Effectiveness of the head CT choice decision aid in parents of children with minor head trauma: study protocol for a multicenter randomized trial
Effectiveness of the head CT choice decision aid in parents of children with minor head trauma: study protocol for a multicenter randomized trial
Erik P Hess 0 1 8 13
Kirk D Wyatt 12
Anupam B Kharbanda 11
Jeffrey P Louie 10
Peter S Dayan 15
Leah Tzimenatos 14
Sandra L Wootton-Gorges 9
James L Homme 6
Laurie Pencille RN 1
Annie LeBlanc 1 8 13
Jessica J Westphal 7
Kathy Shepel 4
Nilay D Shah 1 8 13
Megan Branda 1 8 13
Jeph Herrin 2 5
Victor M Montori 1 3
Nathan Kuppermann 14
0 Department of Emergency Medicine, Division of Emergency Medicine Research, Mayo Clinic , 200 First Street SW, 55905 Rochester, MN , USA
1 Knowledge and Evaluation Research Unit, Mayo Clinic , 200 First Street SW, 55905 Rochester, MN , USA
2 Health Research and Educational Trust , 1 N Franklin St, 60606 Chicago, IL , USA
3 Division of Endocrinology and Metabolism, Department of Internal Medicine, Mayo Clinic , 200 First Street SW, 55902 Rochester, MN , USA
4 Section of Creative Media, Mayo Clinic , 200 First Street SW, 55902 Rochester, MN , USA
5 Department of Cardiology, Yale University School of Medicine , 330 Cedar St, Boardman 110, P.O. Box 208056, 06520-8056 New Haven, CT , USA
6 Division of Pediatric Emergency Medicine, Departments of Emergency Medicine and Pediatrics, Mayo Clinic , 200 First Street SW, 55902 Rochester, MN , USA
7 Parent Representative , Rochester, MN , USA
8 Division of Health Care Policy and Research, Department of Health Sciences Research, Mayo Clinic , 200 First Street SW, 55905 Rochester, MN , USA
9 Department of Radiology, University of California Davis School of Medicine , 4860 Y Street, Suite 3100, 95817 Davis, CA , USA
10 University of Minnesota Amplatz Children's Hospital , 2450 Riverside Ave, 55455 Minneapolis, MN , USA
11 Children's Hospitals and Clinics of Minnesota , 345 North Smith Avenue, 55102 St. Paul, MN , USA
12 Mayo Medical School, Mayo Clinic College of Medicine , 200 First Street SW, 55902 Rochester, MN , USA
13 Robert D and Patricia E Kern Center for the Science of Healthcare Delivery, Mayo Clinic , 200 First Street SW, 55902 Rochester, MN , USA
14 Departments of Emergency Medicine and Pediatrics, University of California Davis School of Medicine , 2315 Stockton Boulevard, 95817 Davis, CA , USA
15 Departments of Emergency Medicine and Pediatrics, Columbia University College of Physicians and Surgeons , 3959 Broadway CHN, 1-116 10032 New York, NY , USA
Background: Blunt head trauma is a common cause of death and disability in children worldwide. Cranial computed tomography (CT), the reference standard for the diagnosis of traumatic brain injury (TBI), exposes children to ionizing radiation which has been linked to the development of brain tumors, leukemia, and other cancers. We describe the methods used to develop and test the effectiveness of a decision aid to facilitate shared decision-making with parents regarding whether to obtain a head CT scan or to further observe their child at home. Methods/Design: This is a protocol for a multicenter clinician-level parallel randomized trial to compare an intervention group receiving a decision aid, 'Head CT Choice', to a control group receiving usual care. The trial will be conducted at five diverse emergency departments (EDs) in Minnesota and California. Clinicians will be randomized to decision aid or usual care. Parents visiting the ED with children who are less than 18-years-old, have experienced blunt head trauma within 24 hours, and have one or two risk factors for clinically-important TBI (ciTBI) from the Pediatric Emergency Care Applied Research Network head injury clinical prediction rules will be eligible for enrollment. We will measure the effect of Head CT Choice on: (1) parent knowledge regarding their child's risk of ciTBI, the available diagnostic options, and the risks of radiation exposure associated with a cranial CT scan (primary outcome); (2) parent engagement in the decision-making process; (3) the degree of conflict parents experience related to feeling uninformed; (4) patient and clinician satisfaction with the decision made; (5) the rate of ciTBI at seven days; (6) the proportion of patients in whom a cranial CT scan is obtained; and (7) seven-day healthcare utilization. To capture these outcomes, we will administer parent and clinician surveys immediately after each clinical encounter, obtain video recordings of parent-clinician discussions, administer parent healthcare utilization diaries, analyze hospital billing records, review the electronic medical record, and conduct telephone follow-up. Discussion: This multicenter trial will robustly assess the effectiveness of a decision aid on patient-centered outcomes, safety, and healthcare utilization in parents of children with minor head trauma in five diverse EDs. Trial registration: ClinicalTrials.gov registration number: NCT02063087. Registration date February 13, 2014.
Blunt head trauma is a common cause of death and
disability in children worldwide and accounts for
approximately 52,000 deaths and 275,000 hospital
admissions in the United States annually . Each year more
than 650,000 children visit emergency departments
(EDs) in the United States with apparently minor blunt
head trauma (Glasgow Coma Scale (GCS) scores of 14
to 15) .
A cranial computed tomography (CT) scan, the
reference standard test for the emergent diagnosis of traumatic
brain injury (TBI) in children with blunt head trauma,
exposes children to ionizing radiation which has been linked
to the development of brain tumors, leukemia, and other
cancers [3,4]. Furthermore, although radiation exposure
from a single head CT scan may not significantly increase
an individual’s risk of cancer, patients often undergo
multiple CT examinations over their lifetime and the
cumulative radiation dose may exceed the 50 mSv  threshold
that has been linked to the development of cancer among
atomic bomb survivors .
One method to reduce CT use in patients with blunt
head trauma is through evidence-based clinical
prediction rules . In 2009, Kuppermann et al. derived and
validated two clinical prediction rules to accurately
identify children at very low risk for clinically-important
TBIs (ciTBIs) . The rules were developed from a
cohort of more than 42,000 children with minor blunt
head trauma among 25 EDs in the United States. They
have been externally validated  and are accurate for
use in clinical practice . Two rules were created, one
for children younger than 2 years and a second for
children between 2 and 18-years-old. The rules and study
data allow for the classification of children into three
risk groups: high risk, for whom a CT scan is
recommended (risk of ciTBI for the younger than 2 and 2 to
18-years-old age groups is 4.4% and 4.3%, respectively);
moderate risk, for whom observation or a CT scan are
reasonable options depending on parental preference,
clinician experience, and other factors (risk of ciTBI for
the younger than 2 and 2 to 18-years-old age groups is
0.9% and 0.8%, respectively); and low risk, for whom a
CT scan is typically not recommended (risk of ciTBI
for the younger than 2 and 2 to 18-years-old age groups
is <0.02% and <0.05%, respectively) . Although the
prediction rules recommend observation or a CT scan
as reasonable options for children in the moderate risk
group, the rules provide little guidance for clinicians
regarding how to weigh each of these factors and engage
parents in the decision-making process.
Shared decision-making (SDM) is a process of
decisionmaking in medicine that has several key features: the
involvement of the patient (or parent, in a child’s case) and
the clinician, a sharing of information by both parties, and
both parties taking steps to reach an agreement about
which management option to implement . While SDM
may occur in a routine discussion during a clinical
encounter, clinical decision-support tools may be
necessary to effectively present comparative effectiveness
research findings in a way that facilitates SDM. Decision
aids provide the best scientific evidence available to
support decision-making, prompt clarification of
patient values and preferences, and have become
increasingly used to provide the necessary decision support for
To facilitate SDM between clinicians and parents of
children with minor head trauma at low-moderate risk
for ciTBI, we sought to develop and test a decision aid,
‘Head CT Choice’. Specifically, we aimed to incorporate
risk estimates for ciTBI from the Pediatric Emergency
Care Applied Research Network (PECARN) prediction
rules, along with the perspectives of parents and other
stakeholders, in an iterative development process to
produce a decision aid that is ready for testing. We
hypothesized that use of the decision aid will significantly
increase parents’ knowledge and satisfaction and safely
tailor the rate of cranial CT scan and seven-day
healthcare utilization to risk-informed parent preferences. In
this manuscript, we describe the methods and protocol
used to develop and refine the Head CT Choice decision
aid and how we will test its effectiveness in a multicenter
This practical  multicenter clinician-level parallel
randomized trial compares an intervention group
receiving a structured risk assessment and corresponding
decision aid (Head CT Choice) to a control group receiving
usual care. Institutional Review Board (IRB) approval
has been obtained from the Mayo Clinic IRB (approval
number: 13–004659), the University of Minnesota IRB
(approval number: 1401 M46802), the Children’s Hospitals
and Clinics of Minnesota IRB (approval number: 1312–
117) and the University of California Davis IRB (approval
number: 587396). The trial is registered at clinicaltrials.
gov (registration number: NCT02063087).
The decision aid was developed and refined at the Mayo
Clinic in Rochester, Minnesota (United States). The
clinical trial will take place in five EDs in the United States:
four in Minnesota and one in California: Mayo Clinic
(an academic ED serving a largely rural population),
University of Minnesota Amplatz Children’s Hospital (a
university-based academic freestanding children’s
hospital ED serving a largely urban population), Children’s
Hospitals and Clinics of Minnesota Minneapolis (a private
but academic freestanding children’s hospital ED serving a
largely urban population), Children’s Hospitals and Clinics
of Minnesota St. Paul (a private but academic
freestanding children’s hospital ED serving a largely urban
population), and University of California, Davis Medical Center
(a university-based academic ED serving a largely urban
Patient and stakeholder engagement in the trial
Parents and other key stakeholders were engaged early on
in the design of this trial and will continue to be engaged
throughout the entire investigation; they will comprise the
Patient and Stakeholder Advisory Council (PSAC). The
PSAC consists of an ED Patient Advisory Council (PAC)
and a parent representative. The ED PAC consists of five
individuals who have contributed the patient’s perspective
to several practice and quality improvement initiatives at
the Mayo Clinic in Rochester over the years - a Masters
level ED quality specialist, three patients, and a nurse
representative. The ED PAC reviewed and provided feedback
on the study design and grant proposal and will continue
to inform on the conduct of the trial, interpretation of the
results, and dissemination of the study findings. The
parent representative, who both provides her own perspective
and serves as a liaison for the views of the ED PAC, has
experience as a parent of a child with minor head trauma
who was evaluated in the ED. The parent representative
assisted in the development and iterative refinement of
the Head CT Choice decision aid, provided feedback on
the grant proposal submitted for funding, selected the
primary outcome for the study, is an active member on
the investigative steering committee, and participates in
the study as a co-investigator.
Eligibility criteria and participant identification
Eligible participants will be parents seeking care for a child
or adolescent who is less than 18-years-old, has
experienced blunt head trauma (above the eyebrows and not
isolated to face or eyes) within 24 hours, and has at least one
of the PECARN risk factors for ciTBI (except for the two
higher risk variables of altered mental status or signs of
skull fracture) . Eligible clinicians will be attending
physicians, fellows, and midlevel providers caring for
children with minor head trauma. Children with signs of skull
fracture, GCS < 15 or other signs of altered mental status,
brain tumor, penetrating head trauma, bleeding disorder
or coagulopathy, ventricular shunt, pre-existing
neurological disease, syncope or seizure that preceded the head
trauma, transferred to the ED with imaging already
obtained, known pregnancy, or > 2 PECARN risk factors will
be excluded. Figure 1 displays the process of patient
identification and enrollment that will be used in the trial.
Given the risk of contamination when randomizing at
the patient level, we will randomize at the clinician level.
Randomizing at the clinician level will obviate the risk
of contamination associated with randomizing at the
patient level. To decrease the risk of contamination by
the sharing of information regarding the intervention
between clinicians, we will emphasize to participating
clinicians the importance of not sharing information about
the intervention with their colleagues during the
enrollment period. In addition, study coordinators will monitor
for contamination at the time of patient enrollment and
through review of the video recordings of clinician-patient
discussions. Clinicians will be dynamically randomized
and stratified  by site and by whether their primary
clinical training is in a pediatric specialty (pediatrics or
pediatric emergency medicine) or another specialty (such
as general emergency medicine, family practice, or internal
medicine). Informed consent to participate in the study
and have their clinical encounters audio and video recorded
will be obtained from clinicians at each site prior to
enrollment. After clinician consent is obtained, a statistician will
centrally randomize the clinician and communicate the
study arm assignment to the site principle investigator and
study coordinator. This centralized process will effectively
conceal allocation prior to randomization.
Participant identification and recruitment
Study coordinators will identify potentially eligible parent/
patient dyads based on a chief complaint related to head
trauma recorded at the time of ED registration and
communication with treating clinicians in real-time. Senior
resident physicians who often first evaluate the patient in
the settings in which the trial will be conducted will be
instructed to obtain the PECARN risk factors when
conducting the initial history and physical examination
and to not discuss the diagnostic options with the parent
(Figure 1). Once these data have been obtained, the
clinical predictors will be communicated to the study
coordinator to determine if the patient has at least one of the
(non-high-risk) PECARN predictors and meets all other
eligibility criteria. The study coordinator will record
these data on the eligibility assessment case report form
(Additional file 1). Once patient eligibility is confirmed,
study coordinators will obtain written informed
consent from the parent(s) and assent from the patient to
participate in the study and video record the discussion
with their clinician.
Development and refinement of the decision aid
A multidisciplinary research team including clinicians,
health service researchers, a graphic designer, a radiation
physicist, and patient representatives collaboratively
Figure 1 Flow diagram showing patient identification and enrollment in the flow of patient care. *Other signs of altered mental status include
agitation, somnolence, repetitive questioning, or slow response to verbal communication. **Clinicians will be randomized to decision aid or usual care
prior to patient enrollment. Parents will engage with their clinician according to the arm to which their clinician was randomized. ciTBI, clinically-important
traumatic brain injury; CT, computed tomography; ED, emergency department; GCS, Glasgow Coma Scale; PECARN, Pediatric Emergency Care
Applied Research Network.
developed the initial Head CT Choice decision aid.
Using methods we have employed to develop other
decision aids [13-17], we designed and refined Head CT
Choice through an iterative process that involved design
of an initial prototype, refinement based on the feedback
received, use of the prototype in simulated parent/patient
dyads in the ED setting, and use in ED clinical encounters
in the flow of patient care .
In the original PECARN minor blunt head trauma
study, only a summary estimate of the risk of ciTBI in
the moderate risk group (0.9% for younger than two
years and 0.8% for two years and older) was reported in
the published manuscript . To maximize the
granularity of risk estimates provided to parents, we obtained
the PECARN public use database  and calculated
the precise risk of ciTBI based on the presence of any
(non-high-risk) isolated PECARN risk factor (such as
vomiting) or the combination of up to two simultaneous
risk factors (such as vomiting and loss of consciousness).
For patients whose physicians are randomized to the
intervention arm, the clinician will be shown the specific risk
estimate for their patient, including the exact proportion
and 95% CI. In the case of a patient with two risk factors,
the clinician will be shown the risk estimate, exact
proportion, and 95% CI for each isolated risk factor and for the
combination of the two risk factors. Patients with more
than two PECARN risk factors (in addition to those with
either of the high risk factors) will be excluded from
enrollment due to the very few numbers and the higher risk
for these patients. In the trial, coordinators will select the
decision aid that corresponds to the risk for ciTBI of that
isolated risk factor or, in the case of two risk factors, the
highest risk estimate displayed.
In the process of decision aid development and
refinement the following themes consistently emerged:
(1) clarifying the differences between concussion and
TBI, given recent social media attention on concussion;
(2) communication of individual patient risk using natural
frequencies, a consistent denominator, a prose description
of the natural frequencies, and pictographs; (3) limiting
the amount of information to that which is relevant to
the decision at hand and best facilitates a conversation
between the parent and clinician without undue focus
on the decision aid itself; and (4) clearly outlining the
choice of a head CT scan during the ED visit, home
observation if no CT scan is obtained, or having the clinician
make the decision on the parent’s behalf.
The Head CT Choice decision aid (Additional file 2) is
a three-page paper tool that takes into account each of
these key themes in numerically ordered sections to
facilitate dialogue between the clinician and the parent.
The decision aid first graphically highlights key
differences between concussions and other types of
significant brain injuries and communicates the child’s risk
for ciTBI. The second page clearly outlines the decision
that is to be made (head CT scan in the ED versus home
observation) and educates the parent on the concerning
signs and symptoms of TBI and the indications for return
visit to the ED should they opt for home observation
without a CT scan. Next, a table compares the key advantages
and disadvantages of each management option and invites
the parent to circle the issues that are most important
to them. Finally, the decision aid outlines the three
management options: head CT scan in the ED versus
further observation at home with no CT scan, or having
the ED clinician decide on the parent’s behalf. It also
includes check boxes to document the decision along with
a reminder that they will have the opportunity to revisit
the decision with their clinician while in the ED. The
third and final page includes a space to provide a
contact phone number should the parent need to contact a
healthcare provider after leaving the ED.
Participating clinicians at each study site were invited to
attend a one-hour grand rounds lecture on the use of
the decision aid, which included a demonstration of the
tool. Clinicians randomized to the intervention arm will
also be provided with brief video clips demonstrating
use of the decision aid, which site principal investigators
will review with the participating clinicians and will also
be available for review at their convenience. Study staff
will also be available at the point-of-care to provide brief,
individualized re-training to clinicians on an as-needed
basis. They will also offer reminders of how to use the
decision aid when deviations in the quality of delivery
are observed in real-time or reviewed on the video
recordings of the clinical encounter.
For parent/patient dyads cared for by clinicians
randomized to the usual care arm, the clinician will discuss
the management options with the parent in that
clinician’s usual fashion. The clinician will not be given
access to the decision aid. The patient’s risk will be
calculated for study purposes, however, the patient and
clinician will be blinded to that patient’s precise risk of
ciTBI beyond that which is available in the peer-reviewed
literature . As in the intervention arm, the
clinicianpatient management discussion will be video and audio
recorded to assess the degree to which the clinician engages
the parent in the decision-making process and to monitor
for contamination in the control arm.
Parent and patient characteristics
We will assess parent’s preferred degree of involvement
in medical decision-making, literacy, and numeracy
(Additional file 3). Parent’s preferred degree of involvement
in decisions about medical treatment will be assessed
using the control preferences scale , a validated scale
that contains five pictorial representations accompanied
by a statement that depicts a continuum of styles ranging
from the patient making the decision independently, to
the patient and clinician making a shared decision, to
the clinician making the decision independently.
Patients will be categorized with regards to health literacy
in the following fashion: their literacy will be considered
to be inadequate if they respond to the specific
questions as either ‘not at all’ or ‘somewhat’ for confidence
in completing medical forms. Otherwise, they will be
considered to have adequate health literacy. Parent
subjective numeracy will be assessed immediately before use
of the decision aid using the validated Subjective
Numeracy Scale [21,22]. The scale is an eight-item questionnaire
that assesses parents’ comfort in working with numbers
on a six-point Likert scale. Parent demographics, including
the highest level of education and household income, will
also be obtained by self-report at the time of enrollment.
Detailed patient characteristics will also be collected at
the time of enrollment, including age, sex, race, ethnicity,
GCS score and the presence or absence of each of the
PECARN predictors at the time of enrollment.
Additionally, we will collect data on the course of the patient’s
symptoms in the ED (whether headache, vomiting, or
mental status changes developed or improved), whether
there were any concomitant substantial non-head injuries
diagnosed, how long the patient was observed in the ED,
whether a head CT scan or other imaging was obtained,
any findings on the head CT scan, ED length of stay, and
the patient’s type of departure from the ED (home or
A study coordinator will identify the primary clinician
caring for the patient at the time of enrollment and
collect data regarding whether they are a faculty physician,
fellow, or advanced practice provider (nurse practitioner
or physician assistant). The faculty physicians’ and fellows’
specialty training will also be collected (pediatrics, pediatric
emergency medicine, general emergency medicine, family
medicine, or internal medicine).
The outcomes were selected based on input from key
stakeholders, including parent representatives,
practicing clinicians, researchers (including shared
decisionmaking experts), and health policy decision makers. In
discussions with patient representatives it became clear
that knowledge of the risk of ciTBI and the advantages
and disadvantages of a head CT scan versus home
observation were of greatest importance and so parent
knowledge was selected as the primary outcome. All
other outcomes will be secondary outcomes.
We will assess parent knowledge by means of a post-visit
survey administered immediately after the clinical
encounter (Additional file 4). Eleven questions will assess parents’
knowledge regarding concussion, their child’s individual
risk of ciTBI, the available diagnostic options, the risks
related to radiation exposure associated with a head CT
scan, the potential for a CT scan to identify incidental
abnormalities that may require further investigation,
and reasons to return to the ED for re-evaluation should
their child’s symptoms or signs worsen after ED discharge.
We will measure the percent of knowledge questions
answered correctly and determine the mean difference
between knowledge scores for each study arm.
We will measure parental satisfaction in the way
information was shared during the encounter by asking five
questions using a seven-point Likert scale (Additional
file 4). For the analysis, we will classify satisfaction into
satisfied/very satisfied versus other responses.
Parent engagement in the decision-making process
We will measure the degree to which clinicians engage
parents in the decision-making process using the validated
Observing Patient Involvement in Decision-Making
(OPTION) scale [23,24]. The OPTION scale is an
instrument in which an independent observer views a
video recording of the clinician-patient interaction and
measures the extent to which a clinician exhibits twelve
behaviors on a four-point scale. OPTION scores are
transposed to a 0 to 100 scale for interpretation and
analysis, where higher scores indicate greater clinician
involvement of the patient. A proportion of encounters
will be calibrated in duplicate to ensure the
reproducibility of measurements.
We will measure the degree of conflict parents
experience using the validated decisional conflict scale (DCS)
(Additional file 4) [25,26]. The 16 items of the DCS are
scored on a 0 to 4 scale; the items are summed, divided
by 16, and then multiplied by 25. The scale is from 0 to
100, where higher scores are reflective of parental
uncertainty about the choice.
Trust in the physician
We will measure parents’ trust in their clinician using
the validated Trust in Physician Scale (Additional file 4)
[27,28]. There are 11 items with a scale of 1 to 5; the
items are summed, divided by 11, and then multiplied
by 100. The scale ranges from 0 to 100, where higher
values are reflective of higher levels of trust in their
We will assess patient safety by comparing the rate of
ciTBI in each study arm. We will define ciTBI as we did
in a prior study : death from TBI, intubation for more
than 24 hours for TBI, a neurosurgical procedure, or
hospital admission of two or more nights for the head
injury in association with TBI on a CT scan. Site
investigators, blinded to ED data, will verify outcomes by
health record review. CT scans will be obtained at the
ED clinicians’ discretion and interpreted by site faculty
radiologists. For outcome classification, a study pediatric
radiologist unaware of the arm to which the patient was
randomized will make definitive interpretations of
inconclusive CT scans. Study coordinators will contact
parents of children with minor head trauma by
telephone starting at seven days after the index ED visit to
ensure no outcomes are missed. Data from two cohorts
(with a combined total of more than 59,000 children with
minor head trauma [2,29]) indicate that no cases of
clinical deterioration due to delayed intracranial hemorrhage
occurred after 72 hours from the initial trauma, so we
are confident that the seven-day follow-up interval will
capture all potential adverse events.
Proportion of patients who undergo cranial CT scans
The decision to obtain a CT scan or not is the most
immediate clinical decision related to use of the decision
aid. The study coordinator enrolling the patient will
ascertain this in real-time and confirm the accuracy of
the data by health record review.
We will assess healthcare utilization for the seven days
following the ED visit. Healthcare utilization will include
measures such as hospitalization, re-hospitalization,
primary and specialty healthcare visits, and diagnostics
including CT scan and magnetic resonance imaging (MRI)
use. These measures will be obtained by health record
review, review of itemized hospital charges on the Universal
Billing form-92 and Universal Billing form-04 forms
(summary billing statements), and parental report at the
time of the seven-day follow-up telephone call. To assist
parents in collecting utilization data, we will provide a
form (Additional file 5) to document this information at
the time of discharge from the ED or the hospital. This
will allow for a more standardized collection of these
data elements if parents receive follow-up care at a
location other than the primary institution.
Clinician satisfaction will be assessed immediately after
the ED visit via a questionnaire regarding the helpfulness
of the decision aid and the clinician’s satisfaction with the
way information was shared on a seven-point Likert scale
(Additional file 6). For the analysis, we will classify
satisfaction into satisfied/very satisfied versus other responses.
We will assess clinicians’ preferred decision-making style
immediately after the visit using the validated control
preference scale (Additional file 6) . Frequencies and
counts of each pictorial selected by clinicians will be
reported along with correlation to the patients’ selected
pictorials from the control preference scale.
Accounting for a lost to follow-up rate as high as 5%
(based on a 2% rate we observed in our previous ED
SDM trial) , we anticipate enrolling and obtaining
outcomes on approximately 950 patients over the study
period with a 1:1 ratio between the intervention and
control arms. Rather than assume that patient outcomes
would be independent of the clinician treating them, we
assumed an intra-clinician correlation of P = 0.05 to
adjust for the clustering of patients when estimating
statistical power . Under this assumption, the anticipated
number of patients will provide the degree of power to
detect differences in each of the patient and
stakeholderimportant outcomes as specified in Table 1, using
twotailed tests and α = 0.05.
We will conduct the study according to the
intentionto-treat principle, including all parent/patient dyads in
the arm to which they were randomized, regardless of
whether they received the intervention assigned. We will
adhere to the CONSORT guidelines  to transparently
report study results and ensure that sufficient
information is included to allow for assessment of the study’s
internal and external validity.
We will compare outcomes between study arms using
t-tests for continuous outcomes and χ2 tests for
dichotomous outcomes, adjusted for clustering by clinician and
stratified by study site . If there are differences in
baseline characteristics between the two study groups, these
will be accounted for using hierarchical generalized
logistic or linear regression models that include an indicator
for study arm .
For the assessment of healthcare utilization, we will
compare utilization descriptively and using multivariable
models, using two-part or one-part generalized linear
Table 1 Sample size calculations
Outcome (n = 950)
Trust in the physician
Parent engagement in the decision-making process
Safety (clinically-important traumatic brain injury)‡
Proportion of children who undergo head CT§
Parent satisfaction with the decision made (% agree or strongly agree they are satisfied)
*Estimates were determined from our completed randomized trial for adult patients presenting to the emergency department with chest pain and are presented
as mean (standard deviation) or percentage.
†Lower decision conflict scores indicate less conflict experienced by patients related to feeling uninformed.
‡ Non-inferiority, one-sided test with alpha = 0.05 with a maximum difference of 2%. Baseline rates determined from the PECARN prediction rule study.
§ Obtained from the rate of CT scan in the moderate risk group of patients in the PECARN prediction rule study.
CT, computed tomography.
regression models. We will use the Park test to assess
the appropriate distribution, and use a two-part model
for outcomes where more than 10% of the subjects have
zero outcome measures. We will also analyze the results
using a subset of patients who primarily receive all of
their healthcare at the participating centers. We expect
this will provide a sensitivity analysis of the overall trial
results based on self-reporting.
We will perform descriptive analyses to describe any
potential heterogeneity of treatment effect (HTE) and
facilitate synthesis of subgroup results in future
metaanalyses. We will conduct descriptive HTE analyses by
age, gender, parent race/ethnicity, and highest attained
parental education level. The outcomes assessed with
HTE analyses will be the same as those assessed in the
trial. We will also conduct interaction testing to
determine the interaction between the decision aid and each
pre-specified patient characteristic.
We will make every effort to minimize the occurrence of
missing data. Items self-reported by parents at the
seven-day follow-up telephone call will attempt to be
verified (or ascertained, if missing) by medical record
and healthcare billing review. A study analyst will
conduct frequency reports every two weeks to identify and
obtain missing data. Patients with missing outcome data
will not be included in the assessment of that outcome.
Rates of missing data will be reported as well as known
reasons for missing data. For data used to adjust study
comparisons, we will use multiple imputation to account
for any data that are missing at random.
Safety and monitoring
An independent data and safety monitoring board
(DSMB) will monitor safety, scientific, and ethical
aspects of the study. The DSMB has already met (prior to
beginning enrollment) and will meet every six months
throughout the duration of the study. Though every
effort will be made to minimize post-randomization
exclusions, patients will be excluded if they are found to meet
exclusion criteria that were not recognized at the time of
enrollment or they choose to withdraw . Any
potential ciTBIs following discharge from the ED or hospital
will be reported to the principal investigator and the
DSMB. The authority to stop the study will be retained
by the DSMB and must be based on a consensus. The
study will not be monitored for early termination due to
benefit or futility.
We have described the methods employed to develop
and test the first decision aid for minor blunt head
trauma in children; Head CT Choice. With the decision
aid developed, we will conduct a multicenter
clinicianlevel parallel randomized trial to measure the
effectiveness of the decision aid on patient-centered outcome
measures, safety, and healthcare utilization in parents of
children with minor head trauma. In the context of prior
and ongoing work on the development and
implementation of the PECARN clinical prediction rules, the current
study informs and expands on the incorporation of
parental preferences, clinician experience, and other factors that
influence the decision of whether to obtain a head CT
scan in children at moderate risk for ciTBI. We anticipate
that the development and testing of a decision aid for use
in this moderate risk group will equip clinicians with the
tools needed to educate, empower, and engage parents
in the decision-making process. Use of this aid will also
facilitate risk communication, thus strengthening the
doctor-patient relationship in the context of an
emergency care interaction limited by time, the lack of
continuity of care, and the need for clinicians to provide
care for multiple patients simultaneously.
Given that we are randomizing at the clinician level,
there is some risk of contamination if clinicians
randomized to usual care get access to the decision aid and gain
experience with using it in clinical encounters with
parents of children with minor head trauma. We will take
several steps to minimize the risk of contamination.
First, we will emphasize to clinician participants the
importance of not sharing the decision aid with their
colleagues. We will also have study coordinators monitor
for this in the process of conducting the trial. Second,
using the PECARN public access dataset, we have
generated a calculator that provides individual risk estimates
for each of the isolated PECARN risk factors and for any
two risk factors combined, in addition to the exact
proportions and 95% CI’s. We have verified the accuracy of
these risk estimates with the principal investigator of the
PECARN head trauma study (NK), and these estimates
are not accessible to clinicians at the point-of-care.
Third, only the site coordinators will have access to
copies of the decision aid and clinicians will not be provided
a copy of the decision aid in the usual care arm. Fourth,
site coordinators will be carefully trained to confirm the
accuracy of each of the PECARN variables and to obtain
sign-off from the treating clinician, but to keep the
clinician blinded to the risk estimate for ciTBI unless that
clinician is randomized to the decision aid. Fifth, we will
make every effort to obtain video and audio data of the
discussion between the clinician and the patient
regarding whether to obtain a head CT scan during the
ED visit or to further observe their child at home in
both the intervention and control arms, and we will
monitor for contamination by review of these data.
Finally, if contamination does occur, we anticipate this
will bias the effect estimates in each arm toward the
It is likely that not all clinicians will be willing to
participate in the trial or have their discussions with the
patient to be video recorded. However, in previous (14)
and ongoing trials over 90% of the clinicians have agreed
to participate. In addition, we have >99% power to detect
the degree of difference in patient engagement in the
decision making process that has been observed on
video-recordings in prior trials, so we anticipate having
sufficient power to detect a difference in this outcome
measure even if some clinicians do not provide consent
Obtaining head CT scans in children at a very low risk
of TBI unnecessarily exposes children to the potentially
harmful effects of radiation and increases healthcare
utilization. Developing and testing the effect of a
patientcentered decision aid, Head CT Choice, in a pragmatic
multicenter clinician-level parallel randomized clinical
trial has the potential to more closely tailor CT use to
risk-informed parental preferences and improve the
experience of care for parents of children with minor
head trauma in the context of a busy and overcrowded
ED care delivery system.
Additional file 1: Head CT Choice eligibility assessment case report
form. CT, computed tomography; CSF, cerebral spinal fluid; DA, decision
aid; ED, Emergency Department; GCS, Glasgow Coma Scale; PECARN,
Pediatric Emergency Care Applied Research Network; VP,
Additional file 2: The head CT choice decision aid. The decision aid
(DA) first graphically highlights key differences between concussion and
traumatic brain injury to frame and focus the discussion on the risk for
traumatic brain injury. The DA communicates the child’s risk for traumatic
brain injury using a prose description of natural frequencies and a
pictogram (for children with a risk of clinically-important brain injury of at
least 0.5%, a pictogram of 100 will be used; for children with a risk of
clinically-important brain injury of less than 0.5%, a pictogram of 1000 will
be used). The second page clearly outlines the decision that is to be
made (head CT scan in the ED versus home observation with no CT scan)
and educates the parent in what to watch for and what should prompt a
return visit to the ED should they, in collaboration with their clinician, opt
for home observation. There is also a table that compares the key
advantages and disadvantages of each management option (speed of
diagnosis, radiation exposure, pharmacological sedation, cost, potential
downsides, and the likely duration of waiting in the ED) and invites the
parent to circle the issues that are most important to them. Finally, the
DA outlines the three management options (head CT scan in the ED,
further observation at home, or having the ED clinician decide on the
parent’s behalf) and includes check boxes to document the decision
along with a reminder to the parent that they will have the opportunity
to revisit the decision with their clinician while in the ED. The third and
final page includes a space to provide a contact phone number should
the parent need to contact a healthcare provider after leaving the ED.
Additional file 3: Parent pre-encounter numeracy and
decision-making preferences survey.
Additional file 4: Parent post-encounter survey.
Additional file 5: Patient healthcare services diary.
Additional file 6: Clinician post-encounter survey.
ciTBI: Clinically-important traumatic brain injury; CT: Computed tomography;
DCS: Decisional conflict scale; DSMB: Data safety and monitoring board;
ED: Emergency department; GCS: Glasgow coma scale; IRB: Institutional
review board; MRI: Magnetic resonance imaging; OPTION: Observing patient
involvement in decision-making; PAC: Patient advisory council;
PECARN: Pediatric emergency care applied research network; PSAC: Patient
and stakeholder advisory council; SDM: Shared decision-making;
TBI: Traumatic brain injury.
EH: conceived, designed, and obtained funding for the study, and drafted
and provided critical revisions to the manuscript. KW: wrote sections of and
provided critical revisions to the manuscript, contributed to the design of
the study. AK: contributed to the conception and design of the study and
provided critical revisions to the manuscript. JL: contributed to the design of
the study and provided critical revisions to the manuscript. PD: contributed
to the conception and design of the study, data analysis and interpretation
for the development of the PECARN risk calculator from the publicly
available dataset, and provided critical revisions to the manuscript. LT:
contributed to the design of the study by critically reviewing and refining
the decision aid and provided critical revisions to the manuscript. SW:
contributed to the design of the study by providing input on outcome
classification for cases of potential ciTBI and provided critical revisions to the
manuscript. JLH: contributed to the design of the study by participating in
the development of the decision aid and provided critical revisions to the
manuscript. LP: contributed to the design of the study by developing the
standardized data collection forms and surveys and provided critical
revisions to the manuscript. AL: contributed to the design of the study by
designing and refining the knowledge questions included in the parent
post-visit survey and provided critical revisions to the manuscript.
JW: contributed to the design of the study by representing a parent’s
perspective in developing and refining the decision aid and prioritization of
study outcomes and provided critical revisions to the manuscript.
KS: contributed to the design of the study by designing and refining the
decision aid based on parents’ and other stakeholders’ input and provided
critical revisions to the manuscript. NS: contributed to the conception and
design of the study by developing the healthcare utilization analysis, drafted
sections of the manuscript, and provided critical revisions the manuscript.
MB: contributed to the conception and design of the study by developing
the statistical analysis plan and study database and provided critical revisions
to the manuscript. JH: contributed to the conception and design of the
study by developing the statistical analysis plan, drafting portions of the
manuscript, and provided critical revisions to the manuscript. VM: contributed
to the conception and design of the study by defining key study outcomes and
providing insight into how to meaningfully engage parents, parent
representatives, and the ED patient advisory council in the study, and
provided critical revisions to the manuscript. NK: provided input on study
conception and design, ensured accuracy of analysis and interpretation of
the PECARN public access dataset in the development of the risk calculator
for ciTBI, assisted in iterative refinement of the decision aid, and provided
critical revisions to the manuscript. All authors read and approved the final
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