Should We Be Asking: ‘Are They on Blood Thinners?’
Dr. Shenvi: One of the interesting trends related to warfarin and the DOACs vs no anticoagulant is that as you mentioned, Dr Shih, the first question out of people’s mouths or the first piece of information emergency medical services gives you when they come in with a patient who’s had a head injury is, “Are they on blood thinners or not?”
Yet, the paradigm is shifting to say it’s not actually the blood thinners themselves that are giving older patients the higher risk for bleeding; it’s age and other comorbidities.
Certainly, if you’re on an anticoagulant and you start to bleed, your prognosis is much worse because the bleeding doesn’t stop. In terms of who has a bleeding event, there’s much less impact of anticoagulation than we used to think. That, in part, may be due to the change from warfarin to other medications.
Some of the experts I’ve talked to who have done the research on this have said, “Well, actually, warfarin was more of a marker for being much older and more frail, because it was primarily prescribed to older patients who have significant heart disease, atrial fibrillation, and so on.” It was more a marker for somebody who is at risk for an intracranial hemorrhage. There are many changes that have happened in the past 10 years with medications and also our understanding.
Challenges in Patient Follow-up
Dr. Glatter: That’s a great point. One thing, Rich, I want to ask you about is in terms of your proxy outcome assessment. When you use that at 14 and 60 days with telephone follow-up and then chart review at 60 and 90 days (because, obviously, everyone can’t get another head CT or it’s difficult to follow patients up), did you find that worked out well in your prospective cohort study, in terms of using that as a proxy, so to speak?
Dr. Shih: I would say to a certain extent. Unfortunately, we don’t have access to the patients to come back to follow up all of them, and there was obviously a large number of patients in our study.
The next best thing was that we had dedicated research assistants calling all of the patients at 14 days and 60 days. I’ve certainly read research studies where, when they call them, they get 80%-90% follow-up, but we did not achieve that.
I don’t know if people are more inundated with spam phone calls now, or the older people are just afraid of picking up their phone sometimes with all the scams and so forth. I totally understand, but in all honesty, we only had about a 30%-35% follow-up using that follow-up pathway.
Then the proxy pathway was to look at their charts at 60 and 90 days. Also, we looked at the Florida death registry, which is pretty good, and then finally, we had both Level I trauma centers in the county that we were in participating. It’s standard practice that if you have an intracranial hemorrhage at a non–Level I trauma center, you would be transferred to a Level I trauma center. That’s the protocol. I know that’s not followed 100% of the time, but that’s part of the proxy follow-up. You could criticize the study for not having closer to 90% actual contact, but that’s the best we could do.
Dr. Glatter: I think that’s admirable. Using that paradigm of what you described certainly allows the reader to understand the difficulty in assessing patients that don’t get follow-up head CT, and hardly anyone does that, as we know.
To your point of having both Level I trauma centers in the county, that makes it pretty secure. If we’re going to do a study encompassing a similar type of regional aspect, it would be similar.
Dr. Shenvi: I think your proxies, to your credit, were as good as you can get. You can never get a 100% follow-up, but you really looked at all the different avenues by which patients might present, either in the death registry or a Level I center. Well done on that aspect.