Table 1 Summary of domains and specific beliefs

Domain

Specific Belief

Sample Quote

Frequency

Beliefs about capabilities

I am confident I can apply the Canadian CT Head rule

‘quite confident, strongly confident’ #6;

5/8

‘I think it is very easy’ #1;

‘quite confident’ #7

*Some of the criteria are not always clear for me

‘the mechanism which is sometimes a little confusing, the fall from elevation always confuses me as well as some of my colleagues’#1; ‘dangerous mechanisms I find that’s a bit vague sometimes’ #2; ‘over the age of 65 which is always a contentious one’ #3

4/8

*It is challenging/easy to follow the rule when the department is busy

‘I go and see the patient and they’ve already had a CT’#4; ‘even when we’re busy I think it’s something that could be done relatively briefly’ #7; ‘when I got too many patients and I am trying to thin things out I just can’t remember all the criteria’ #2

4/8

Beliefs about consequences

Use of the CT head rule supports my decision making

‘your decision making is validated by a clinical decision rule’ #5; ‘it gives you some confidence in your clinical decision-making’ #1; ‘helps me decide whether I need to accept a transfer’ #8

5/8

Use of the CT head rule decreases radiation exposure for patients

‘improves the radiation per patient’ #2; ‘needless radiation’ #3; ‘exposure to radiation is lower’ #4

5/8

*Use of the CT head rule improves/hinders patient flow in the department

‘it improves flow in the emergency department’ #1;’It would increase favorably our patient flow’ #7; ‘every time you get a CT head it adds another hour or two to the length of stay’ #1

7/8

The rule is used to explain to patients why they don’t need a head CT

‘often times we use it to explain to families why we’re not ordering a CT scan’ #3; ‘you can justify to them’ #5; ‘the first item is convincing patients they don’t need a CT’ #7

5/8

Behavioural regulations

*I rely on my own clinical judgment to guide my decision making when I am uncertain

‘concerned that they need a CT head, even though they don’t meet any of the criteria, I would still go ahead and do a CT head’ #2; ‘the category I take the most license with is the age category’ #8; ‘if I say “gee this isn’t making sense; I’m not comfortable” then I’ll do a CT scan’ #4

4/8

*The rule is not easily accessible to me

‘wall charts in assessments rooms that make it easily accessible’ #7; ‘access to resources that allow you to reference quickly’ #5; ‘having it more in my face in my department’#2

7/8

*Criteria in the Canadian CT Head Rule are flexible

‘we no longer use the rule, I mean that format’ #4;

4/8

‘may have a few minor criteria that differ a little bit, they are pretty much all the same in my mind’ #2; ‘I think there is huge variation in how the rule is used’ #8

Memory, attention, decision processes

*Criteria in the rule are easy/difficult to remember

‘I don’t know all the criteria off by heart’#2; ‘I probably remember most of them but there’s always one to two that I’ll miss’ #6

8/8

Patient presentation cues my use of the rule

‘as soon as I see you know, bonked on head, transient loss of consciousness’ #4; ‘prime mechanism of injury triggers the use of the rule’ #3

8/8

*I need to have the rule visible to remember to use it

‘when I do use the rule I have it in front of me’ #5; ‘so I want a piece of paper or you know something that will twig me’ #4

4/8

*Reminders to use the rule would be helpful

‘we need to have a reminder’ #4; ‘a tool reminder would be most helpful’ #6

5/8

*The number of criteria in the rule make it easy/difficult to remember

‘the limited number or short number of steps makes it easy’#1; ‘it’s too long unless you have it written down somewhere’ #2; ‘the rules are fairly brief and they don’t involve too many steps’ #7

5/8

Environmental context and resources

*The focus on patient flow influences my use of the rule

‘always under pressure to see more patients faster’ #2; ‘move them out the ED faster and free up a bed by getting a CT’ #8

5/8

*Ease of access to the CT scan discourages use of the CT rule

‘more CT scans because they are more and more readily available’ #8; “we have ready access to CT 24 hrs a day’ #2; ‘it’s a bronze day with all these solar powered CT scanners in all the community hospitals’ #4

5/8

*A busy department discourages/encourages use of the rule

‘being a busy ED it’s helpful to have one less thing to follow up on…probably encourages its use’ #3; ‘times when I have forgotten to use it when I’m just so busy’ #4; ‘when you are busy it’s hard to, you know, you have grounds to use it but it does slow you down’ #5

6/8

*Patient presentation may bias use of the rule

‘by the time they get to us they are in a different state’ #5; ‘sometimes you are biased by the location of the patient and you forget it may be a minor head injury’ #6

4/8

Social influences

*Patients emotional state influences my use of the rule

‘the only influence that would change my mind is the patient’ #4; ‘there are times when I’ve stretched the rules a little bit or you know because of a patient’s anxiety’ #1;’ if they are highly anxious and really want a CT’ #2

5/8

*Family’s emotions influences my use of the rule

‘at the younger age of the spectrum and there is a lot of family pressure or anxiety. It’s easy to get misguided by that’ #3

2/8

Talking about the rule with residents or other learners reinforces use of the rule

‘you spit out the rules all the time with residents so it is just there’ #3;

4/8

‘I go through the rule with referring physicians’ #6;

‘training physicians are always getting you to apply best practice’ #8

Domains UNLIKELY to explain response to implementation of Canadian CT Head Rule

Domain

Specific Belief

Sample quote

Frequency

Knowledge

The evidence that supports the rule is strong

‘it is a strong a piece of work as there is out there’ #4

7/8

‘there is very strong evidence that it is a sensitive rule’#8;

‘I would rate it as very strong’#7

Skills

You need experience as an emergency physician to use the rule

‘I think with some experience and some time they are easy to use’ #5;

5/8

‘I think you need a fair bit of background to pick out subtleties’#2;

‘every doctor who is an emergency physician has the skill set to use it’ #4

It is simple to use

‘It is simple and can be used by pretty much anyone’ #3;

6/8

‘the rule is simple as long as you have it in front of you’ #6

Social/professional role and identity

Use of the rule is a professional standard in emergency medicine

‘has pretty much become the standard of care’ #7;

6/8

‘your peers are doing it around the country’ #5;

‘I think it has become a standard of care’ #6;

Motivation and goals

The Canadian CT Head rule is important

‘it is very important because it provides a framework to follow’ #3

6/8

‘it’s a common presentation in our department and it’s a common referral we get from outside’ #6;

‘I am practicing current best evidence’ #8

Use of the Canadian CT Head Rule is compatible with my practice

‘Compatible because it’s a common presentation in our department, it’s a common referral we get from the outside as a referral centre so I think it’s a good tool to have’ #6;

7/8

‘Absolutely yes compatible’ #7

Emotion

Worry about missing an important injury is of concern in some situations

‘no clinical decision making rule is 100% so there is always a lingering worry’ #7; “the danger of missing a head injury is so high that people are just going ahead and ordering CT scans’ #8

3/8