FALCon project: Measurment and modelling of [Function
Across the Life Course]
The MRC Unit for Lifelong health and Ageing (LHA) is leading a
cross-unit collaboration with the MRC Biostatistics Unit (Cambridge
University) and MRC CAiTE Centre (University of Bristol), MRC
Epidemiology Resource Centre (University of Southampton), MRC
Social and Public Health Sciences Unit (Glasgow University), on the
measurement and modelling of Function Across the Life Course.
Background
Many measures of physiological, cognitive and physical
function (e.g., blood pressure, IQ, grip strength) reach a peak (a
high functional level) early in life, remain relatively stable, and
then decline during older age. Repeated measures of function can
thus act as a dynamic tool to study the biological imprint of
physical and social exposures. Such measures of function are
important because they affect our immediate health and quality of
life; and also because they are predictors of future health,
likelihood of disease, and of mortality. As an example, research
has shown that acquiring a high peak bone mass (a marker of bone
health, fracture risk and osteoporosis) early in life reduces the
inevitable decline that occurs from our late 20’s. The level of
peak bone mass achieved thus serves as the “bone bank for the
remainder of life”. Signs of impaired function may act as
intermediate markers of underlying disease processes or accelerated
ageing, and importantly, indicate a need for early
intervention.
Epidemiological studies are increasingly including measures of
function as well as disease status, but there are no guiding
principles on which to base the choice and timing of measures. It
is also clear that in order to understand how measures of function
change with age and affect health over the entire life course we
need repeated measures from large numbers of individuals from birth
to death - to date, no single study has such information.
Currently, the best description of life course functional
trajectories will come from the pooling of data from cohorts
spanning the whole age range. Harmonisation of measures of function
across cohorts would facilitate this comparison, while development
of the statistical methods for combining trajectories is also
necessary. The FALCon project seeks to address these issues.
Objectives:
(1) Provide recommendations
for cohort studies on the measurement of physical, cognitive and
cardiovascular function:
- We are surveying MRC funded cohorts to identify if there are
ages where there is an absence of longitudinal data on measures of
function.
- Where there are gaps in knowledge, we are also carrying out
systematic reviews to synthesise the evidence on the relationship
between measures of cardiovascular, physical and cognitive function
and mortality and morbidity.
(2) Develop statistical models for the synthesis of function
across cohorts in order to model the whole life course
trajectory.
- We currently have data on repeated measures of function from
several cohorts covering different ages. We are investigating
methods of combining this information in a way that will enable us
to understand more about trajectories of function over the life
course.
- We are also investigating the utility of existing statistical
approaches such as growth mixture models for dealing with
longitudinal trajectories both as an exposure and an
outcome.
Investigators:
LHA:
Dr Rebecca Hardy (PI),
Professor Diana Kuh
Dr Andrew Wills
(Investigator Scientist),
External collaborators:
Dr Eleni Bakra (MRC Biostatistics Unit, Cambridge)
Dr Fiona Matthews, MRC Biostatistics Unit, Cambridge;
Professor Debbie Lawlor, MRC CAiTE Centre, University of
Bristol;
Professor Avan Aihie Sayer, MRC Epidemiology Resource Centre;
Ms Michaela Benzeval, MRC Social and Public Health Sciences
Unit
Other contributors:
Dr Rachel Cooper (LHA),
Dr Graciela Muniz-Terrera (MRC Biostatistics Unit, Cambridge).