Shameless self-promotion, regretfully.
To bias is to be human, and this is a nice review of some of our own intrinsic publication biases. It’s fun to get excited about a new biomarker promising more sensitive or specific identification of disease, promising to streamline our medical decision making. And then you get stuck with something like d-Dimer or BNP that gives us information people rarely use appropriately.
These authors pulled “highly-cited” articles evaluating biomarker utility, examined the reported findings, and then pooled the results of subsequent, larger follow-up studies and meta-analyses. 83% of their “highly cited” studies had effect sizes larger than the corresponding meta-analyses, and only 7 of the 35 biomarkers they reviewed even had RR estimates greater than 1.37 in the meta-analyses.
Jerry Hoffman likes to say on Emergency Medical Abstracts that if you just sit back and skeptically critique everything – you’ll end up being right most of the time. This article demonstrates just how frequently you’ll look smart by not getting overexcited by the most recent fantastic discovery.
“Comparison of Effect Sizes Associated With Biomarkers Reported in Highly Cited Individual Articles and in Subsequent Meta-analyses.”
This is an interesting systematic review of coronary computer tomography angiography that, I think, shows mostly that the endpoints for cardiology studies need to be re-evaluated. The conclusion that circulates in the new has been that positive CCTA was highly predictive of coronary events – patients with >1 segment of >50% stenosis on CCTA had an 11.9% annualized rate of coronary “events” when compared to the 1.1% annualized rate of patients without any >50% stenosis. This generates the 10.74 hazard ratio that has been circulating through the press releases trumpeting the predictive value of CCTA.
Unfortunately, this predictive value is a self-fulfilling prophecy because 62% of their “events” were revascularizations. If you subtract out the portion that went for revascularization, the remaining all-cause mortality, cardiovascular death, nonfatal MI, UA requiring hospitalization, that’s 5% annualized rate. Still higher than folks without any coronary stenoses at all, but you have to wonder – could we have predicted the population with a 5% cardiovascular morbidity risk without a CCTA? Does the management decision to perform revascularization confer upon this population a cardiovascular morbidity/mortality benefit? We are seeing a lot more in the literature showing that medical management is as advantageous as stenting, so, again, I’m not sure what the role of CCTA is – particularly from the Emergency Department.
“Meta-analysis and systematic review of the long-term predictive value of assessment of coronary atherosclerosis by contrast-enhanced coronary computed tomography angiography.”
This article got a ton of press – but it tries to take far too simple an approach to far too complicated an issue. I’ve done research like this, where you use zip code centroids and calculated distances to nearest hospitals, and it’s just one way a blind man describes an elephant.
These authors look retrospectively at all the acute MIs in four California counties, then looked at hospital daily diversion logs for each day from each of those hospitals – and tried to merge them together to prove that if your nearest hospital was on diversion for a lot of the day you had your acute MI, you had worse outcomes.
Their final analysis says, basically, there’s a 3-5% difference in 30-day, 90-day, and 1-year mortality if your nearest hospital is on diversion >12 hours in a day vs. if your nearest hospital is on diversion <6 hours per day. The between 6-12 hour diversion cohort performed identically to the <6 hour per day cohort. So, I don’t know exactly what to make of this. Their 95% CI almost crosses zero. Something magical happens at 12 hours that changes your acute MI mortality risk. So, yes, what the authors are trying to prove is probably true – but this article’s data mining and massage can only hypothesize the association, and doesn’t prove anything.
“Association Between Ambulance Diversion and Survival Among Patients With Acute Myocardial Infarction.”
I was asked to blog about this little article – since it lies at the intersection of Emergency Medicine and informatics.
The problem – the most difficult clinical situations are the ones where we need a handy decision tool – and the hardest to come up with an effective one. Syncope rules, PE prediction rules, ACS prediction rules, and now TIA evaluation.
The most important number to come out of this paper is probably 1.8% – the number of patients with a TIA who went on to have a stroke in the next seven days. That’s 38 out of their 2056 patients enrolled. The next number is 2.7%, which is the 56 patients who had another TIA within 7 days. So somehow a rule has to magically pick out that tiny proportion of patients who are going to have bad outcomes without excessively testing the remaining supermajority.
Nearly everyone had a CT of the head, nearly everyone had an EKG, very few (15% with an ABCD2 score ≤ 5 and 22.% with a score > 5) had consultation with a neurologist, and even fewer were admitted. The specificity for stroke within 7 days with a score >2 – the AHA definition of “high risk” – is only 12.5%. Not only that, but there was significant disagreement between enrolling physicians and the study center regarding the correct ABCD2 score for a patient.
So, in the end, ABCD2 is difficult to apply and only minimally useful. You’re going to miss half the strokes at 7 days if you apply it in a situation where the specificity is >50% – so, sure, a sky-high score tells you they’re in trouble, but that still doesn’t help you discharge the majority of your TIAs safely for outpatient follow-up.
“Prospective validation of the ABCD2 score for patients in the emergency department with transient ischemic attack.”
I’ve seen surfactant administered for alveolar collapse following near-drowning, but this is a case report regarding surfactant use in severe pneumonitis after low viscosity/low volatility lamp oil. Less than 1mL of similar aspirated hydrocarbons may result in significant lung injury. In their specific case they administered 80 mL/m2 of surfactant intratracheally as rescue therapy when their patient continued to become hypoxemic despite recruitment maneuvers on mechanical ventilation.
Definitely something to keep in mind depending on the pathophysiology of the lung injury.
“Early administration of intratracheal surfactant (Calfactant) after hydrocarbon aspiration.”
Now that increasing numbers of children are overweight and obese (up to 36% of 10 to 17 year olds now), 53% of this pediatric sample from West Virginia fell out of the Broselow tape estimate based on height. Of these, 77.1% of the incorrect weights were greater than that predicted by the Broselow.
It is West Virginia – not the healthiest state in the U.S. – but any hospital that serves a predominantly disadvantaged population may have similar results, and should realize that they may be under dosing their medications. The authors suggest only a couple alternative strategies, but I think we’re probably just best off using clinical judgement as to whether the tape is accurate in each individual clinical situation.
“Is the Broselow tape a reliable indicator for use in all pediatric trauma patients?”
Anyone working in the Emergency Department knows that homelessness and psychiatric disorders go hand-in-hand – and that also goes psychiatric disorders and substance abuse. This study confirms what we already know about the prevalence of these issues in the homeless population.
The most interesting number I read out of it was that the life expectancy of a homeless male aged 15-24 years was 38.7, and 47.4 for similarly aged homeless females – compared to life expectancies of 60.3 and 64.8 in their general population. It makes me wonder how much of that life expectancy difference is just the homelessness, or whether it’s the psychiatric and substance abuse disorders – I would probably say most of that difference is made up with the substance abuse.
“Psychiatric disorders and mortality among people in homeless shelters in Denmark: a nationwide register-based cohort study.”
I am torn regarding whether 82% represents appropriate performance on history taking in pediatric adolescent (ages 14 – 19) lower abdominal pain/dysuria/vaginal complaint, or whether that remaining 18% represents potentially uncaptured pathology. Considering that 76% of patients asked regarding sexual history reported sexual activity, and 83% of their subgroup completing anonymous questionnaires reported sexual activity, I think >90% enquiry regarding sexual activity would be a better target.
So, we’re doing a pretty good job – but it could be better.
“Sexual history documentation in adolescent emergency department patients.”