Month: September 2014

Appropriate Resource Utilization Can Be Taught!

At least, that is the implication of this paper – and even though it’s probably not the most reliable demonstration of such an effect, its observations are likely valid.

This is a very convoluted study design aiming to comment upon whether residents trained in “conservative” practice environments differed from residents trained in “aggressive” practice environments.  However, “conservative” and “aggressive” were defined by utilizing a Medicare database to calculate the “End-of-Life Visit Index”.  Residents trained in a region where elderly patients received greater frequency of inpatient and outpatient care at the end-of-life were judged to have trained in an “aggressive” environment.

Then, to measure whether residents themselves had tendencies towards “conservative” or “aggressive” management, the authors reviewed American Board of Internal Medicine board certification examination questions.  Questions regarding management strategy were divided into “conservative” or “aggressive” strategies, based on the correct answers.  Finally, examinees were measured on how many correct and incorrect answers were provided on these questions featuring the two management strategies.  Correlating these test answers with the end-of-life environment presumes to measure an association between training and practice.

After all these calisthenics – yes, residents training in the lower-intensity environments were more likely to perform better on the “conservative” management questions.  Thus, the authors make the expected extrapolation: trainees apparently learn to mimic inappropriately aggressive care.

This is probably true.  Whether this study – with its limitations and surrogates – adequately supports such conclusions is another matter entirely.

“The Association Between Residency Training and Internists’ Ability to Practice Conservatively”
http://www.ncbi.nlm.nih.gov/pubmed/25179515

Patient Satisfaction: It’s Door-to-Room Times (Duh)

As customer satisfaction becomes rapidly enshrined as our reimbursement overlord, we are all eager to improve our satisfaction scores.  And, by scores, I mean: Press Ganey.

So, as with all studies attempting to describe patient satisfaction, we unfortunately depend on the validity of the proprietary Press Ganey measurement instrument.  This limitation acknowledged, these authors at Oregon Health and Science University have conducted a single-center study, retrospectively linking survey results with patient characteristics, and statistically evaluating associations using a linear mixed-effects model.  They report three survey elements:  overall experience, wait time before provider, and likelihood to recommend.

Which patients were most pleased with their experience?  Old, white people who didn’t have to wait very long.  Every additional decade in age increased satisfaction, every hour wait decreased satisfaction, and there was a smattering of other mixed effects based on payor source, ethnicity, and perceived length of stay.  What’s interesting about these results – despite the threats to validity and limitations inherent to a retrospective study – is how much the satisfaction outcomes depend upon non-modifiable factors.  You can actually purchase patient experience consulting from Press Ganey, and they’ll come teach you and your nurses a handful of repackaged common-sense tricks – but I’m happy to save your department the money:  door-to-room times.

Or change your client mix.

Done.

“Associations Between Patient and Emergency Department Operational Characteristics and Patient Satisfaction Scores in an Adult Population”
http://www.ncbi.nlm.nih.gov/pubmed/25182541

Still Adrift in Ignorance Over Blood Cultures

While supervising residents, one of the frequent diagnostic suggestions in undifferentiated febrile patients is: blood cultures.  As an Emergency Physician, the utility of blood cultures – short of diagnosing endocarditis or another primary hematogenous source – is vanishingly small.  After all, the source of infection is nearly universally somewhere else – lung, urine, CSF, skin & soft tissue – and relying on the blood to give you the answer two days later is an unreliable and impractical proposition.

This study is yet another attempt at identifying patients with high likelihood of bacteremia, retrospectively analyzing 5,499 patients at Odense University Hospital for whom blood cultures were drawn.  This cohort, representing roughly half of all patients presenting to the Emergency Department, had positive blood culture results 7.6% of the time.  CRP, temperature, and SIRS criteria were evaluated as potential predictive variables – and, unfortunately, the positive likelihood ratios of each were only between 2 and 3, and the negative likelihood ratios associated with each were all 0.4.  The authors combine these criteria and promote their absence as a rule-out, with a negative predictive value of 99.5% – but, common sense ought obviate trying to diagnose bacteremia in an afebrile patient with no SIRS criteria, and the NPV performance is more related to the low prevalence of disease than the utility of their criteria.

Really, the most interesting element of this study: the massive volume of blood cultures performed, with 92% of them true negative or false positive.  Costs for blood cultures vary by facility, and range from $15-$50, with patient charges typically a significant multiplier beyond.  A low yield might be important if the diagnoses were changing management and improving outcomes, but the vast majority of culture results are clinically unimportant.  These authors have not described particularly strong positive predictors – but they’ve illustrated the massive scope of the problem.

“How do bacteraemic patients present to the emergency department and what is the diagnostic validity of the clinical parameters; temperature, C-reactive protein and systemic inflammatory response syndrome?”

Early P2Y12 Antagonists Just Don’t Seem Useful

When undergoing an early invasive strategy for myocardial infarction, the guidelines and trials typically support dual platelet inhibition.  Most commonly, this regimen consists of aspirin and clopidogrel.  However, the P2Y12 receptor antagonists ticagrelor and prasugrel have been promoted as options due to incremental increased platelet inhibition over clopidogrel.  The theoretical benefits of early dual platelet inhibition include spontaneous lysis and prevention of re-thrombosis, as well as decreased early in-stent thrombosis.  Unfortunately, the ACCOAST trial demonstrated early prasugrel was associated only with increased bleeding and no associated cardiovascular endpoint benefits.

Now we have ATLANTIC, with a similar treatment strategy, utilizing ticagrelor.

Which is also negative.

Negative for the “co-primary” endpoints of ST-segment resolution or pre-PCI TIMI flow grade, at least.  The authors, however, focus on two other endpoints: bleeding, and in-stent thrombosis.  These authors note, contrary to ACCOAST, there was no detectable difference in bleeding between the pre-hospital and in-hospital groups.  They also note, as expected but not witnessed in ACCOAST, there was a reduction in short-term “definite” in-stent thrombosis.  Therefore, the authors – by which I mean AstraZeneca and their ghostwriters – clearly present this secondary outcome (Figure 2) and conclude pre-hospital ticagrelor is safe.

Interestingly, there was a 1% absolute difference favoring pre-hospital ticagrelor in “definite” in-stent thrombosis at 30 days – but a 0.2% absolute difference favoring in-hospital ticagrelor in “definite or probable” in-stent thrombosis.  For their definition, “probable” in-stent thrombosis included any death at 30 days for a patient receiving a stent.  I’m not sure the expanded definition accurately reflects underlying stent thrombosis, but it is a fair combined endpoint to report for completeness.

There are a few differences between this trial and ACCOAST, however.  In ACCOAST, patients were diagnosed with NSTEMI based on elevated troponin levels, and all were scheduled for coronary angiography 2 to 48 hours later.  In ATLANTIC, patients were diagnosed prehospital with STEMI – and required to undergo PCI within 120 minutes.  This reduced time of exposure to multiple anticoagulants may explain discrepancy in bleeding events between the trials.  The in-stent thrombosis rate was also much higher in the peri-PCI antiplatelet group in ATLANTIC compared with ACCOAST, leading to the possibility of detecting a difference in in-stent thrombosis.

Details aside, however – it’s simply not clear there’s any advantage to utilizing these agents outside the peri-PCI environment.  Regardless, I expect we will see more resources devoted to similar trials in slightly different populations, attempting to ferret out some subgroup and primary outcome definition capable of demonstrating a statistically significant benefit.

“Prehospital Ticagrelor in ST-Segment Elevation Myocardial Infarction”
http://www.nejm.org/doi/full/10.1056/NEJMoa1407024

The Most Dangerous Holiday!

Here in the United States, it is Labor Day – a Federal holiday established in 1886 by U.S. President Grover Cleveland.  We, apparently, have Canada to thank for this innovation.

But, what was actually news to me – Labor Day is actually the highest-volume holiday for pediatric trauma, outpacing all other holidays.  I’d have thought 4th of July – with it’s various explosive devices – would be the most popular pediatric trauma holiday, but, between 1997 and 2006, Labor Day takes the lead, followed by Memorial Day, and 4th of July as a close third.  Halloween, Easter, Thanksgiving, New Year’s and Christmas round out the list, in that order.

Most common documented products associated with injuries on Labor Day included:  Football, bicycles, stairs/ramps, playgrounds, and beds.  Contrast with Christmas:  Stairs, beds, skiing, tables, knives, and sofas.  And the article provides lists of appropriately seasonal injury mechanisms for each other holiday.

So – beware Labor Day!  The most dangerous holiday of the year!

“Epidemiology of Pediatric Holiday-Related Injuries Presenting to US Emergency Departments”
http://www.ncbi.nlm.nih.gov/pubmed/20368316