Wounds and Injuries
Conditions
Keywords
Child Passenger Injury, Child Restraint Systems, Traffic Accidents
Brief summary
Seat belts protect people from injuries by diverting crash forces to stronger anatomical structures: the rib cage and the pelvis. Children between the ages of 4 and 8 years are typically not tall enough to wear the seat belt correctly across the chest and hips, and instead wear it on their abdomen and neck. When worn in this way, seat belts direct crash forces to these parts of the body, potentially causing serious damage to internal organs and the spine. For this reason, children of these ages need to use a booster seat; a safety device that prevents seat belt related injuries by raising the child and ensuring the straps are correctly worn across the thorax and hips. In Canada, half of the children who should be using booster seats are prematurely restrained using only the seat belt. The present research project seeks to develop and test a novel intervention to encourage booster seat use. Many Canadian provinces have enacted laws mandating use, and have developed and implemented evidence-based education programs. Despite these efforts, new approaches to encourage booster seat use are required. In 2010, more than 10 years after booster seats became mandatory, the rate of utilization in the Canadian provinces of Ontario and Quebec was still low (25%). Furthermore, recent research indicates that parents' perception of the safety benefit of booster seats is the strongest predictor of use, yet no study to date has tested an education intervention that increases perceived benefit; instead, these interventions focus on teaching guidelines (i.e., minimum and maximum age, height, and weight to determine when a child should use a booster seat, and when it is safe for a child to use only the seat belt). The present approach to encouraging booster seat use is novel, because it increases perceived benefit by teaching two principles: (1) seat belts prevent injuries by redirecting crash forces to stronger parts of the body (rib cage and pelvis); and (2), without booster seats, children would wear the seat belt on their abdomen and neck, which directs crash forces to more vulnerable anatomical structures (internal organs and spine). Once parents grasp these two principles, they are expected to better appreciate the safety benefit of booster seats and, thus, be more likely to use them.
Detailed description
The education material currently available in the Transport Canada website will be enhanced, by adding an introduction that describes how seat belts and booster seats work (i.e., these devices help redirect crash forces to stronger parts to the body: rib cage and pelvis). Objective of the trial: To determine if the enhanced material is better than the current Transport Canada information at increasing perceived safety benefit and intention to use booster seats. Design: Concurrent two-group parallel randomized controlled trial. Randomization: Block randomization will be used to assign participants to either intervention or control groups. Participants and researchers will be blinded to allocation. Participants. 303 mothers and 303 fathers of children 4 to 8 years old will be invited to participate, irrespective of whether they use booster seats always, occasionally, or never. A sample of 606 participants provides sufficient power to detect a mean difference in perceived benefit that separates those parents who consistently restrain their child in booster seats from those who do not. Sample size was estimated with the TwoSampleMean function for trials that test superiority of interventions (TrialSize package for R). Participants in the trial will receive $1/each for the completion of the survey. Based on information from studies with similar characteristics, the expected response rate is 40%. Setting and Procedures. The trial will be conducted entirely online. Participants will be recruited through an online market research firm, Maru/Matchbox, which maintains a nationwide panel of 130,000 individuals whose distribution represents the Canadian population. Maru/Matchbox will send an email invitation to participate along with a link to the online survey. The landing page of the survey will provide description of the study for parents to read. The online survey will be set up in such a way that participants won't be able to start answering questions, unless they consent by clicking the I agree button. Participants, will be advised to print and keep a copy of the consent form either as PDF or as hard copy. After consenting to participate, the online trial will proceed as follows: 1. Participants will complete a baseline questionnaire. 2. The system will randomly assign the participant to either the intervention or the control group. Randomization will be stratified by sex, child age, and jurisdiction to ensure both groups are equal. 3. Participants in the intervention group will be presented the enhanced booster seat material, while participants in the control group will be presented the current Transport Canada booster seat material. Material provided to both groups will be stripped of logos (Transport Canada logos and corporate identity), but will be properly cited. 4. Participants will complete post-intervention questionnaire. 5. Participants in the intervention group will be asked one or two questions to ensure they did not misunderstood the information in an unintended way. If a parent answers incorrectly, the system will clarify the information immediately after. 6. Participants in the control group will be given the option to view the enhanced booster seat material, in order to give them the opportunity to benefit from the intervention.
Interventions
BEHAVIORALTransport Canada material
The current Transport Canada booster seat education material focuses on imparting guidelines; that is, it describes, in plain language, the minimum and maximum ages, heights, and weights to determine when a child should use a booster seat, and when it is safe for a child to use only the seat belt. This material does not describe the principle of operation of seat belts (i.e., redirecting crash forces to the rib cage and pelvis), nor the principle of operation of booster seats (i.e., ensuring the seat belt is placed correctly across the chest and hips).
BEHAVIORALEnhanced material
Enhancements to the booster seat education material were developed based on the hypothesis that parents would better appreciate the additional injury risk reduction afforded by booster seats, if they understand that: (1) seat belts prevent injuries by redirecting crash forces to stronger parts of the body (i.e., rib cage and pelvis); and (2), without booster seats, children would wear the seat belt on their abdomen and neck, which directs crash forces to more vulnerable anatomical structures (i.e., internal organs and spine).
Sponsors
Child and Family Research Institute
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
PARTICIPANT MASKING: Participants will be told the purpose of the study is to evaluate parents' reactions to two different information materials about booster seats and seatbelts. INVESTIGATOR MASKING: The study will be conducted entirely online using a online research platform, so allocation will be masked to all investigators. OUTCOMES ASSESSOR MASKING: Outcome evaluation will be conducted online using an online survey tool, so allocation will be masked to outcome assessors. STATISTICAL ANALYSIS: Allocation in the online survey will be coded using random numbers unknown to the person conducting statistical analysis.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Parents of children 4 thorough 8 years old * Residing in any Canadian Province * Fluent in English * Drive with their child at least once a month
Exclusion criteria
\- Child has a physical condition that requires special transportation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Perceived Safety Benefit of Booster Seats | Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes) | Assessed with the Perceived Benefit sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). The Perceived Benefit subscale evaluates parents' perception of the general safety afforded by booster seats (e.g., prevents children from being injured during normal driving). The Perceived Benefit sub-scale of the BSASabb ranges from 1 to 5, and higher scores mean better outcome. |
| Change in Key Benefit of Booster Seats | Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes) | Change in key safety was measured as the difference between post- and pre-intervention scores assessed with the Key Benefit sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). The Key Benefit sub-scale evaluates parents' perception of the safety afforded by booster seats in relation to potentially fatal injuries to the spine and neck, a key feature of booster seats. The Key Benefit sub-scale of the BSASabb ranges from 1 to 5 and higher scores mean better outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Projected Intent to Use | Immediately after intervention (the mean duration of the intervention was 3 minutes) | Participants were asked to estimate how likely were their peers to use about booster seats, after reviewing the information they were assigned. The questionnaire was based on the Booster Seat Attitudes Scale (Cunningham et al., 2011). The idea behind this measure is that people judgments about what others would do reflect, in part, what they would do (Loewenstein, 2005). The scale ranges from 1 to 5 and higher scores mean better outcome. |
| Interest in the Communication Material | Immediately after intervention (the mean duration of the intervention was 3 minutes) | Number of seconds spent reviewing the material. |
| Change in Intention to Use Booster Seats | Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes) | Change in intention to use booster seats was measured as the difference between post- and pre-intervention scores in the Intent to Use sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). Intent to Use sub-scale evaluates parents' willingness to purchase and ensuring their child always rides on a booster seat. The Intention to Use of the BSASabb ranges from 1 to 5 and higher scores mean better outcome. |
| Applied Knowledge of Booster Seats | Immediately after intervention (the mean duration of the intervention was 3 minutes) | Participants were shown a picture of a child incorrectly restrained and were asked to identify the mistakes in the picture. Scores ranges from 0 to 3 and higher scores mean better outcome. |
| Projected Intent to Learn | Immediately after intervention (the mean duration of the intervention was 3 minutes) | Participants were asked to estimate how likely were their peers to learn about booster seats, after reviewing the information they were assigned. The questionnaire was based on the Booster Seat Attitudes Scale (Cunningham et al., 2011). The idea behind this measure is that people judgments about what others would do reflect, in part, what they would do (Loewenstein, 2005). The scale ranges from 1 to 5 and higher scores mean better outcome. |
| Interest in Additional Information | Immediately after intervention (the mean duration of the intervention was 3 minutes) | Whether parents review additional information offered as external links to legislation, car seat clinics, and list of product recalls. Measured as Yes or No. |
| General Knowledge of Booster Seats | immediately after intervention (the mean duration of the intervention was 3 minutes) | Participants were asked questions to assess how much general information about booster seats they retained: how booster seats prevent injuries as well as guidelines and recommendations. Scores ranges from 0 to 2 and higher scores mean better outcome. |
Countries
Canada
Participant flow
Recruitment details
Participants were recruited online, between the 10th and the 27th of December 2018, through a market research service, Maru Blue, which keeps a database of 130,000 individuals who have consented to receive invitations to online surveys. Individuals registered in the database were sent an email invitation, which included a link to our online survey.
Pre-assignment details
Our target sample size was 606, as stated in the protocol. However, we were able to enroll more than our target: 731
Participants by arm
| Arm | Count |
|---|---|
| Current Material Participants in this arm were shown the online Transport Canada Material that is was available at the time: https://tc.canada.ca/en/road-transportation/child-car-seat-safety/stage-3-booster-seats
Transport Canada material: The current Transport Canada booster seat education material focuses on imparting guidelines; that is, it describes, in plain language, the minimum and maximum ages, heights, and weights to determine when a child should use a booster seat, and when it is safe for a child to use only the seat belt. This material does not describe the principle of operation of seat belts (i.e., redirecting crash forces to the rib cage and pelvis), nor the principle of operation of booster seats (i.e., ensuring the seat belt is placed correctly across the chest and hips). | 364 |
| Enhanced Material Participants in this arm were shown an enhanced version of the online Transport Canada Material, which includes an introduction explaining how booster seats prevent injuries caused by seat belts.
Enhanced material: Enhancements to the booster seat education material were developed based on the hypothesis that parents would better appreciate the additional injury risk reduction afforded by booster seats, if they understand that: (1) seat belts prevent injuries by redirecting crash forces to stronger parts of the body (i.e., rib cage and pelvis); and (2), without booster seats, children would wear the seat belt on their abdomen and neck, which directs crash forces to more vulnerable anatomical structures (i.e., internal organs and spine). | 367 |
| Total | 731 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Dropped without completing treatment | 0 | 7 |
| Overall Study | Lost to Follow-up | 4 | 0 |
Baseline characteristics
| Characteristic | Enhanced Material | Total | Current Material |
|---|---|---|---|
| Age, Continuous | 39.16 Years STANDARD_DEVIATION 7.1 | 38.78 Years STANDARD_DEVIATION 7.04 | 38.40 Years STANDARD_DEVIATION 6.98 |
| Education Apprenticeship or trades | 52 Participants | 107 Participants | 55 Participants |
| Education Bachelor's degree | 89 Participants | 151 Participants | 62 Participants |
| Education College, CEGEP or equivalent | 68 Participants | 152 Participants | 84 Participants |
| Education High school certificate or equivalent | 36 Participants | 76 Participants | 40 Participants |
| Education Master's degree | 54 Participants | 113 Participants | 59 Participants |
| Education No certificate, diploma or degree | 18 Participants | 32 Participants | 14 Participants |
| Education PhD, MD, Dentist, or equivalent | 12 Participants | 24 Participants | 12 Participants |
| Education University certificate or diploma | 38 Participants | 76 Participants | 38 Participants |
| Intent to Learn about booster seats | 3.65 Scores on a scale from 1 to 5 STANDARD_DEVIATION 1.02 | 3.64 Scores on a scale from 1 to 5 STANDARD_DEVIATION 1.05 | 3.63 Scores on a scale from 1 to 5 STANDARD_DEVIATION 1.09 |
| Intent to use booster seats | 4.69 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.52 | 4.71 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.51 | 4.73 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.5 |
| Language spoken at home English | 339 Participants | 682 Participants | 343 Participants |
| Language spoken at home Other language | 28 Participants | 49 Participants | 21 Participants |
| Number of children Four or more | 37 Participants | 79 Participants | 42 Participants |
| Number of children One child | 81 Participants | 155 Participants | 74 Participants |
| Number of children Three children | 83 Participants | 145 Participants | 62 Participants |
| Number of children Two children | 166 Participants | 352 Participants | 186 Participants |
| Perceived Benefit of Booster Seats | 4.31 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.7 | 4.31 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.69 | 4.31 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.69 |
| Perceived key benefit of booster seats | 4.45 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.64 | 4.45 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.66 | 4.45 Scores on a scale from 1 to 5 STANDARD_DEVIATION 0.68 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Sex/Gender, Customized Fathers | 168 Participants | 341 Participants | 173 Participants |
| Sex/Gender, Customized Mothers | 199 Participants | 390 Participants | 191 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 0 |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Change in Key Benefit of Booster Seats
Change in key safety was measured as the difference between post- and pre-intervention scores assessed with the Key Benefit sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). The Key Benefit sub-scale evaluates parents' perception of the safety afforded by booster seats in relation to potentially fatal injuries to the spine and neck, a key feature of booster seats. The Key Benefit sub-scale of the BSASabb ranges from 1 to 5 and higher scores mean better outcome.
Time frame: Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data in Key Benefit sub-scale of the BSASabb were included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Change in Key Benefit of Booster Seats | 0.29 Scores on a scale from 1 to 5 | Standard Deviation 0.54 |
| Enhanced Material | Change in Key Benefit of Booster Seats | 0.15 Scores on a scale from 1 to 5 | Standard Deviation 0.5 |
p-value: 095% CI: [0.07, 0.22]t-test, 2 sided
Primary
Change in Perceived Safety Benefit of Booster Seats
Assessed with the Perceived Benefit sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). The Perceived Benefit subscale evaluates parents' perception of the general safety afforded by booster seats (e.g., prevents children from being injured during normal driving). The Perceived Benefit sub-scale of the BSASabb ranges from 1 to 5, and higher scores mean better outcome.
Time frame: Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data in the Perceived Benefit sub-scale of the BSASabb were included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Change in Perceived Safety Benefit of Booster Seats | 0.27 Scores on a scale from 1 to 5 | Standard Deviation 0.53 |
| Enhanced Material | Change in Perceived Safety Benefit of Booster Seats | 0.15 Scores on a scale from 1 to 5 | Standard Deviation 0.53 |
p-value: 0.00295% CI: [0.04, 0.2]t-test, 2 sided
Secondary
Applied Knowledge of Booster Seats
Participants were shown a picture of a child incorrectly restrained and were asked to identify the mistakes in the picture. Scores ranges from 0 to 3 and higher scores mean better outcome.
Time frame: Immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data on general knowledge of booster seats were included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Applied Knowledge of Booster Seats | 2.60 score on a scale from 0 to 3 | Standard Deviation 0.68 |
| Enhanced Material | Applied Knowledge of Booster Seats | 2.70 score on a scale from 0 to 3 | Standard Deviation 0.64 |
p-value: 0.06595% CI: [0, 0.19]t-test, 2 sided
Secondary
Change in Intention to Use Booster Seats
Change in intention to use booster seats was measured as the difference between post- and pre-intervention scores in the Intent to Use sub-scale of the BSASabb (an abridged version of the Booster Seat Attitudes Scale, Cunningham et al., 2011). Intent to Use sub-scale evaluates parents' willingness to purchase and ensuring their child always rides on a booster seat. The Intention to Use of the BSASabb ranges from 1 to 5 and higher scores mean better outcome.
Time frame: Immediately before intervention; immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data in the Intent to Use sub-scale of the BSASabb were included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Change in Intention to Use Booster Seats | 0.03 Scores on a scale from 1 to 5 | Standard Deviation 0.38 |
| Enhanced Material | Change in Intention to Use Booster Seats | 0.01 Scores on a scale from 1 to 5 | Standard Deviation 0.32 |
p-value: 0.35295% CI: [-0.03, 0.07]t-test, 2 sided
Secondary
General Knowledge of Booster Seats
Participants were asked questions to assess how much general information about booster seats they retained: how booster seats prevent injuries as well as guidelines and recommendations. Scores ranges from 0 to 2 and higher scores mean better outcome.
Time frame: immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data on general knowledge of booster seats were included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | General Knowledge of Booster Seats | 0.83 score on a scale from 0 to 2 | Standard Deviation 0.7 |
| Enhanced Material | General Knowledge of Booster Seats | 1.29 score on a scale from 0 to 2 | Standard Deviation 0.74 |
p-value: 095% CI: [0.34, 0.56]t-test, 2 sided
Secondary
Interest in Additional Information
Whether parents review additional information offered as external links to legislation, car seat clinics, and list of product recalls. Measured as Yes or No.
Time frame: Immediately after intervention (the mean duration of the intervention was 3 minutes)
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Current Material | Interest in Additional Information | Clicked links to additional information on booster seats | 17 Participants |
| Current Material | Interest in Additional Information | Did not clicked links to additional information on booster seats | 347 Participants |
| Enhanced Material | Interest in Additional Information | Clicked links to additional information on booster seats | 26 Participants |
| Enhanced Material | Interest in Additional Information | Did not clicked links to additional information on booster seats | 341 Participants |
Secondary
Interest in the Communication Material
Number of seconds spent reviewing the material.
Time frame: Immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants who completed their assigned material were included in this analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Interest in the Communication Material | 161 Seconds | Standard Deviation 190 |
| Enhanced Material | Interest in the Communication Material | 128 Seconds | Standard Deviation 218 |
p-value: 0.03395% CI: [2.65, 62.46]t-test, 2 sided
Secondary
Projected Intent to Learn
Participants were asked to estimate how likely were their peers to learn about booster seats, after reviewing the information they were assigned. The questionnaire was based on the Booster Seat Attitudes Scale (Cunningham et al., 2011). The idea behind this measure is that people judgments about what others would do reflect, in part, what they would do (Loewenstein, 2005). The scale ranges from 1 to 5 and higher scores mean better outcome.
Time frame: Immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data on the Projected Intent to Learn scale were included in this analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Projected Intent to Learn | 3.81 units on a scale from 1 to 5 | Standard Deviation 0.91 |
| Enhanced Material | Projected Intent to Learn | 3.95 units on a scale from 1 to 5 | Standard Deviation 0.89 |
p-value: 0.0395% CI: [0.01, 0.28]t-test, 2 sided
Secondary
Projected Intent to Use
Participants were asked to estimate how likely were their peers to use about booster seats, after reviewing the information they were assigned. The questionnaire was based on the Booster Seat Attitudes Scale (Cunningham et al., 2011). The idea behind this measure is that people judgments about what others would do reflect, in part, what they would do (Loewenstein, 2005). The scale ranges from 1 to 5 and higher scores mean better outcome.
Time frame: Immediately after intervention (the mean duration of the intervention was 3 minutes)
Population: Only participants with complete data on the Projected Intent to use scale were included in this analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Current Material | Projected Intent to Use | 4.46 Scores on a scale from 1 to 5 | Standard Deviation 0.62 |
| Enhanced Material | Projected Intent to Use | 4.62 Scores on a scale from 1 to 5 | Standard Deviation 0.53 |
p-value: 0.00295% CI: [0.05, 0.22]t-test, 2 sided