TABLE 4
Strategies to Ameliorate Injuries
Drawing on the same social-ecologic principles
that help describe the factors affecting the occurrence
of injuries, William Haddon developed two frame-
works for conceptualizing injury interventions. The
first outlined injury interventions aimed at different
phases in the energy transfer process. The ten coun-
termeasures were directed at reducing the potential
for damage to the body from an energy source. Table
5 shows examples pertaining to reducing childhood
bicycle crash injuries.
Later, Haddon proposed a different, but similar,
model to help stimulate intervention development:
the Haddon Matrix. This model is widely used to
identify potential interventions, and has two dimen-
sions. The first depicts the target of change, including
the person at risk (or the person’s caretaker); the
source of energy (e.g., products to which children are
exposed—toys, motor vehicles, household poisons);
the physical environment (e.g., playgrounds, road-
ways, homes, schools, day-care facilities); or the social
environment (e.g., norms about behaviors such as
drinking or child discipline; regulatory policies gov-
erning drinking ages, playground safety, or use of bi-
cycle helmets). The second dimension depicts the
phase at which the intervention has its effect—
whether at the time of the injury event (e.g., a seat belt
that deploys during a crash); at a time prior to the
event, helping to prevent the event (e.g., antilock
brakes); or after the event to reduce the effects of the
event (e.g., gas tanks engineered to prevent explo-
sions). Putting these two dimensions together creates
a four by three matrix. Using the matrix as a brain-
storming tool, one can fill in the twelve cells with ideas
of potential interventions (see example in Table 5
pertaining to bicycle safety).
Choosing among the multiple alternative inter-
vention ideas can be complex but several principles
can help sort out the types of intervention ideas. In-
terventions may be voluntary or mandatory. And they
might be active or passive. Active interventions re-
quire that the person to be protected takes protective
action (e.g., putting on a bike helmet, testing water
temperature in the baby’s bathtub). In contrast, pas-
sive interventions are those that do not require action
on the part of the individual being protected or delib-
erate action by a caretaker. Rather, they are engi-
neered or set up such that protection is automatic
(e.g., installation of airbags in cars, setting the tem-
perature for hot water heaters at a safe level; automat-
ic shutoffs on appliances). In general, interventions
that require less individual effort result in more suc-
cess. That is, passive interventions tend to be more
successful than ones that require individual action.
There are significant trade-offs, however, in making
choices among the different options.
A third dimension added to the Haddon Matrix
by Carol Runyan addresses the kinds of trade-offs
that frequently occur in public health decision mak-
ing. By considering alternative interventions derived
from the two-dimensional matrix, a planner can ex-
amine the value issues involved in each choice and
compare various options. As a result, decisions can be
made more logically and the rationale for a given de-
cision can be explained to others. For example, an in-
tervention requiring restrictions on the purchase of
firearms limits the freedom of gun enthusiasts, while
at the same time affording greater freedom for chil-
dren to live in environments with fewer guns and thus
increasing child safety. Likewise, some interventions
are more costly than others, requiring design changes
in products (e.g., improvements in car design to re-
duce rollovers in crashes) or in the design of physicalINJURIES 215