Strengths and limitations
This review was conducted by a task force of diverse clinicians, allied
health professionals, public representatives, teachers and researchers.
This was a strength because it meant that interventions and outcomes
were considered on clinical and methodological grounds, with robust
checks by multiple experts.
The review provides an up-to-date summary of research, with two thirds
of the included studies being published in the past decade. However, it
has several limitations. The available evidence is heterogeneous and
mostly at moderate or high risk of bias. Meta-analysis was not
appropriate because the interventions and outcomes varied greatly and
there were too few studies with similar outcomes. A number of studies
examined outcomes that may not be the most helpful when seeking to
assess effectiveness, such as whether people carry autoinjectors or
short-term changes in quality of life. Very few studies reported in
detail on mortality, admissions, preferences or resource use. There was
also a lack of evidence about emergency management outside hospital.
Not all available interventions are included in the review because data
from registry studies, cohort studies and similar were not included.
These designs have often been used to explore educational interventions
or to track the value of preventive approaches.