VAGABOND: a Mnemonic to Aid in the Memory Retention of the Canadian CT Head Rule
Condition: Traumatic Brain Injury; Education
MeSH terms: Brain Injuries; Brain Injuries, Traumatic
Study type: Interventional

Summary: 
      The aim of this study is to assess the effectiveness and usefulness of a simple one word
      mnemonic in the memory retention of the different components of the Canadian CT Head Rule
      (CCHR) in senior medical students and interns. The CCHR, a clinical decision rule used by
      emergency physicians to determine the need of head CT in the context of minor traumatic brain
      injury (mTBI). A rapid recall of the rule in the clinical setting would be expected to
      improve its utilization and overcome one of the barriers in its implementation. This would
      ultimately result in better utilization of resources and reduction in unnecessary exposure to
      radiation.
    

Detailed description: 
      Introduction

      Minor head injury is a serious public health problem. It is defined as a history of loss of
      consciousness, amnesia, or disorientation and a Glasgow Coma Scale (GCS) score of 13-15 [1].
      Patients with minor head injury are frequently encountered in the emergency department and
      the outpatient settings [2]. In the United States, it is estimated that each year there are
      about 1.2 million Emergency Department (ED) visits and 800,000 visits to the outpatient
      setting related to minor head injury [2]. Although most patients with minor head injury can
      be discharged without sequelae after observation, a small proportion deteriorates and
      requires neurosurgical intervention for intracranial pathology [3]. Therefore, early
      diagnosis of such injuries by computed tomography (CT) followed by early surgery is very
      important in the treatment of those patients. Therefore, when faced with such situation,
      clinicians have to make the decision whether further investigation in the form of CT imaging
      of the head is necessary to rule out an intracranial lesion. Not imaging a minor head injury
      could potentially lead to significant consequences if an intracranial pathology is missed. On
      the other hand, imaging all patients will lead to unacceptable exposure to ionizing radiation
      and waste valuable health resources.

      Clinical decision rules (CDRs) are tools that attempt to formally test, simplify, and
      increase the accuracy of clinicians' diagnostic and prognostic assessments. They guide
      clinicians, establish pretest probability, provide screening tests for common problems, and
      estimate risk [4]. A number of CDRs have been developed to guide clinicians dealing with
      minor head injuries on deciding whether CT scan of the head is indicated or not
      [1,5,6,7,8,9,10,11,12]. Among the multitude of CDRs, the Canadian CT Head Rule (CCHR) has
      been repeatedly shown to be useful with good sensitivity and specificity [13,14]. It was
      first developed and tested among 3212 patients with head injuries in 10 Canadian institutions
      between 1996 and 1999 and published in 2001[1].

      The CCHR consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected
      open skull fracture, any sign of basal skull fracture, vomiting ≥2 episodes, or age ≥65
      years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous
      mechanism of injury). The high-risk factors are 100% sensitive for predicting need for
      neurological intervention, and would require only 32% of patients to undergo CT. The
      medium-risk factors are 98·4% sensitive and 49·6% specific for predicting clinically
      important brain injury, and would require only 54% of patients to undergo CT [1].

      Despite its demonstrated validity, awareness and use of the rule remains low in many parts of
      the developed world, including Canada [15]. In fact there is evidence that implementation of
      the rule did not lead to a reduction in emergency department use of CT imaging and in some
      occasions there was actually an increase over time in use of CT scans [16]. Several barriers
      of implementation have been suggested. One of these is physicians' forgetting the details of
      the rule at the bedside [17]. Having a simple mnemonic that acts as a memory aid to the
      different components of the rule may help overcome this barrier. Mnemonics have been shown to
      enhance retention of clinical decision rules such as the Ottawa Ankle and Foot Rules [18].
      Therefore, this study proposes the hypothesis that a mnemonic to remember the CCHR will
      enhance retention of the components of this clinical decision rule by physicians and medical
      students.

      Method:

      This is a single-blinded randomized controlled trial to evaluate whether the use of a
      mnemonic would improve mid-term and long-term knowledge and retention of the CCHR. The
      participants will be interns and medical students from the Sultan Qaboos University and Oman
      Medical College. The study tool will be an online survey that will be emailed to all enrolled
      medical students in both institutions. The initial email will gather demographic and level of
      education of participants and their initial knowledge about the CCHR. Then participants will
      be randomized to receive either a table of the rule produced by the developers of the rule
      listing the CCHR and a second group will receive the mnemonic. The second email will measure
      the immediate retention of the rule. A follow up email six months after the randomization
      will assess the retention of the CCHR between the two arms of the study.

      The study will aim to recruit all interns and final year medical students. The study will
      require at least 150 participants in each arm in order to attain 95% power in detecting a 5%
      difference between variable of the two arms. Randomization will be done using a software
      program.

      The mnemonic VAGABOND will be used to enhance students' retention of the CCHR in this study.
      The mnemonic stands for:

      V for Vomiting more than 2 times A for Amnesia G for GCS less than 15 for more than 2 hours A
      for Age more than 65 years B for Basal skull fracture ON for OpeN skull fracture D for
      Dangerous mechanism

      The questionnaires are accessible on the following weblinks:

      https://docs.google.com/forms/d/1Q3EltuGLuedWJ6w7mzbXi8j4VXCW7vMnq6ThI-rAtVo/edit?ts=5b08ccb1

      https://docs.google.com/forms/d/17QbSQEWdqb97Qhlz2hA5gnAIMDcJkHB5bsK8EL4mG5s/edit

      Data will be directly entered into a pre-populated Statistical Package for Social Sciences
      (SPSS) datasheet. The study will present a descriptive analysis of all the variables
      collected. In order to assess the significance of differences in the variables between the
      two arms of participants, a series of Chi-Square tests and the Fisher exact tests will be
      used where appropriate. The Statistical Package for Social Sciences (SPSS) software will be
      utilized in the data analysis

      Implications:

      The study will assess whether the use of a mnemonic enhances the awareness of a clinical
      decision rule among interns and medical students. It will highlight the value of using simple
      mnemonics in teaching clinical decision-making. Such data is valuable for medical educators
      in other settings where critical clinical decisions can be made based on available rules.
    

Intervention name(s): Mnemonic; CCHR rule
Intervention type(s): Behavioral; Behavioral
Intervention description(s): A mnemonic used as a memory aid; A list of the CCHR items
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: Brain; Trauma; Medical education; Emergency department