A number of school‐based policies or practices have been found to be effective in
improving child diet and physical activity, and preventing excessive weight gain,
tobacco or harmful alcohol use. Schools, however, frequently fail to implement such
evidence‐based interventions. The primary aims of the review are to examine the effectiveness
of strategies aiming to improve the implementation of school‐based policies, programs
or practices to address child diet, physical activity, obesity, tobacco or alcohol
use. Secondary objectives of the review are to: Examine the effectiveness of implementation
strategies on health behaviour (e.g. fruit and vegetable consumption) and anthropometric
outcomes (e.g. BMI, weight); describe the impact of such strategies on the knowledge,
skills or attitudes of school staff involved in implementing health‐promoting policies,
programs or practices; describe the cost or cost‐effectiveness of such strategies;
and describe any unintended adverse effects of strategies on schools, school staff
or children. All electronic databases were searched on 16 July 2017 for studies published
up to 31 August 2016. We searched the following electronic databases: Cochrane Library
including the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; MEDLINE
In‐Process & Other Non‐Indexed Citations; Embase Classic and Embase; PsycINFO; Education
Resource Information Center (ERIC); Cumulative Index to Nursing and Allied Health
Literature (CINAHL); Dissertations and Theses; and SCOPUS. We screened reference lists
of all included trials for citations of other potentially relevant trials. We handsearched
all publications between 2011 and 2016 in two specialty journals ( Implementation
Science and Journal of Translational Behavioral Medicine ) and conducted searches
of the WHO International Clinical Trials Registry Platform (ICTRP) ( http://apps.who.int/trialsearch/
) as well as the US National Institutes of Health registry ( https://clinicaltrials.gov
). We consulted with experts in the field to identify other relevant research. 'Implementation'
was defined as the use of strategies to adopt and integrate evidence‐based health
interventions and to change practice patterns within specific settings. We included
any trial (randomised or non‐randomised) conducted at any scale, with a parallel control
group that compared a strategy to implement policies or practices to address diet,
physical activity, overweight or obesity, tobacco or alcohol use by school staff to
'no intervention', 'usual' practice or a different implementation strategy. Citation
screening, data extraction and assessment of risk of bias was performed by review
authors in pairs. Disagreements between review authors were resolved via consensus,
or if required, by a third author. Considerable trial heterogeneity precluded meta‐analysis.
We narratively synthesised trial findings by describing the effect size of the primary
outcome measure for policy or practice implementation (or the median of such measures
where a single primary outcome was not stated). We included 27 trials, 18 of which
were conducted in the USA. Nineteen studies employed randomised controlled trial (RCT)
designs. Fifteen trials tested strategies to implement healthy eating policies, practice
or programs; six trials tested strategies targeting physical activity policies or
practices; and three trials targeted tobacco policies or practices. Three trials targeted
a combination of risk factors. None of the included trials sought to increase the
implementation of interventions to delay initiation or reduce the consumption of alcohol.
All trials examined multi‐strategic implementation strategies and no two trials examined
the same combinations of implementation strategies. The most common implementation
strategies included educational materials, educational outreach and educational meetings.
For all outcomes, the overall quality of evidence was very low and the risk of bias
was high for the majority of trials for detection and performance bias. Among 13 trials
reporting dichotomous implementation outcomes—the proportion of schools or school
staff (e.g. classes) implementing a targeted policy or practice—the median unadjusted
(improvement) effect sizes ranged from 8.5% to 66.6%. Of seven trials reporting the
percentage of a practice, program or policy that had been implemented, the median
unadjusted effect (improvement), relative to the control ranged from ‐8% to 43%. The
effect, relative to control, reported in two trials assessing the impact of implementation
strategies on the time per week teachers spent delivering targeted policies or practices
ranged from 26.6 to 54.9 minutes per week. Among trials reporting other continuous
implementation outcomes, findings were mixed. Four trials were conducted of strategies
that sought to achieve implementation 'at scale', that is, across samples of at least
50 schools, of which improvements in implementation were reported in three trials.
The impact of interventions on student health behaviour or weight status were mixed.
Three of the eight trials with physical activity outcomes reported no significant
improvements. Two trials reported reductions in tobacco use among intervention relative
to control. Seven of nine trials reported no between‐group differences on student
overweight, obesity or adiposity. Positive improvements in child dietary intake were
generally reported among trials reporting these outcomes. Three trials assessed the
impact of implementation strategies on the attitudes of school staff and found mixed
effects. Two trials specified in the study methods an assessment of potential unintended
adverse effects, of which, they reported none. One trial reported implementation support
did not significantly increase school revenue or expenses and another, conducted a
formal economic evaluation, reporting the intervention to be cost‐effective. Trial
heterogeneity, and the lack of consistent terminology describing implementation strategies,
were important limitations of the review. Given the very low quality of the available
evidence, it is uncertain whether the strategies tested improve implementation of
the targeted school‐based policies or practices, student health behaviours, or the
knowledge or attitudes of school staff. It is also uncertain if strategies to improve
implementation are cost‐effective or if they result in unintended adverse consequences.
Further research is required to guide efforts to facilitate the translation of evidence
into practice in this setting. Improving the implementation of school‐based policies
and practices to improve student health The review question: The review sought to
assess how effective strategies were in supporting the implementation of school‐based
policies and practices to address student diet, physical activity, excessive weight
gain, tobacco or alcohol use. We also assessed if these strategies led to improvements
in these student health behaviours or weight status, enhanced school staff attitudes
or knowledge regarding implementation, had any adverse effects, and were cost‐effective.
Background: Research has identified a range of school‐based policies and practices
that may be potentially effective in improving student health behaviours. Despite
this, such policies and practices are often not implemented in schools, even in circumstances
where it is mandatory to do so. Unless evidence‐based policies and practices are implemented,
they can not benefit public health. Study characteristics: We included 27 trials,
18 of which were conducted in the USA. Fifeteen trials tested strategies to implement
healthy eating policies, practice or programs; six trials tested strategies targeting
physical activity policies or practices; and three trials targeted tobacco policies
or practices. Three trials targeted a combination of health behaviours. None of the
included trials sought to increase the implementation of interventions to delay initiation
or reduce the consumption of alcohol. The trials tested a range of implementation
support strategies, including educational materials, educational meetings, the use
of opinion leaders, external funding, local consensus processes, and tailored interventions.
Search date: The evidence is current to 31 August 2016. Key results: It is uncertain
whether the strategies tested improve implementation of the targeted school‐based
policies or practices, student health behaviours, or the knowledge or attitudes of
school staff. It is also uncertain whether the strategies tested result in unintended
adverse effects or whether they are cost‐effective. Limitations: Trial heterogeneity,
and the lack of consistent terminology describing implementation strategies were important
limitations of the review. Quality of evidence: We rated the overall quality of evidence
as very low for all outcomes that included trial‐reported effects.