“Because It Doesn’t Just Happen to Other People”

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While doctors and scientists extol the virtues of vaccination to prevent disease, the emotional arguments regarding vaccines are sometimes lost due to misleading anecdotal stories.  The stories of missed opportunities and suffering due to the lack of vaccination are underreported.

Here’s an excerpt from one that wasn’t:  Link from Eric Benchimol: fw.to/IiBDiOH 

He, our oldest, 5 1/2, who the day before had been jumping merrily on the trampoline at circus school. Monday morning he woke up, out of breath, complaining of a tummy ache…..He came downstairs to watch TV, sank into the sofa, wheezing as if he had just run a marathon…

Everything was not okay. At noon, our big boy was in the pediatric intensive-care unit of the Centre hospitalier de l’Université Laval; he was plugged in everywhere, an oxygen mask covering his whole face, making him look like an astronaut. The respirator was whirring beside him, the oxygen desperately seeking its path, but not finding it…

The doctor said it was time to intubate, “to give him a chance…”

I marvelled at the work of the nurses, the doctors, in a constant death-defying dance. They put in long days and nights, 12 hours at a stretch and more. They obsessed, they never forgot, always determined to make the right decision at the right time.

Thursday morning, they decided to wake up our big boy, to remove the breathing tube, the IVs, trading them for a simple oxygen mask. Friday morning, the mask gave way to two little prongs in his nostrils. His battered lungs still needed some help. But his heart was beating normally again….

Each time I sat down in that blue leather chair, I wondered: “Where did that pneumonia come from? How did he get hit so hard, so fast?”…

The definitive diagnosis came Wednesday night: H1N1.

“Your son wasn’t vaccinated?”

We lowered our heads. Guilty as charged…

So why am I telling you all this? Why would I annoy you with this little story which, after all, happens to countless others every day during flu season?

Because it doesn’t just happen to other people.

Also, a link from the New England Journal of Medicine: nej.md/1hLXqWt 

An excerpt: “Influenza activity has been surging in the United States, and there are reports of critical illness and death in young and middle-aged adults. The predominant virus so far this season is influenza A(H1N1)pdm09, the cause of the 2009 H1N1 pandemic. Despite many challenges, there is much that the public, patients, the public health community, and clinicians can do now to reduce influenza’s impact…”

“Annual influenza vaccination is recommended for everyone 6 months of age or older in the United States..” It is not too late!

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Magnetic Resonance Elastography for Hepatic Fibrosis Assessment

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This large case series of 35 children indicates that Magnetic Resonance Elastography (MRE) may be quite useful to assess hepatic fibrosis as well as steatosis (J Pediatr 2014; 164: 186-8).

The study (2011-2012) included 27 patients with nonalcoholic fatty liver disease (NAFLD); 22 of this group had probable or definite nonalcoholic steatohepatitis (NASH).  Other diseases included progressive familial intrahepatic cholestasis (type 2), autoimmune sclerosing hepatitis, Wilson disease, glycogenic hepatopathy (due to type 1 diabetes), and other liver conditions.  All of the patients in the study had undergone liver biopsy as well.

The authors showed that MRE had a high accuracy to detect significant fibrosis and may be better suited for severely obese patients.  At the cutoff they identified, the sensitivity was 88% and the specificity 85% for detecting significant fibrosis.

In severely obese patients, alternative imaging techniques, namely transient elastography and acoustic radiation force imaging have higher technical failure rates.  The authors note that at their institution, more than 100 MRE studies have been completed (including many without liver biopsies); thus far, only two morbidly obese patients failed completion.  In addition, the authors state that this limited study costs about twice that of an ultrasound.

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Population-Based Outcomes for Primary Sclerosing Cholangitis

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A study from the Netherlands examined the outcomes for Primary Sclerosing Cholangitis (PSC) (Hepatology 2013; 2045-55). Using four independent hospital databases with 44 hospitals, allowed the investigators to identify 590 PSC patients from a population of almost 8 million. Median followup was 92 months. Mean age at diagnosis was 38.9 years.  A second comparison cohort of 450 patients was identified from three Dutch transplantation centers outside the study area.  134 (30%) of this cohort were present in the population-based cohort.  An IBD comparison group of 722 cases was identified as well from a population of 271,000 patients.

Results:

  • Prevalence: 6 per 100,000.  This is significantly lower than previous estimates.  The authors emphasize the problem with previous epidemiology studies and the need for population-based studies with rigorous case-finding.
  • Survival, estimated at 21.3 years for the entire cohort following diagnosis, was better than previous studies and this may indicate less selection bias than tertiary referral center studies.  It could also reflect diagnosis of milder cases with newer imaging techniques.
  • 402 (68%) of PSC patients were diagnosed with inflammatory bowel disease.
  • 23 (4%) had autoimmune hepatitis overlap.
  • Colorectal cancer was 10-fold increased compared to ulcerative colitis controls and developed at a younger age (39 years compared with 59 years).
  • Cholangiocarcinoma (CCA) was nearly 400-fold increased risk.  The cumulative risk of CCA was estimated at 20% after 30 years following PSC diagnosis.
  • During followup, there were 97 deaths; 73 (75%) were PSC-related.

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Liver Update: Headlines and Links Only

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  1. From AGA: Hepatic failure flagged as unexpected boceprevir safety signal in adverse event review. GI & Hep News: http://ow.ly/rSCEF 
  2. From NY Times: Spike in Harm to Liver Is Tied to Dietary Aids nyti.ms/JPN9fK 
  3. From Jeff Schwimmer (The Liver Post): First case report of Liver Cancer in a child with Nonalcoholic Fatty Liver Disease. He is only 7 years-old. http://goo.gl/6dJbzs 
  4. “Recurrence of Hepatopulmonary Syndrome Post-Orthotopic Liver Transplantation in a Patient with Noncirrhotic Portal Hypertension” Hepatology 2013; 58: 2205-06.
  5. “Management of Hepatitis B: Our Practice and How It Relates to the Guidelines” Clin Gastroenterol Hepatol 2014; 12: 16-26.  Terrific review and insights.
  6. “Acute Liver Failure” NEJM 2013; 369: 2525-34.
  7. “Cesarean Section Reduces Perinatal Transmission of Hepatitis B Virus Infection from Hepatitis B Surface Antigen-Positive Women to Their Infants” Clin Gastroenterol Hepatol 2013; 11: 1349-55. Retrospective, nonrandomized study -“performing elective cesarean section only in highly viremic mothers with pre-delivery HBV DNA levels ≥1,000,000 copies/mL may be advisable.”

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Consensus Guidelines on FMT

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Recent links from AGA for FMT (fecal microbiota transplantation) for Clostridium difficile –excellent resource:

Also, summary of recent abstracts from ACG regarding FMT for C difficile, IBS, and IBD: http://t.co/7LFnDYq5V5

Some previous blog posts on this topic:

How to Understand Scientific Studies

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From John Pohl’s Twitter Feed:

Twenty tips for interpreting scientific claims http://bit.ly/1hY3nD5. Referenced article: Nature 503, 335–337 (21 November 2013) doi:10.1038/503335a

An excerpt:

we suggest 20 concepts that should be part of the education of civil servants, politicians, policy advisers and journalists — and anyone else who may have to interact with science or scientists. Politicians with a healthy scepticism of scientific advocates might simply prefer to arm themselves with this critical set of knowledge…

Differences and chance cause variation…

No measurement is exact. Practically all measurements have some error…Results should be presented with a precision that is appropriate for the associated error, to avoid implying an unjustified degree of accuracy…

Bias is rife. Experimental design or measuring devices may produce atypical results in a given direction….

Bigger is usually better for sample size…

Correlation does not imply causation. It is tempting to assume that one pattern causes another. However, the correlation might be coincidental, or it might be a result of both patterns being caused by a third factor — a ‘confounding’ or ‘lurking’ variable…

Regression to the mean can mislead. Extreme patterns in data are likely to be, at least in part, anomalies attributable to chance or error…

Extrapolating beyond the data is risky. Patterns found within a given range do not necessarily apply outside that range…

Beware the base-rate fallacy. The ability of an imperfect test to identify a condition depends upon the likelihood of that condition occurring (the base rate). For example, a person might have a blood test that is ‘99% accurate’ for a rare disease and test positive, yet they might be unlikely to have the disease. If 10,001 people have the test, of whom just one has the disease, that person will almost certainly have a positive test, but so too will a further 100 people (1%) even though they do not have the disease.

Controls are important. A control group is dealt with in exactly the same way as the experimental group, except that the treatment is not applied. Without a control, it is difficult to determine whether a given treatment really had an effect…

Randomization avoids bias. Experiments should, wherever possible, allocate individuals or groups to interventions randomly…

Seek replication, not pseudoreplication. Results consistent across many studies, replicated on independent populations, are more likely to be solid…

Scientists are human. Scientists have a vested interest in promoting their work, often for status and further research funding, although sometimes for direct financial gain. This can lead to selective reporting of results and occasionally, exaggeration. Peer review is not infallible: journal editors might favour positive findings and newsworthiness. Multiple, independent sources of evidence and replication are much more convincing.

Significance is significant. Expressed as P, statistical significance is a measure of how likely a result is to occur by chance. Thus P = 0.01 means there is a 1-in-100 probability that what looks like an effect of the treatment could have occurred randomly, and in truth there was no effect at all. Typically, scientists report results as significant when the P-value of the test is less than 0.05 (1 in 20).

Separate no effect from non-significance. The lack of a statistically significant result (say a P-value > 0.05) does not mean that there was no underlying effect: it means that no effect was detected. A small study may not have the power to detect a real difference…

Effect size matters. Small responses are less likely to be detected…

Study relevance limits generalizations. The relevance of a study depends on how much the conditions under which it is done resemble the conditions of the issue under consideration…

Feelings influence risk perception. Broadly, risk can be thought of as the likelihood of an event occurring in some time frame, multiplied by the consequences should the event occur…

Dependencies change the risks. It is possible to calculate the consequences of individual events, such as an extreme tide, heavy rainfall and key workers being absent. However, if the events are interrelated, (for example a storm causes a high tide, or heavy rain prevents workers from accessing the site) then the probability of their co-occurrence is much higher than might be expected…

Data can be dredged or cherry picked. Evidence can be arranged to support one point of view…

Extreme measurements may mislead…

Comment: This is a really good reference to provide context for understanding scientific studies and sources of error.

Crisis or Not -Tough to Change Bad Habits

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For those of you with new resolutions, a sobering study from JAMA shows how difficult it is to change bad habits, even after a heart attack or a stroke.

From Sanjay Gupta’s twitter feed, link and excerpt: Video (1:48) http://ow.ly/sdS7R 

Even a brush with death is often not enough to get us to make better choices. Researchers studied more than 150,000 people from all around the world, rich and poor, urban and rural. Participants answered questions about exercise, diet, and smoking.

Because the group was so large, there were almost 8,000 participants who had survived either a heart attack or a stroke. The health habits of this group were startling. Only 39 percent reported improving their diet, and just 35 percent increased their physical activity. Of those who were smokers, only 52 percent quit. Just 4 percent of those 8,000 people improved their habits in all three areas: smoking, diet, and exercise.

Moving to All Oral Therapy for Hepatitis C

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Two more studies show the promise of all oral treatment for Hepatitis C virus:

  • NEJM 2014; 370: 211-21.
  • NEJM 2014; 370: 222-32.

A summary of these articles is available at the following link: http://t.co/Z8jMPKoLGz.

Here is an excerpt:

Hepatitis C treatment isn’t pretty, but the dark days of weekly injections, rough side effects and no guarantee of full recovery from the liver-damaging disease may soon be over, researchers report.

Two studies, both published in the Jan. 16 issue of the New England Journal of Medicine, involved giving various combinations of antiviral pill cocktails to patients with hepatitis C. Some had failed to respond to standard treatments, and some had not received treatment yet. Yet, the cocktails cleared the virus in both studies for between 93 percent and 98 percent of the patients…

The first study, conducted by Johns Hopkins researchers, included 211 men and women with hepatitis C who took two pill-form antiviral medications, daclatasvir and sofosbuvir. The patients were treated at 18 medical centers in the United States and Puerto Rico. They took 60 milligrams of daclatasvir and 400 milligrams of sofosbuvir for either 12 or 24 weeks, with or without a third drug, ribavirin….

98 percent of the 126 previously untreated patients and 98 percent of 41 patients whose infections had not cleared despite treatment with standard hepatitis C therapy, were considered cured. “There was no detectable virus in their blood three months after the treatment stopped,” he noted.

The second study, headed up by researchers at Virginia Mason Medical Center in Seattle, involved more than eight medical centers in the United States and internationally. It included 571 patients with hepatitis C, some of whom had not received treatment previously and others who had previously received standard treatments with interferon injections and ribavirin — an antiviral drug that when given reduces relapses — but had not responded to them.

The participants were randomly assigned to take any of three combinations of antiviral pills — medications called ABT-450, ABT-267, and ABT-333 — for eight, 12 or 24 weeks…

Almost all of the patients (more than 93 percent in both groups) saw the virus cleared from their systems within 24 weeks.

Bottomline: Once daily treatment with a combination of medicines will be an effective and safe cure for more than 90% of individuals with HCV. Whether these agents will be affordable remains in doubt.

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Science That Matters -Especially for Teenage Drivers

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Animated overview of distracted driving study narrated by Editor-in-Chief Jeffrey Drazen. http://nej.md/1hVzO1t (2:43 video from NEJM)

More explanation of this study from NY Times: http://nyti.ms/1dX4lcp 

“An inexperienced driver who reaches for a cellphone increases the risk for a crash by more than 700 percent, a new study found.”

Micronutrient Monitoring in Intestinal Failure

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J Pediatr 2013; 163: 1692-6.  This retrospective study of prospectively collected data from 178 children provides data with regard to micronutrient deficiency among intestinal failure patients transitioning to enteral feeds. Figures 1 and 2 along with Table 2 provide the prevalence of micronutrient deficiency while receiving supplemental parenteral nutrition (PN) and while on full enteral nutrition (FEN).  Iron deficiency was most common in both situations with prevalence of 84% and 61% respectively. With the exception of folate (0%), all of the vitamins and micronutrients had fairly high rates of deficiency.  While on FEN,  deficiencies were  the following:

  • Vitamin A        19%
  • Vitamin B12    6.5%
  • Vitamin D        30%
  • Vitamin E          6%
  • Copper            8%
  • Iron                61%
  • Selenium         4%
  • Zinc               23%

The study does not indicate that the deficiency values were adjusted based on CRP values.  Instead, “low serum levels were used to define deficiencies.”  This is likely to lead to numerous errors.  Nevertheless, it is clear that these deficiencies are common.  Another finding of the study was that normal anthropometrics did not reduce the frequency of these deficiencies.  In their patient population, 57 of 136 (42%) with sufficient height and weight data had a height-for-age z-scores of <-2 by the time of FEN; where as 52 of 139 patients (37%) had weight-for-age z-scores of <-2.

A recent post on The Pediatric Nutritionist blog provides a suggested approach to the monitoring of vitamins and micronutrients based on the need for parenteral nutrition and on the need to consider inflammatory markers in the interpretation of these lab values: The Importance of Nutrition Lab Monitoring Protocols Featuring …

Bottomline: Vitamin and micronutrient deficiencies are common among intestinal failure patients.  In addition, a large percentage of these kids are not large at all.

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What happens to micronutrient levels in the hospital setting …