Preventing Childhood Obesity - Evidence Policy and Practice.pdf

Chapter 20
forecasts about the growth in the obesity problem.
Whilst several writers in the 1990s 2,3 noted that such
“ cost of illness ” ( COI ) studies were not particularly
common in the area of obesity, more recently,
authors 1,4 have referred to the growing literature documenting
the economic costs of obesity. Since our
earlier documentation of such COI studies of obesity, 1
there have been more studies, including for non -
Western jurisdictions.
5,6
Whilst such COI studies vary in their methodology,
they generally measure costs within a prevalence -
based framework. 3 The annual cost burden stemming
from all cases of obesity - related disease (new or pre -
existing) is measured, as the study purpose is generally
to inform cost control or financial planning. This contrasts
with incidence - based studies, 7 which measure
the lifetime costs associated with new cases only, as a
baseline against which new measures can be assessed.
Most studies confine the cost burden to direct health
sector costs arising from the current prevalence and
treatment of obesity, 8 with few taking into consideration
indirect costs arising from lost productivity 9 or
diminished social functioning and quality of life. 10 The
lack of consensus about obesity - related illnesses is evidenced
by differences between studies in terms of the
range of co - morbidities included. Studies vary in
terms of the BMI cut - off points used to define obesity,
as well as the perspective employed from which to
measure costs. Most studies assume a national health
system perspective, while some assume a narrower
reference frame in terms of geographical jurisdiction 11
or target group. 12
However, regardless of their choice of methods,
these COI studies comprise essentially “ descriptive ”
research focusing on the size of the obesity problem.
They quantify the magnitude of the issue and estimate
the associated disease burden in monetary terms. Such
studies are premised on the basis that knowledge of
the costs stemming from an illness will be important
in informing decision making around resource allocation.
They are considered a valuable tool when advocating
for the deployment of additional resources
towards obesity prevention, and have been employed
by agencies such as the World Bank and the World
Health Organization.
However, COI studies have also been the centre of
active debate among economists. 13 – 15 While acknowledging
that they may serve three purposes (to justify
budgets, to help set funding priorities and to develop
intervention programs), Rice 13 argues that the methods
need to be sufficiently detailed to permit transparency
and to enable the reader to assess whether the results
are “ fact or fiction ”. Byford et al 14 pose three key arguments
against the conduct and use of COI studies:
first, high costs do not necessarily indicate inefficiency
and waste; second, the supposed “ cost savings ” of
either fully or partially preventing a disease are likely
to be overstated and partly illusory; and third, the condition
may not necessarily be amenable to treatment.
More recently, there has been similar questioning
about the value of such studies among economists
working in the obesity field. 4,16 Roux and Donaldson 4
are highly critical of the economic credentials of such
studies and conclude that they add little to the obesity
debate, apart from confirming that obesity is a serious
societal issue. In an earlier publication, 1 we took a
more positive yet cautious approach to COI studies.
While acknowledging that descriptive cost estimates
can be of value to planners, we also stressed that COI
estimates should not be overinterpreted. More importantly,
used sensibly and carefully, COI estimates
could also have a role beyond simple description and
monitoring, as an input into evaluation studies and
broad - based priority setting exercises.
The third task of health economics, explanation
of obesity, is a relatively new and underdeveloped
field. Rosin 17 recently surveyed the growing economic
literature on the causes of obesity epidemic, and
concluded that the key economic influences on obesity
prevalence are food prices, working mothers, urbanization
and technological change.
Box 20.1 Glossary of e conomic
t erms
Cost – benefit analysis: An analytical tool for estimating
the net social benefit of an intervention as the incremental
benefit less the incremental costs, with all
benefits and costs measured in monetary terms.
Cost –effectiveness analysis: An analytic tool in which
costs and benefits of a program and at least one
alternative (usually current practice) are calculated
and presented in a ratio of incremental cost to incremental
benefit. Effects are measured as physical
health outcomes (such as weight lost, BMI units
saved or life years saved).
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