Transcript Working Paper No.1 22 November 2005 STATISTICAL COMMISSION and UN ECONOMIC COMMISSION FOR EUROPE STATISTICAL OFFICE OF THE EUROPEAN COMMUNITIES (EUROSTAT) CONFERENCE OF EUROPEAN STATISTICIANS WORLD HEALTH ORGANIZATION (WHO) Joint UNECE/WHO/Eurostat Meeting on.

Working Paper No.1
22 November 2005
STATISTICAL COMMISSION and
UN ECONOMIC COMMISSION FOR
EUROPE
STATISTICAL OFFICE OF THE
EUROPEAN COMMUNITIES
(EUROSTAT)
CONFERENCE OF EUROPEAN
STATISTICIANS
WORLD HEALTH
ORGANIZATION (WHO)
Joint UNECE/WHO/Eurostat Meeting
on the Measurement of Health Status
(Budapest, Hungary, 14-16 November 2005)
Session 1-Invited paper
Health as a multi-dimensional
construct and
cross-population comparability
Colin Mathers (WHO)
on behalf of
Taskforce on Health Status
Evidence and Information for Policy
Background
• Previous meeting (Geneva May 2004)
– Broad agreement on approach
– Taskforce set up to develop proposals for instrument
– Also to further articulate the arguments supporting the
conceptual approach
• Taskforce has prepared three papers
– on conceptual approach
– criteria for choice of domains, and
– proposals for items
• This talk will give overview of paper 1
Evidence and Information for Policy
Outcome of Geneva 2004 meeting
• Focus is on measurement of health
states of individuals in surveys
• This requires a multi-dimensional
approach: a focus on a core set of
domains of functioning rather than on a
single global question
• Measurement focus is on an individual's
capacity to function in each domain.
Evidence and Information for Policy
Rationale for further articulation
To support the instrument development
process, it is important to have:
– a clear conceptual framework for defining
and choosing health domains
– clear and unambiguous definitions of what it
is intended to measure in health domains
Evidence and Information for Policy
Overview of issues addressed
•
•
•
•
•
Health status and health states
Multi-dimensional approach
ICF as the framework
What should be measured in domains
Distinguishing health states from
determinants and consequences
• Health states as attributes of individuals
• Cross-population comparability
Evidence and Information for Policy
Health status and health states
HEALTH STATUS
Health states
(capacities)
Determinants
of health
Genetic contribution
Lifestyle/behaviour
Domain 1
Physiological
Physiological
risk
factors
risk factors and
and risk
risk markers
markers
Diseases,
symptoms
and injuries
Domain 2
Death
.
.
Domain N1
Physical environment
.
.
Economic environment
Domain N2
Quality of life
Wellbeing
Social environment
Evidence and Information for Policy
Health status and health states
• Health states: functioning in a set of
domains "right now"
• Health states may potentially include some
or all ICF categories, not just the
parsimonious set chosen for measurement
• Health status: includes health states,
diseases and injuries, mortality risks,
physiological risk markers and POSSIBLY
health prognosis, resilience, risk factors.
Evidence and Information for Policy
Health trajectories and health states
100
90
B
Physically fit,
unipolar depression
during younger
adult ages
% full health
80
70
60
50
C
HIV
positive
40
30
A
smoker,
atherosclerosis
from age 45, later
heart disease
20
10
0
0
20
40
60
80
100
Age (years)
Evidence and Information for Policy
Domains of health
Mobility
Affect
Pain
Cognition
Self-Care
Usual
Activities
Overall level
of health
Health state valuations
Evidence and Information for Policy
Summarizing the measurements
Domains of health
Mobility
Affect
Pain
(c1, c2, c3, ……., cn)
v = f (c1, c2, c3, ……., cn)
Cognition
Self-Care
Usual
Activities
Health state profile
summary index of health state
+ indicators for mortality risks by cause, age, sex etc
+ indicators for disease and injury causes
+ indicators for risk factors and determinants
+ indicators for health interventions
+ indicators for other aspects of well-being/quality of life
+ …..
Evidence and Information for Policy
Health
status
Multi-dimensional approach
During the last three decades, there has
been general acceptance of an approach
to describing health states and disability of
individuals in terms of multiple domains of
health, and in developing self-report
instruments that seek information on each
of these domains
Evidence and Information for Policy
Examples of health domains
WHO World
EUROQOL
Health Survey
HUI-3
SF-36
Mobility
Mobility
Ambulation
Physical functioning
Self-care
Self-care
Dexterity
Physical role
Interpersonal
activities
Usual activities
Speech
Social functioning
Affect
Affect
Emotion
Mental/emotional
functioning
Pain
Pain
Pain
Pain and discomfort
Cognition
Cognition
Cognition
Emotional role
Sleep/Energy
hearing
Vitality
Vision
Vision
Overall health
Evidence and Information for Policy
Health State Descriptions
Core health domains – common to most instruments
Mobility
Affect
Pain
Cognition
Other potential health domains
Vision
Hearing
Vitaity
Digestion
Interpersonal
Skiing
Evidence and Information for Policy
Challenge for the development of
a health state interview instrument
Skiing?
Vision
Mobility
Cognition
Communi
cating
Hearing
Interpersonal
relationships
????
Universe of health
domains
Identify the
most
parsimonious
set of health
domains with
the highest
explanatory
value.
Evidence and Information for Policy
International Classification of
Functioning and Health
ICF
Body structures
and functions
Domains of
activities and
participation
Function relative
to biological
norms
Functioning
in standard
environment
Functioning
in current
environment
Impairments
Capacity
Performance
Evidence and Information for Policy
ICF as the framework
• Provides conceptual underpinning
(universe of domains, plus impairment,
capacity and performance)
• Provides a starting point for identifying a
parsimonious set of domains
• These may be domains, subdomains or
items in the ICF classificatory framework
• Does not provide guidance on which
domains are core 'health' or parsimonious
Evidence and Information for Policy
What should be measured in
domains
• Body functions and structures impairment
• Activity/participation domains 
Capacity OR Performance
• Measurements of these quantities must at
minimum be for ordered categorical values
• Quantity should map to a unidimensional
scale (observed or latent, ordinal or
cardinal) not mix two or more dimensions
Evidence and Information for Policy
Capacity versus performance
• Performance measures difficulty in doing domain
tasks in the current environment
• Capacity measures difficulty in doing domain
tasks in a standardized environment
• eg. for seeing a standard environment might
involve clear air and normal levels of good lighting
• Performance changes with changes in the
environment, whereas capacity does not
• How far does a questionnaire need to go in
defining normative environment?
Evidence and Information for Policy
Determinants and consequences
• Important to distinguish health states from
determinants and consequences
• The same determinant may be associated
with different health states in different
individuals
• The same health states may be
associated with different levels of well
being and quality of life in different
individuals
Evidence and Information for Policy
Causes of health states
Environmental factors
Underlying disease and injury
causes according to ICD rules
HIV/AIDS
Diabetes
Panic
disorder
Road traffic
accident
Health state
Mobility
Affect
Pain
Cognition
Self-Care
Usual
Activities
Evidence and Information for Policy
Causes of health states
Environmental factors
Risk factors
Physical
inactivity
Smoking
Unsafe sex
Overweight
Disease and injury causes
HIV/AIDS
Diabetes
Panic
disorder
Coronary heart
disease
Road traffic
accident
Health state
Mobility
Affect
Pain
Cognition
Self-Care
Usual
Activities
Evidence and Information for Policy
Attributes of individuals
• Health states are individual attributes
• Measured at individual level (not at level
of body parts, or of groups such as
families, households, cities etc)
• Aggregated across individuals to produce
summary information for population
groups (eg. prevalence rates for difficulties
in domains, average levels of domain
capacities etc)
Evidence and Information for Policy
Cross-population comparability
• Same measurement set (domains,
capacities, scales etc)
• Same questions and instruments
- cultural and translation issues
• Addressing the fundamental problem of
comparability of use of response categories
eg. does 'moderate difficulty' in mobility
mean the same thing to a 80 year old and a
20 year old, to an American and a Chinese?
• Addressed in more detail in later session
Evidence and Information for Policy
Operational issues
• Time frame for questions on current
health state
• How explicit do we need to be in
survey questions on distinction
between capacity and performance?
• What about aids and appliances, eg.
hearing aids, glasses, contact lens
Evidence and Information for Policy
Terminology
Health status --
used generally to refer to all measures
related to health (diseases, health states, mortality risks,
risk factors?, prognosis? )
Health state –
capacities of an individual in all important
domains of health
Health profile -- a vector of capacity scores for important
domains of health
Health state valuation -- a preference based single
cardinal number summarizing the health profile
Quality of life measure
-- refers to a broader class of
appraisal measures that may relate to health status,
wellbeing, satisfaction or utility
Evidence and Information for Policy
Agreement on a common framework
for measuring health status
• Health states are an multi-dimensional attributes
of individuals
• Measurement of health states  determining
capacities of individuals on multiple domains of
health
• Functioning within health domains is
conceptually distinct from overall well-being or
quality of life
• Health states must be kept distinct from
determinants and interventions
Evidence and Information for Policy