Table 2.

Determinants of evidence-based practice in severe TBI

General determinants of severe TBI management
TDF domain and associated themes	Illustrative quotesa
Environmental context and resources
Academic institutional resources	“In a quaternary academic center, there is a focus on academic pursuit and evidence-based practice, and there’s regular review, there’s ongoing peer review, there’s ongoing audit, there's ongoing quality improvement initiatives, people are primed.” (IC01)
Practice audits	“The first thing we did was a survey…to figure out what [TBI] practice was, [and] it was terrible.” (NC02)
Local engagement with research	“It’s certainly an enabler, the degree to which a department is engaged in the research process, broadly and specifically, with respect to TBI.” (IC08)
Policy environment	“There’s an awful lot of patients in the USA that are getting [guideline-adherent care] only because it’s essentially a requirement to be a level one trauma center.” (NC06)
Availability of interventions	“Making it harder to provide an intervention that might not be recommended by the group…certainly would be more useful than writing a lot of guidelines that people may not consult.” (IC07)
Social influences
Collaborative decision-making	“I like talking to my colleagues and talking things over. They have expert knowledge that I don’t have.… A shared model [of care] is undoubtedly the best.” (IC08)
Organizational culture	“I think there needs to be a mutual respect as well as a partnership for what each specialty can offer in terms of advice, opinion, and direction of management.” (NC03)
Beliefs about consequences
Nihilism	“All the interventions we’ve had over the past 20 years, whether it’s hypothermia, decompressive craniectomy, they’re all dangerous processes, and they don’t make you better.” (NC04)
Alignment of metrics	“We always need to identify the issues that can improve our KPIs because we no longer are just looking at survival.” (NC09)
Behavioral regulation
Countering dogma	“I suppose they just had done it their way for so long…they would still be doing it, whatever the trial showed.” (NC03) “I’m not going to use it unless I have some idea…of how it works.” (NC02)
Ease of implementation	“The more complicated TBI interventions are more challenging from that point of view to translate because of the implementation education resources that are required, or the effort that’s involved to change practice.” (IC01)
Social/professional role and identity
TBI not a popular subspecialty	“Traumatic brain injury is not really seen as a route to academic promotion, publications, it’s just not seen as a sexy type of thing for a young and upcoming surgeon.” (NC05)
Knowledge
Mixed perspectives on CPGs	“I think everybody has that experience where you read a guideline and then you actually look up the reference, either discover that the paper that that sentence is based on is very weak or it doesn’t seem to have anything relevant.” (IC05) “It’s really easy to find a reason to do something different.…It’s very rare you have a perfect patient that is described in a perfectly designed trial.” (IC11) “The translation of research findings in the guidelines is very haphazard…it can be years and years and years before [a new finding is] adopted, and incorporated into practice.” (IC04)

Determinants of intravenous fluid resuscitation practice
TDF domain and associated themes	Illustrative quotesa
Environmental context and resources
Policy environment	“Probably the most effective facilitator of the implementation of that particular piece of evidence was now a requirement, where the blood bank will only release albumin when there’s a consent to the administration of blood products.” (IC03)
Social influences
Key opinion leaders	“Getting this information from people like [local champion], huge mentor early on, quickly changed practice. I certainly haven’t prescribed albumin since.” (TC03)
Knowledge
Awareness of evidence	“I think that there was a study from long time ago, I have to look it up, that looked at colloid versus crystalloid.” (NC09)

Determinants of decompressive craniectomy practice
TDF domain and associated themes	Illustrative quotesa
Beliefs about consequences
Craniectomy improves ICP but not long-term outcomes	“If it’s an older patient, who’s got a lot of comorbidity then it’s…not really an appropriate intervention.” (IC01) “If you perform a craniectomy on day two and it gets the patient out of ICU on day five.… We’re looking at perhaps an intervention that’s going to help us in the short-term but may not help in the long-term.” (NC01)
Social influences
Cultural context	“We are in a Catholic culture, so only God can take off your life. This is our culture. So it’s difficult to discuss with family because whenever you say I have 1% of possibility, they want 1%.” (NC07)
Emotion
Emotional pressure	“It’s just really hard if you’re looking at a patient and a family and you know that if you don’t do the decompression, the patient is probably going to die, it’s very hard not to do it even if you know that [the evidence] is suggesting there’s going to be a bad outcome. It’s hard to withhold life-saving care, and I think that motivates an awful lot of us.” (NC06)
Social/professional role and identity
TBI is becoming an ICU specialty	“Whenever we really [appropriately manage] in ICU our patients, the number of decompressions is reduced to a minimum.… Our intensivists don’t leave us many cases with intracranial pressures persistently over 25.” (NC07) “We’ve gone from a very active approach, to much more passive one.” (N01) “In Europe…the primary responsibility for the decision-making remains with the intensivist.” (NC10)

CPG clinical practice guideline, IC intensive care consultant, ICP intracranial pressure, ICU intensive care unit, KPI, xxx, NC neurosurgery consultant, TBI traumatic brain injury, TC trauma consultant, TDF Theoretical Domains Framework

^aSome quotations have been edited for readability, including addition of text in brackets, without alteration to meaning