forbidding options or significantly changing economic incentives’. They say that
NUDGEs are ‘easy and cheap to avoid’ and note that, ‘putting fruit at eye level counts
as a nudge... banning junk food does not’. It is possible to design interventions that
use low value financial incentives but will they be effective? It is also possible to design
easy default opt-in systems but, as with organ donation, some of these systems would
require regulatory and legislative change (Marteau et al., 2011). Given the diverse range
of interventions that could be characterized as NUDGEs, it does not make sense to
ask whether NUDGEs per se work but, instead, to evaluate each of these interventions.
Some may work well in particular contexts, while others do not.
In this section we have seen how identification of regulatory processes can facilitate
specification of a range of change techniques that may operate on aspects of the
reflective or impulsive system or both. We have also seen how these techniques can
be embedded in a range of delivery methods and delivered by a variety of sources
and/or facilitators with particular competencies and relationships to recipients. Each
of these separate intervention characteristics (see Table 9.1) needs to be carefully
considered during the intervention mapping process so that relevant change techniques
can be tailored to particular behaviour change problems within particular target
groups.
EVALUATION OF BEHAVIOUR CHANGE INTERVENTIONS
The final stage of the intervention mapping process is evaluation. We can distinguish
between three broad types: (1) outcome evaluations (that answer the question, did
the intervention change the behaviour it targeted?); (2) process evaluations (that answer
the question, how did the intervention work and did it change the regulatory mech -
anisms targeted?); and (3) economic evaluations (that answer the question, how much
does the intervention cost for a given degree of effectiveness). We have noted that
once the intervention objectives are defined in stage 2 of intervention mapping, it is
important to identify measures to be used in the evaluation. Outcome measures
may assess health or behaviour patterns or both, depending on the intervention
objectives. Assessing health outcomes (such as weight loss or STI rates) allows tests
of hypothesized links between behaviour change and health enhancement or disease
incidence. For example, does increasing self-reported condom use among a target
group decrease STI incidence?
When an intervention is found to be effective an economic evaluation can clarify
how much it will cost to implement the intervention. This is important because health
care funds are limited and implementing expensive interventions may require cuts
in other services. It is worth noting, however, that when preventive health behaviour
interventions are effective they are likely to be cost-effective because of high treatment
costs. For example, the lifetime cost of treating a HIV positive person in the UK
has been estimated at more than £240,000, so even expensive HIV-preventive inter -
ventions are likely to be cost-saving if they are effective in reducing HIV incidence.
Similarly, an intervention that prevents obesity, heart attacks or falls among the elderly
is very likely to be cost-saving and, therefore, cost-effective.
In this section we will not provide guidance on how to undertake evaluations. This
is readily available elsewhere. A project funded by the UK School for Public Health
CHANGING BEHAVIOUR 215