Age-related diseases and functional decline put health care systems at a challenge.
It is still unclear, whether a compression or extension of morbidity or some sort
of balance is likely to be expected. Probably, different scenarios may either coexist
or change depending upon both the type of health outcome (particular diseases, multi-morbidity
and disability) and contextual factors (socioeconomic, cultural and political). Population-based
studies at the national or regional level will provide valid and comprehensive information
on age-related changes in population health, as continuous health monitoring will
permit analyses of time trends. Prospective studies on lifetime health trajectories
are necessary to identify determinants of healthy ageing and critical phases of decline.
A premise to achieve all this including cross-national comparability is to establish
a consensus platform for harmonising methods, key concepts and indicators.
Against this background, the 2nd European Workshop on Health and Disability Surveillance
in Ageing Populations (EUWAP) held at the Robert Koch Institute (RKI) in Berlin, Germany
on November 22-23, 2012, pursued two goals, (1) to take stock of existing European
and global approaches for surveying ageing populations, and (2) to identify perspectives
for joint future collaborations related to cross-national comparisons and the harmonisation
of methods and indicators. The presentations and plenary discussions unfolded the
large differences which currently still exist regarding concepts, indicators and instruments
to assess healthy ageing as well as age-specific aspects of health, e.g. multi-morbidity,
frailty, and disability to perform activities of daily living.
In her keynote lecture, Dorly Deeg highlighted the need for a priori harmonising concepts
and instruments by illustrating difficulties arising from early post-harmonisation
approaches in two European projects, the EU-funded Comparison of Longitudinal European
Studies on Ageing (CLESA, 2001-2004)) and more recently, the European Project on Osteoarthritis
(EPOSA, 2009-2013). Large EU-funded research consortia such as the Survey of Health,
Ageing and Retirement in Europe (SHARE) and the Consortium on Health and Ageing: Networks
of Cohorts in Europe and the United States (CHANCES) have taken efforts to harmonise
data collection. As reviewed by Simone Croezen and co-authors, SHARE results have
been compared with aggregate results from large national or cross-national health
surveys, such as nationwide Health Interview Surveys (HIS), the European Health Interview
Survey (EHIS), the European Social Survey (ESS), the European Union Labour Force Survey
(EU-LFS) and the European Union Statistics on Income and Living Conditions (EU-SILC).
Comparisons of SHARE results will be extended to both, aggregate and individual-level
data from other national health surveys. CHANCES has implemented a specific work package
(CHANCES Health Module), in order to establish a core set of health indicators that
provide comparable data between all participating cohort studies. In their presentation,
Simone Croezen and Martin Bobak outlined the main concepts and methods applied. The
EU-funded research consortium of Collaborative Research on Ageing in Europe (COURAGE)
implemented the WHO standard to assess disability and health (ICF; International Classification
of Functioning, Disability, and Health). Matilde Leonardi summarised the COURAGE protocol
which addresses research, policy and civil society for defining future directions
in view of an ageing Europe. A global perspective was provided by Somnath Chatterji
who in his presentation illustrated the WHO Study on global Ageing and Adult Health
(SAGE). This study has been ongoing for more than a decade using instruments adapted
from those of the World Health Survey (WHS) and sixteen other surveys on ageing. SAGE
covers multiple domains of health and populations aged 50+ years in six middle and
low income countries (China, Ghana, India, Mexico, Russian Federation, and South Africa).
Cross-study comparisons with other large studies like SHARE are part of the SAGE concept.
Apart from differences between countries and cohorts, comparisons of results between
different studies are hampered by the complexity of health concepts (e.g. multi-morbidity,
functional capacity, and disability) and health determinants (e.g. health-related
behaviour, quality of healthcare, and socioeconomic context conditions). More importantly,
specific components of these concepts are changing over time requiring adaption of
indicators and instruments, as Marti Parker emphasised.
Which social, psychological and biological factors are setting the course for healthy
ageing already in young age and across the life-time are major questions focused by
an inter-disciplinary project on Healthy Ageing across the Life Course (HALCyon) led
by Diana Kuh. HALCyon encompasses data from nine birth cohorts in Great Britain. In
the context of a life course perspective, health inequalities are one out of seven
main priorities worked by Carol Jagger within FUTURAGE, an EU-funded project of 12
EU-countries and Israel which developed a road map for the next decade of ageing research
in Europe.
Frailty and disability are important dimensions of health in older people, but are
unevenly defined and measured. The above mentioned WHO classification of disabilities
(ICF) is mainly focusing on physical functioning. KORA-Age, a longitudinal multi-disciplinary
cohort study (region Augsburg, Germany) integrates functioning based on ICF into a
comprehensive view on prevalence and determinants of multi-morbidity, disability and
successful ageing, as Eva Grill explained. According to the widely used Fried frailty
index, three out of five characteristics (weakness, slowness, exhaustion, weight loss,
physical inactivity) characterise a person as frail. However, a generally accepted
definition is still pending. A modification of the Fried Frailty Criteria introduced
by Hermann Brenner initiated a lively discussion. His modified index predicted a higher
mortality even among 50-64 year olds based on ESTHER, a cohort study of older adults
in Saarland, Germany.
An important indicator of both disability and frailty is slower gait speed. New data
from the English Longitudinal Study on Ageing (ELSA), presented by Panayotes Demakakos
revealed a bidirectional association between gait speed and depressive symptoms. How
changes in self-rated health, health behaviour, social participation and related socioeconomic
conditions are interacting, has been investigated in the German Ageing Survey (DEAS).
As pointed out by Susanne Wurm, DEAS as an interview-based survey system including
repeated nationally representative surveys of persons aged 40+ years, permits comparisons
between different birth cohorts at the same age and provides the option to adapt to
new indicators every six years. The continuous national health monitoring system at
the RKI also permits time trend analyses, although comparisons are still limited to
only a few points in time. As exemplified by Christa Scheidt-Nave in her presentation,
several health indicators relevant to the population 65-79 years can be compared between
the first wave of the German Health Interview and Examination Survey for Adults (DEGS1)
conducted in 2008-2011 and the German National Health Interview and Examination Survey
conducted more than a decade earlier in 1998.
EUWAP came at the right point in time and with the clear message to strengthen harmonisation
efforts. For the future, even closer collaboration and net-working between the different
research consortia are intended, in order to facilitate pooled analyses, cross-country
comparisons, and validation studies.
Please see Additional file 1 for the programme of the EUWAP workshop.
Supplementary Material
Additional file 1
EUWAP workshop programme
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