Category Archives: Gastro

Glasgow Blatchford Score 2 – The case for an RCT!

Thanks for a great post, Gareth.  If you’ve landed here without reading that post, hit the link – this is a follow on, a ‘deep dive’ in the words of Smart EM – to be taken in the context of Gareth’s main post.

This is a landmark study in Emergency Medicine and gives us something useful that could reduce admissions.  With a critical appraisal hat on, however, I do think it’s important to point out a few flaws in the methodology.

Methodology of the Lancet study

The authors have essentially prospectively evaluated the performance of the GBS at several centres by reviewing case notes of patients presenting with upper GI bleed.  They then prospectively implemented the GBS, discharging patients with GBS of 0 and found that it was safe and reduced admissions.  It sounds pretty good, so why is there a problem?

The issue is that there’s no control group in the implementation phase.  When clinicians are told to use a tool that enables discharge of low risk patients, they may decide to use it in particularly low risk patients, who they’re happy to consider early discharge for.  There’s some evidence that this actually happened, as the proportion of low risk patients is greater in the implementation phase (22% vs. 16%) and the overall number of patients is enrolled is greater in the implementation phase (572 vs. 334), despite the overall recruitment period being shorter.  This is the classic problem with simple before and after analyses, and it makes the comparison of admission rates before and after implementation subject to substantial bias.

What’s more, there’s the issue of resource utilisation.  In the derivation phase, 96% of patients were admitted compared to 71% after implementation, which is great.  However, the median length of stay didn’t change (2 days in each group) although the mean length of stay reduced.  This suggests that the patients we’re avoiding admission for after implementation of the GBS would have had a short length of stay anyway (<2 days), so the reductions in length of stay are occurring in that group.  That’s still OK – so far, we’re still on to a cost saving and patients get to go home earlier.

However, you also have to consider that the low risk patients who were discharged were all given outpatient endoscopies and outpatient follow-up.  OK, only 40% actually attended for the endoscopy.  But what we don’t know is how many of them would have undergone endoscopy and out-patient follow-up with standard care – it may well have been less than 40%.  What’s more, using the score might tempt physicians to over-investigate or over-treat those who aren’t in the low risk group.

Overall impact on resource utilisation

It’s therefore possible that implementation of this protocol actually leads to a rebound overuse of resources.  To get a better idea of whether this actually happens, we need a control group.  The most obvious way to do that is to run an RCT.  Patients could be individually randomised to care guided by the GBS or standard care, or we could use cluster randomisation (e.g. randomise each centre to deliver care guided by one intervention or the other).  Alternatively, we could use a stepped wedge design, whereby we enrol a number of centres and all of them sign up to implementation of the GBS-based protocol.  Each centre is given a randomly allocated implementation date.  We then run a before and after analysis to evaluate admission rates and overall resource utilisation.  This is still a before and after analysis, but we have contemporaneous control groups at different centres.

What’s a Service Evaluation?

There’s a final point to make here.  The implementation phase was a service evaluation.  What does this mean?  Essentially, two centres implemented the protocol in practice and audited what happened.  They didn’t get consent from patients.  (They didn’t need it for this type of work).  However, it does mean that they couldn’t actually follow patients up as they would in a research study.  That means that the 60% of low risk patients who failed to show for their endoscopy went out into the ether.  They could have attended other hospitals for further care, perhaps because they were disgusted at being inappropriately discharged!  They may have undergone intervention at those centres – we just don’t know with this design.

The bottom line for clinical practice

Does this stop us from using the Glasgow Blatchford score?  No, excepting a few methodological flaws I think these authors have, on the whole, shown its safety.  I think we can use it.  Even NICE says we can use it!  We shouldn’t be so confident about the overall impact on resource utilisation though, as we just haven’t shown that in this study.

Glasgow Scores… Not just for coma any more!

Quick post…

NICE have recently published new guidance on Upper GI bleeding.

It is surprisingly sensible. I was pleased with their position on PPI’s for upper GI bleeding (not before endoscopy…).

The other point that I was happy to see was the inclusion of the Blatchford score for risk assement of these patients.

We all love a good scoring system, especially if really complicated (long hours spent working out APACHE scores on ICU spring to mind)

The Blatchford score however, is simple, and useful. I have been using this to help plan management of these patients for a while, and I was surprised to find that many people have not heard of it.

So what else to do? To the Bat Cave St Emlyn’s!

What is it?

To give it its full name; The Glasgow Blatchford Score was derived in 2000. It is designed to identify patients who require admission for treatment of their UGI bleed, and who can go home for outpatient management.

Previous to this, standard practice was to admit the mass majority of these patients, even the young well ones with minor bleeding or ‘coffee ground’vomits.

Here it is:

It can be easily calcualted using information availble in the ED. You can use the ever useful mdcalc.com

So why use it? 

So we can send people home! This has to be a good thing, as long as it is ‘safe’ to do so.

In 2009 Stanley et al performed a prospective study to establish whether this was the case. Their hypothesis: If the GB score was 0, the patient could go home from the ED, and be followed up as an outpatient.

Sounds great right? Did it work?

The study was split into two parts. First they collected data on all GI bleeds seen in the ED. They recorded the outcomes, and compared the outcomes with the GB score on admission. In the second part they introduced the low risk criteria, and discharged those with a GB score of 0.

So….

In the first part they identified 334 patients with UGI bleed. 319 of them got admitted (96%)

53 of them were low risk (GBS 0). 50 of these were admitted. None of them died or needed any interventions.

So far so good yes? If we could have have sent those patients home, wouldn’t everyone be happier and the world a better place?

So that’s what they did. In the second phase of the study they put their theory in practice. They identified 491 UGI bleed patients. 123 (22%) of them presented with a GBS score of 0, and of this group, 84 got sent home (68%).

They then followed them up to see how they got on. Only 23 (40%) turned up for their outpatient endoscopy, the rest were chased up via GP, case note review and telephone follow up.

So how did they do? Really well as it turns out. Out of the 123 patients with a GBS score of 0 a total of 0 needed an intervention or died from a UGI bleed related cause in the following 6 months. Zero, zilch, nada.

These results are summarised here:

For those concerned with our limited health resources (i.e. all of us), the exciting figure is at the bottom. Before the scoring system was introduced, only 4% of the UGI bleed patients were being discharged from the ED. With the scoring system in place, 29% were sent home.

Considering the numbers of these patients we all see, this is a big deal.

So should we do this? I think so.

Gareth.