Preventing Childhood Obesity - Evidence Policy and Practice.pdf

Monitoring of childhood obesity
Table 21.1 Continued
x
x
x
x
x
Adequate staffing and facilities for testing, diagnosis, treatment and program management should be available
prior to the commencement of the screening program.
All other options for managing the condition should have been considered (for example, improving treatment and
providing other services), to ensure that no more cost - effective intervention could be introduced or current
interventions increased within the resources available.
Evidence - based information, explaining the consequences of testing, investigation and treatment, should be
made available to potential participants to assist them in making an informed choice.
Public pressure for widening the eligibility criteria for reducing the screening interval, and for increasing the
sensitivity of the testing process, should be anticipated. Decisions about these parameters should be scientifically
justifiable to the public.
If screening is for a mutation, the program should be acceptable to people identified as carriers and to other
family members.
( NCMP ) parents of all participants in the NCMP will
receive their child ’ s results, regardless of their weight,
unless they request otherwise. 11 Parents still have the
opportunity to withdraw their child from the program,
and children can also decide not to participate on the
day. Changes were made in 2007, making it possible
to access individual data, link them to names and
addresses and contact the parents by mail to give them
the results of the measurement. It is unclear how
much of this feedback will be effective as an intervention
and how parents will react to this information.
Monitoring of e ffects of i nterventions
When the effectiveness of interventions is assessed
through a monitoring system, this usually means that
there is no randomized controlled trial design. Usually
this means that the serial assessment of outcomes
(such as mean body weight, BMI or body fatness or
the percentage of people with overweight or obesity)
are related to the received dose of an intervention used
before or during the observation period. Sometimes
these can be compared to the intensity of the exposure
to the intervention (intervention dose) and changes in
outcome measures, such as health - related variables.
For example, if one or a number of regions or states
within a country implement a comprehensive obesity
prevention plan including school food policies, social
marketing, bans on advertising on unhealthy foods
and promotion of physical activity, changes in trends
of children ’ s BMI could be compared to trends in
those regions or states with no obesity prevention
strategies.
Where there are no populations who can serve as
controls there are limitations to such evaluations,
although in many instances there are no alternatives.
Randomized controlled designs may not always be a
better alternative. This is partly because complex community
interventions do not always lend themselves
to randomization and because intense monitoring of
behaviour, anthropometric measurements and health
outcomes may actually serve as an effective intervention
itself in the control groups. This is sometimes
referred to as the Hawthorne effect. 28 It also possible
that control areas or communities are contaminated
though the media and adopt at least parts of the intervention.
This has been documented, for instance in
the Heartbeat Wales project. 29
The evaluation of complex community interventions
depends on the degree of exposure to the intervention
that can be identified, and to which degree the
effects of general secular trends can excluded. In the
1970s and 1980s, a series of population - based community
intervention studies were carried out in high -
income countries to reduce risk factors for chronic
disease. These studies focused on either change in
health behaviors or on risk factors such as tobacco use,
bodyweight, cholesterol and blood pressure, as well as
a reduction in morbidity and mortality due to cardiovascular
disease. In general, they included a combination
of community - wide actions as well as those
focused on individuals identified as being at high
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risk.
Gaziano et al 30 have reviewed the evidence of
community interventions aimed at the prevention
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