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Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
https://doi.org/10.1186/s12889-019-7469-7
S T U D Y P R O T O C O L
Open Access
Increasing awareness of food-choking and
nutrition in children through education of
caregivers: the CHOP community
intervention trial study protocol
Giulia Lorenzoni1, Danila Azzolina1,2, Solidea Baldas3, Gianni Messi4, Corrado Lanera1, Megan A. French3,
1982
Liviana Da Dalt5 and Dario Gregori1*
Act
Abstract
Background: Choking is one of the leading causes of death among unintentional injuries in young children. Food
choking represents a considerable public health burden, which might be reduced through increased effective
preventative education programs. We present a protocol for a community intervention trial termed CHOP (CHOking
Prevention project) that aimed to teach Italian families how to prevent food choking injuries and increase knowledge
relating to nutrition.
Information
Methods: Italian educational facilities were enrolled. Stratified randomization blocked by geographical area was performed.
Each stratum was randomized to one of three different intervention strategies or to a control group. Educational
intervention was delivered in the schools by experts and certified trainers as per the following three intervention
strategies: directly to families (Strategy A); to teaching staff only, who subsequently delivered the same educational
intervention to families (Strategy B); to health service staff only, who then delivered the educational intervention to
Official
teaching staff, who subsequently delivered the intervention to families (Strategy C).
Participants completed a questionnaire about their knowledge on the topics presented during the educational
the
interventions (pre-, post-, and follow-up of intervention). Information from the questionnaires was synthetized into 6
indicators in order to measure how effective each intervention strategy was.
Discussion: The issue of food choking injuries in children is relevant to public health. The protocol we present provides
an opportunity to progress towards overcoming such challenges through a working model that can be implemented
under
also in other countries.
Trial registration:
ClinicalTrials.gov NCT03218618. The study was registered on 14 July 2017.
Keywords: Choking prevention, Foreign body, Public health, CHOP community intervention trial
Background
referred to as “injuries” as oppose to “accidents”
[1,
2].
Released
Historically, injuries were considered “accidents” occur-
This also applies to choking injuries. In recent years, the
ring by chance. However, increased knowledge about
development of prevention strategies for non-food chok-
factors that affect the occurrence of such events has
ing injuries has resulted in a reduction of the occurrence
raised awareness about the fact that they may be predict-
of this type of injury. For example, injuries due to toys
able and preventable, and that they can therefore be
(and toy parts) decreased after the development and im-
plementation of an ad-hoc regulation on toy safety and
associated public health campaigns
[3], which informed
* Correspondence:
[email address]
1
adult supervisors on the importance of choosing certi-
Unit of Biostatistics, Epidemiology and Public Health, Department of Cardiac,
Thoracic, Vascular Sciences and Public Health, University of Padova, Via
fied toys and nursery products.
Loredan, 18, 35131 Padova, Italy
Full list of author information is available at the end of the article
© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License
(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
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Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
Page 2 of 7
Insufficient attention has, however, been given to food
three different school-based intervention strategies. The
related choking injuries even though some studies have
CHOP project aimed to: (i) teach families how to pre-
shown that caregivers often lack knowledge about this
vent food choking injuries in children; (ii) inform pol-
issue. For example, Nichols et al.
[4] conducted a survey
icy-makers on the effectiveness of community-based
among parents of infants and toddlers relating to food
intervention schemes as oppose to intervention on an
and non-food hazardous items, and about the actions
individual basis; (iii) determine the intervention strategy
considered necessary to prevent choking injuries. Inter-
that offers the best compromise between educational
estingly, knowledge about hazardous non-food items
effectiveness and cost effectiveness. The expectation is
was found to be higher than knowledge of food items,
that the optimal strategy will be introduced into schools
and parents who were unaware of food related choking
across Italy as the first Italian public health intervention
hazards were more likely to give their children foods
program to combat the issue of food choking.
that pose a high risk of choking. Consistent with these
findings are those of a survey conducted on Japanese
Methods/design
mothers with children under the age of two [
5], which
Trial design
1982
showed that the mothers did not consider nuts and
The CHOP project was designed as a community inter-
seeds (which are the food items most frequently involved
vention trial to compare three different school-based
Act
in choking episodes [
6]) as hazardous food items to be
intervention strategies. The project delivered education
avoided by infants and toddlers. Additionally, Susy Safe
on primary and secondary food choking prevention and
data, perhaps one of the world’s largest registries collect-
nutrition under the umbrella topic of nutrition educa-
ing data on foreign body (FB) injuries in children aged
tion, and was designed with the intension of reaching as
0–14 years old [
7], shows that about 40% of recorded
many people as possible through the participation of
food injuries occurred while children were eating with-
families in schools. The study protocol followed the
out adult supervision. The remaining 60% occurred
SPIRIT statement [
16].
when children were eating improper food (or food pre-
Information
pared improperly) despite adult supervision [
8]. These
Study setting
findings denote a concerning lack of knowledge about
Italian educational facilities (nurseries, kindergartens,
choking hazard among caregivers.
and primary schools) were included in the trial. Educa-
The need for choking prevention strategies is evidenced
tional facilities were stratified such that each stratum in-
Official
by epidemiological data [
9]. Choking is one of the leading
cluded an educational facility from each educational
causes of death among unintentional injuries in young
stage (i.e., each stratum includes one nursery, one kin-
children, and remains relevant until the age of 14 [
10].
dergarten, and one primary school). Healthcare staff,
the
Additionally, food-related choking injuries account for up
teachers, and families (parents or guardians) of children
to 60–80% of all choking injuries in some studies [
11].
attending the schools participated in the project. The
This is due in part to physiological characteristics of chil-
project did not involve children (under 16 years of age)
dren that make them more prone to choking while eating
but only families (parents or guardians).
under
[
12]. Food items most frequently involved in FB injuries
Study particpants (healthcare staff, teachers, and fam-
share specific characteristics of size, consistency/texture,
ilies -parents or guardians-) were informed about the na-
and shape, which make them difficult to chew for young
ture and the scope of the study by study coordinators. If
children
[13]. Consequently, food items may be swallowed
they agree to participate, they must provide written in-
before the child has chewed them sufficiently. Depending
formed consent in accordance with Ethical Committee
on the size and texture of the item involved, once in the
(EC), using an EC approved informed consent form, in-
Released
airways they can conform to the pharynx and cause a
cluding the consent for the use and processing of their
blockage or reach the lower respiratory tract.
personal details.
Despite the huge burden on public health services that
is consequence of food choking injuries, public health
Eligibility criteria
programs in this field are sparse, and only a few studies
Eligibility criteria for school participation was as follows:
have evaluated the effectiveness of such strategies. How-
ever, two studies that were conducted in Israel [
14] and
availability of at least one subject from the school’s
in Crete
[15] showed that a reduction of choking cases
health service;
in children occurred after the implementation of educa-
availability of a room with suitable technology
tional programs on choking prevention.
(monitor, sound system) for educational
Here we report on the CHOP (CHOking Prevention)
intervention;
study protocol, which evaluated the effectiveness of pub-
approval of the school’s inclusion by the competent
lic health intervention on food choking by comparing
authority.
link to page 3
Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
Page 3 of 7
Also, parents or guardians, school health service
A lecture on primary prevention of food choking
personnel, and teaching staff had to be:
and on nutrition (see below) given by experienced
trainers.
aged between 18 and 60 years old;
Training on maneuvers to dislodge FBs (secondary
without hearing or eyesight impairments;
prevention) demonstrated by trainers certified by
consenting to the project participation.
the Italian Society of Pediatric Emergency Medicine
(SIMEUP).
Interventions
Distance education via a Massive Open Online
Educational intervention was delivered in the schools by
Course (MOOC) to reinforce the lecture content
experts and certified trainers as per the following three
(see below).
intervention strategies (Fig.
1).
Lecture content included:
Strategy A: directly to families.
Strategy B: to teaching staff only, who subsequently
Primary prevention of food choking injuries
1982
delivered the same educational intervention to
(epidemiology of the phenomenon; characteristics
families.
that make children more prone to choke than
Act
Strategy C: to health service staff only, who then
adults; obstruction mechanisms; detailed description
delivered the educational intervention to teaching
of hazardous food products; information on the
staff, who subsequently delivered the intervention to
characteristics of FBs (shape, texture, and size) that
families.
are associated with a high risk of aspiration;
Control group: no educational intervention.
recommendations for food preparation).
Basic information regarding food labels, including an
The same educational intervention was delivered in all
explanation of the types of information reported on
strategies and consisted of the following:
labels and their meaning).
Information
Official
the
under
Released
Fig. 1 Flow-chart of the CHOP study
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Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
Page 4 of 7
Tips for food waste prevention.
consisted of a checklist to evaluate their ability to perform
maneuvers to dislodge FBs and thus assess the effectiveness
The lecture and the training were carried out on the
of the secondary prevention training.
same day. At the end of the session, participants were
Participants involved in the control group completed
asked to subscribe and join the MOOC to reinforce their
only once a telephone-administered socio-demographic
learning. The MOOC is an innovative learning modality
questionnaire and a questionnaire to assess their know-
and consists of a series of free and brief videos that are
ledge on food choking prevention, food labeling, and
available on a dedicated website (
www.safefood4chil-
food waste prevention (the same questionnaire was ad-
dren.org). The online course is available in English,
ministered to participants involved in each intervention
Italian, and Italian sign language, and will eventually be
strategy immediately after and 1-month after the educa-
available in French, Arabic, Chinese, Japanese, Malay,
tional intervention).
and Portuguese. In each MOOC video, a field expert (a
professor of biostatistics and epidemiology, an ENT doc-
tor, a pediatrician, a researcher, and a professional chef
Outcomes
1982
de cuisine) presents on the following topics:
Participants were assessed as having either passed or
failed the skills test. The responses from the question-
Act
epidemiology of choking injuries;
naire (completed at post-, and follow-up stages) were
psycho-physiological characteristics that make
synthesized into indicators in order to measure how
children more prone to choke;
effective each intervention strategy (A, B and C) was in
FB obstruction mechanisms;
improving knowledge about primary prevention of food
hazardous food items;
choking. Four indicators (1–4, Table
1) based on differ-
food preparation;
ent topics relating to choking, and two indicators
hazardous non-food items;
(Table
2) for nutrition topics, were calculated for each
first aid and maneuvers for pediatric unblocking;
stage of each strategy. Weighting of the answers within
Information
food labeling;
each indicator is shown in Table
1 for choking education
food waste prevention.
and Table
2 for the nutrition education.
Assignment of interventions
Official
Stratified randomization blocked by geographical area
Sample size
was performed. Each stratum was randomized to one of
Sample size estimation was performed, as recommended
three different intervention strategies or to the control
for such types of studies
[17], by taking into account the
the
group (Fig.
1). The randomization was blocked by geo-
intra-cluster correlation coefficient (ICC), ρ, and the
graphical area (Northern, Central, Southern, and major
intra-stratum correlation coefficient, ρm (where m is the
Islands). Participants and trainers were not blinded to
number of strata). Equation
1 shows the recommended
strata allocation, but those in charge of data analyses
approach for calculating the difference in mean outcome
under
and interpretation of results were blinded.
considering multiple comparisons for continuous out-
comes [
18].
Data collection methods
Data collection differed for participants involved in the
2
intervention strategies (A, B, C) and in the control group
2 z α þ zβ σ2
2nc
-since they did not undergo the educational interven-
ni ¼
ð1Þ
μ
ð −μ Þ2
Released
tion-, even though the instruments employed were the
1
2
same.
Before the educational intervention, participants in each
Where ni is the estimated sample size for i = 1, 2
intervention strategy (A, B, C) completed a socio-demo-
groups, nc is the number of pairwise comparisons, and
graphic questionnaire and a questionnaire about their
μ1 − μ2 is the expected difference in proportions among
baseline knowledge on food choking prevention, food
groups, α is the significance level and β is the probability
labeling, and food waste prevention. A questionnaire was
of Type II error in any hypothesis test.
then completed by participants involved in each interven-
In this research framework, it is important to consider
tion strategy (A, B, C) to obtain data relating to taught ma-
a sample size estimation procedure that takes the ICC,
terial, with questionnaire being completed, i) immediately
ρ, and intra-stratum, ρm, into account. An approach that
after (post), and ii) 1 month after (telephone follow-up)
does this is provided by Crespi
[17] and is represented
educational interventions. A skills test was also given to
by Eq.
2. Following this approach, the overall sample size
them immediately after the educational intervention and
is:
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Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
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Table 1 Indicator topics, questions, and weighted scores used to assess CHOP choking educational intervention strategies
Indicator
Topic
Question
Weight of question
1
Epidemiological knowledge
Do you know why children are at risk of choking?
0.33
At what age are children at highest risk of choking?
0.33
How many deaths per year are estimated to result from foreign body
0.33
injuries in EU countries in children between 0 and 14 years of age?
2
Risk Perception
Are magnets, if swallowed in numbers greater than one, dangerous?
0.15
What objects are most frequently involved in foreign body injuries?
0.35
What objects cause the most serious and fatal injuries?
0.35
Why are button batteries dangerous if ingested?
0.15
3
Rules for food preparation
When should it be assumed that a child has inhaled a foreign body,
0.1
and what should be done?
What size should food be prepared to?
0.1
1982
How should we prepare and cook meat and fish to reduce the risk of
0.3
choking and injury?
Act
How should you cut wurstel and hot dogs?
0.3
What should children do during meals and when eating?
0.1
Do particular food preparation techniques help to reduce the risk of
0.1
choking?
4
Ability to recognize hazardous foods
Which food represents a high risk of choking to children?
0.4
Why is food of a round shape hazardous?
0.4
Why do we have to give babies nuts in a ground form incorporated to
0.1
Information
other foods with a soft consistency (e.g., yogurt)?
At what age can children be given candies and sweets?
0.1
2
undertaking a Cluster Randomized Controlled trial
4 z α þ zβ σ2 1 þ m
ð −1Þρ−mρ ρ
Official
2nc
m
ð
for evaluating an injury prevention education
2Þ
ðμ −μ Þ2
program in 20 primary schools [
20].
1
2
Intra stratum correlation, ρm = 0.05 (as assumed for ρ)
the
The sample size was calculated for three pairwise com-
A difference in mean of the correct answer
parisons between the intervention and control groups [
19]
corresponding to an effect of 0.183.
for the difference in mean outcome, and with consider-
A pooled variance σ2 for the difference in means
ation of a Bonferroni correction on the α significance
outcomes equal to 1
under
value [
18]. The sample size was calculated according to
A baseline mean μ1 of the correct answer as 0.7.
the following assumptions:
The resultant sample size that we determined in the
α = 0.05 (adjusted for three pairwise comparisons).
trial was 1426.
Power = 0.8
The study size was adjusted taking into account a 15%
m = 4 (minimum number of families in schools).
drop out rate; for this reason 1670 participants in 48
Released
nc=3 pairwise comparisons
schools (35 per-school) were enrolled.
We assume ρ = 0.05. This is based on a study that
Computations were performed using the ‘R’ System
reported the same expected value though
(Version 3.3.2) [
21].
Table 2 Indicator topics, questions, and weighted scores used to assess CHOP nutrition educational intervention strategies
Indicator
Topic
Question
Weighted score
1
Knowledge about nutritional
Identification of the obligations for producers with regard
0.5
indications and food labeling.
to food labeling introduced by regulation n. 1169/2011.
Definition of nutritional indication reported by regulation n.
0.5
1924/2006.
2
Knowledge about the prevention
Identification of the precautions to reduce food waste at home.
0.5
of food waste.
Definition of the minimum terms of conserving food.
0.5
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Appendix 5
Lorenzoni et al. BMC Public Health (2019) 19:1156
Page 6 of 7
Statistical methods.
inequalities in the ability to access food choking prevention
Indicators were reported as mean (± standard devi-
training.
ation). Wilcoxon-Kruskal-Wallis tests were computed in
The protocol we present, based on the CHOP commu-
order to compare each intervention strategy with the
nity intervention trial, provides an opportunity to overcome
control group at each study stage (post and follow-up):
such challenges through a working model that can be
i) Strategy A vs. Control Group ii) Startegy B vs. Control
implemented in other countries in order to reduce the pub-
Group iii) Strategy C vs. Control Group. The term of
lic health burden of food choking injuries in children and
comparison (Control Group) was the same at both study
increase nutritional education to caregivers.
stages (post and follow-up) since participants involved in
the control group underwent questionannire administra-
Abbreviations
CHOP: CHOking Prevention project; FB: Foreign Body; MOOC: Massive Open
tion only once. To account for multiplicity of testing,
Online Course; SES: Socio-Economic Status
p-values were adjusted according to the Benjamini-
Hochberg procedure at each study stage (post and follow-
Acknowledgements
Not applicable
up). In addition to that, to account for potential con-
1982
founders (socio-demographic characteristics and baseline
Authors’ contributions
knowledge on choking prevention, food labeling, and food
DG study conception; DA study design; GL study design and draft of the
Act
waste prevention), regression models were estimated, one
work; CL data analysis; GM, MF, and LDD substantial revision of the work; SB
data acquisition. All authors have approved the submitted version (and any
for each indicator, at both study stages (post and follow-
substantially modified version that involves the author’s contribution to the
up).
study) and have agreed both to be personally accountable for the author’s
own contributions and to ensure that questions related to the accuracy or
integrity of any part of the work, even ones in which the author was not
personally involved, are appropriately investigated, resolved, and the
Discussion
resolution documented in the literature.
The issue of food choking injuries in children is relevant
Funding
from a public health perspective, but it is often neglected
Information
This work is supported by an unrestricted grant from the Italian Ministry of
[
22]. Italian public health interventions are scant, and
Health, Directorate General for Food Hygiene and Safety and Nutrition. The
only a few initiatives have been made globally to reduce
funding body was not involved in the design of the study and collection,
analysis, and interpretation of data and in writing the manuscript.
the public health burden of food choking injuries. The
United States and Sweden are the only countries to have
Availability of data and materials
Official
developed specific regulations aimed at choking preven-
The datasets used and/or analysed during the current study are available
from the corresponding author on reasonable request.
tion [
23–25]. In Italy, there are no other known initiatives
to address and combat this concerning public health issue.
the Ethicsapprovalandconsenttoparticipate
Training on food choking prevention is currently done on
The CHOP project was approved by the “Comitato etico per la
a voluntary basis with families incurring costs themselves.
Sperimentazione clinica della Provincia di Padova” (4277/U6/17). Study
particpants (healthcare staff, teachers, and families -parents or guardians-)
The cost of training can represent a considerable eco-
were informed about the nature and the scope of the study by study
nomic burden for low-income Italian families, and this
coordinators. If they agree to participate, they must provide written informed
under
creates inequality in the ability to access to choking
consent in accordance with Ethical Committee (EC), using an EC approved
informed consent form, including the consent for the use and processing of
prevention training. This is especially concerning given
their personal details. The study did not involve children.
that children from families with a low socio-economic sta-
tus (SES) are more prone to choking, and more likely to
Consent for publication
Not applicable
experience injuries in general, in comparison to families
with a medium-high SES [
26].
Competing interests
Released
The timing of the delivery of educational intervention
The authors declare that they have no competing interests.
on food choking is critical if families are to be trained
Author details
before solid foods are introduced into their children’s
1Unit of Biostatistics, Epidemiology and Public Health, Department of Cardiac,
diets (usually at around 6 months of age). Ideally, some
Thoracic, Vascular Sciences and Public Health, University of Padova, Via
training should be provided before children are born (e.g.,
Loredan, 18, 35131 Padova, Italy. 2Department of Translational Medicine,
University of Piemonte Orientale, Novara, Italy. 3Prochild Onlus, Trieste, Italy.
during prenatal classes). However, in Italy, a school-based
4Department of Pediatrics, Burlo Garofolo Hospital, Trieste, Italy. 5Division of
intervention currently represents the most feasible and
Pediatric Emergency Medicine, Department of Women’s and Children’s
realistic way to reach as many families as possible because
Health, University of Padova, Padova, Italy.
school attendance is compulsory, whereas other occasions
Received: 2 August 2019 Accepted: 11 August 2019
for parents-to-be and existing parents to meet are not
compulsory (e.g., prenatal class). It has also been demon-
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