) (0.073) (0.065) (0.070) (0.066)
Other 0.399** 0.159 0.142 0.201 0.118
(0.179) (0.133) (0.121) (0.126) (0.123)
Marital status (ref. never married)
Married/de facto -0.335*** -0.165** -0.005 -0.063 0.008
(0.103) (0.074) (0.070) (0.074) (0.073)
Divorced/widowed -0.259** -0.123 0.066 -0.034 0.092
(0.123) (0.084) (0.079) (0.084) (0.081)
Employment status (ref. NILF)
Employed -0.009 -0.032 -0.074 -0.044 -0.087*
(0.084) (0.053) (0.048) (0.051) (0.048)
Unemployed -0.333 -0.127 0.018 -0.023 -0.269**
(0.265) (0.128) (0.102) (0.113) (0.120)
Resultsforthefirstthreshold–
betweenextremeandsevere
32. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
DIF adjusted indices
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
EQ-5DIndex
Index based on self-reports DIF-adjusted index
0.6
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1
EQ-5DIndex
Index based on self-reports DIF-adjusted index
Difference=0.049
Difference=0.095
33. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 2: Summary
• Vignettes can be used identify DIF in the EQ-5D-5L (at least in
certain age groups)
• Failure to adjust for DIF can lead to conclusions that are
misleading
• Further work is needed to achieve vignette equivalence
• Earlier work increased RC (rate vignettes as if it were
themselves, imagine person of similar age, avoided age
specific diseases) but did this come at the expense of VE?
• Further work required to understand what this means for
economic evaluations
• Knott et al (2016) Differential item functioning in the EQ-5D: an
exploratory analysis using anchoring vignettes. HEDG Working
paper
34. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 3: external application
• Funded by Monash Faculty of Business grant
• Often voiced concern is that the inclusion of vignettes in studies,
particularly clinical trials is not costless
• Application of vignettes has typically been limited to datasets
where they are collected
• Recent work (Harris et al, 2015) showed that it is possible to
correct for DIF using vignette responses collected externally to
the main dataset, using SRH and HILDA
• Research question
• Is it possible to adjust for DIF in the EQ-5D within a dataset
that did not include vignettes?
• If it’s possible, what effect does it have?
35. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Data sources
• Vignette data as before
• Multi Instrument Comparison (MIC) study recruited 8,000+
respondents in 6 countries to complete 6 of the most common
MAUIs, including the EQ-5D-5L (Richardson et al, 2012)
• Targeting of morbidity groups and the healthy public
• Wave 1 Australian sample N=1,341
• Given RC and VE only exist in 55+ age group, MIC external
sample N=656 and vignette sample N=914
• Key issue: how similar are the two groups, how applicable will the
vignette responses in the external data be to the MIC
respondents? Is the DIF problem in this sample the same as in
the other?
36. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Descriptive statistics
MIC sample (N = 656) Vignettes sample (N = 914)
Mean St. Dev. Mean St. Dev.
Female 0.447 0.498 0.497 0.500
Male 0.553 0.498 0.503 0.500
Aged 55-64 0.566 0.496 1 -
Aged 65+ 0.435 0.496 0 -
University degree (high) 0.349 0.477 0.309 0.462
Certificate/diploma (medium) 0.245 0.431 0.330 0.471
High school or less (low) 0.405 0.491 0.361 0.481
Born in Australia 0.686 0.465 0.756 0.430
Employed 0.244 0.430 0.528 0.500
Married 0.654 0.476 0.650 0.477
Asthma 0.061 0.240 0.166 0.373
Cancer 0.200 0.400 0.101 0.301
Respiratory 0.093 0.291 0.067 0.250
Depression 0.067 0.250 0.318 0.466
Diabetes 0.180 0.384 0.149 0.356
38. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
DIF adjustment – group differences
-0.004
0.054
0.038
0.093
0.065
0.08
-0.02
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Male - Female High educ - Low educ Migrant - Born Aus Employed - Not employed Married - Alone Aged 65 plus - Under 65
DifferenceinEQ-5D-5Lindices
Unadjusted scores DIF-adjusted scores
0.016
0.079
0.037
0.141
0.096 0.097
-0.02
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Male - Female High educ - Low educ Migrant - Born Aus Employed - Not employed Married - Alone Aged 65 plus - Under 65
DifferenceinEQ-5D-5Lindices
Unadjusted scores DIF-adjusted scores
MID=0.074
39. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Stage 3: summary
• It is possible to correct for DIF using responses to anchoring
vignettes that are collected externally to the main dataset of
interest
• Resulting QALY measures can be considered comparable across
different population groups
• Assuming reporting behaviour in each sample is the same
• Knott & Lorgelly (2016) Adjusting for differential item functioning
in the EQ-5D using externally-collected vignettes. HESG Paper
(Gran Canaria)
40. Application of anchoring vignettes to the EQ-5D-5L:
a possible solution to reporting heterogeneity in PROMs
Where to next?
• Better understanding of the vignette equivalence failure issue
• Will there always be a trade-off with response consistency?
• Is there value in exploring DIF cross-culturally?
• Multi-national clinical trials, often apply one country’s tariff as
if all respondents are within that country
• Is the external adjustment as good as (or a close substitute for)
collecting them within a study?
• What does this mean for economic evaluations and the decisions
they inform?
• Could response behaviour change over time?