Four minute mull: Concussion, policy and awareness

09 Jan 2018 Posted by

Today’s fourminutemull today is a continuation of the concussion theme that I raised in Episode 2 last week.  I wanted to share with you some additional points, that I think are quite important to this subject

Specifically, I wanted to circle back to a graph that I used in that Episode to argue for why it’s so important for us to drive changes in the sport that will reduce the concussion risk.  That graph showed a large increase in concussion incidence over the last decade in professional rugby, but that in itself is not all bad news.  In fact, it’s an ironic success story, because the increase says more about the earlier under-diagnosis of concussion than it does about an actual increase in the risk of a concussion.

At least, that’s one theory.  In this video, I want to share with you some background to the concussion issue, and how that was, at least in part, solved through the use of policies that created time and space for doctors to make better diagnoses, and by driving education and knowledge into the sport.  What I think was especially key is that as the education and knowledge improved, the policy was adapted to include it.

The result is that now, Rugby has a pretty clearly defined head injury protocol, built around the Head Injury Assessment (HIA) protocol.  The HIA is a three-point-in time protocol, that begins when a player is suspected or seen to experience a head injury on the field.  Many of you have watched rugby and seen a player leave the field for what is a 10-min assessment inside the stadium, away from the noise, and perhaps you think that is all the HIA entails.

It’s actually a lot more complex and detailed.  It actually begins before the player leaves the field, because there is a list of eleven signs or symptoms that immediately confirm a concussion has occurred.  These are called “Criteria 1” signs and if a player has them, they must be immediately and permanently removed from the field – no assessment or further evaluation is necessary.  You can see these eleven Criteria in the video above.

Only if these eleven signs are absent, but there is still suspicion of a concussion, does the player actually have that sideline assessment.  If they pass that, then they can return to the field.  Fail it, and they’re forced off with a diagnosed concussion.

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Implications

There’s an interesting implication to all this.  When the HIA was introduced, it created time and space, and formalized a process by which concussion would be diagnosed.  This has the effect of basically “lowering the diagnostic threshold” for a concussion.  It makes it more likely that concussion will be identified and diagnosed, which is good, because then it can be treated.

However, that HIA is obviously not perfect.  Sometimes the Criteria 1 signs are missed – a player loses consciousness or is ataxic, but the medical personnel and match day doctor don’t see it.  Think George North, those of you who follow rugby.  Sometimes a player who is concussed can pass the HIA sideline assessment – this is a false negative, and obviously we need to improve the tool to ensure that this doesn’t happen.

However, when those ‘mistakes’ happen, and there is controversy around a player who seems or is concussed and keeps playing, a lot of people call for the abolition of the HIA.  They say it is “useless” and ineffective, and that we shouldn’t use a flawed tool for the decision-making process.  They would rather that any player with suspected concussion be immediately removed from play.

All good, in theory, but I hope that when you watch the video above, you will appreciate what this might cause.  If you do away with the HIA protocols, and you immediately and permanently remove any player with a head injury, you are going to increase the diagnostic threshold.  You will make it very unfavourable for the player and the team to ever acknowledge that a head injury is occurred.

And while some would remain obvious, there will be many head injuries that are thus not disclosed or acknowledged, and so the percentage of concussions that go undiagnosed would go up again!  Therefore, we need to be careful about making what seem to be theoretically conservative changes, because their outcome might be exactly what you don’t want.

A work in progress

Finally, I offer all this not to argue that rugby has a perfect system.  As you’ll see in the video, we still have 8% of concussed players returning to play or continuing to play.  The HIA sideline assessment does produce false negatives.  In fact, one of my big work projects this year is going to be to evaluate the HIA Protcol, because World Rugby now has a database of thousands of HIA cases and we know exactly why the player was taken off the field, how they fared in the 10-min sideline assessment, whether they returned to play.

So some good analysis can be done on that, including the important issues of sensitivity (does the HIA produce false negatives?) and specificity (does the HIA produce false positives?)  Both are bad, for different reasons.  The former means concussions are missed, the latter means they’re falsely diagnosed and that undermines confidence in the tools.  The early evidence suggests that the sensitivity of the sideline assessment alone is in the 80-percent range.  That means that around 15 in 100 cases of a concussed player will pass the test – the so-called false negative.  Of course, that needs to improve, but it’s also not so low as to be an ineffective test, as many have tried to argue.

When you add the Criteria 1 signs to the protocol, by the way (as you should), then the sensitivity of the entire HIA process jumps into the 90% range, which is actually very good as far as diagnostic tools go.  The specific numbers are going to the subject of some work this year.  I’ll keep you posted.

In any event, the point is that the system is imperfect, and evolving, and I hope that in future, the process can be improved.  The video above is necessarily superficial, but in time, we can look at exploring the issues in depth, so stay tuned!

Ross

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