New models may help predict diabetes progression

Posted December 2, 2016 by Jennifer Huber
Categories: Health

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Diabetics exposed to consistently high blood glucose levels can develop serious secondary complications, including heart disease, stroke, blindness, kidney failure and ulcers that require the amputation of toes, feet or legs.

In order to predict which diabetic patients have a high risk for these complications, physicians may use mathematical models. For example, the UKPDS Risk Engine calculates a diabetic patient’s risk of coronary heart disease and stroke — based on their age, sex, ethnicity, smoking status, time since diabetes diagnosis and other variables.

But this strategy doesn’t provide the accuracy needed by doctors. In response, a research team at Duke University has developed machine-learning computer algorithms to search for patterns and correlations in EHR data from approximately 17,000 diabetic patients in the Duke health system.

The group, led by Ricardo Henao, an assistant research professor in electrical and computer engineering, has demonstrated more accurate predictions than the UKPDS Risk Engine. A recent news story explains:

“This new model can project whether a patient will require amputation within a year with almost 90 percent accuracy, and can correctly predict the risks of coronary artery disease, heart failure and kidney disease in four out of five cases. The model looks at what was typed into a patient’s chart — diagnosis codes, medications, laboratory tests — and picks up on which pieces of information in the EHR are correlated with the development of a comorbidity in the following year.”

The Duke researchers plan to improve the model by training their machine-learning algorithms on a larger data set of diabetic patients from additional hospitals.

However, relying on EHR data has drawbacks. For instance, a patient’s EHR may be incomplete, particularly if the patient doesn’t consistently see the same doctors. Another major challenge is gaining access to the medical records for research. The Duke team had to contact all 17,000 patients to get their informed consent and may encounter similar challenges for a larger scale project.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

How does burnout affect NICU caregivers and their patients?

Posted December 1, 2016 by Jennifer Huber
Categories: Health

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Photo by U.S. Navy

We’ve all felt burned out at work due to prolonged stress — physically and emotionally exhausted, unmotivated, frustrated and maybe even cynical. But in the health-care field, burnout can harm patients as well as workers.

That concern prompted Stanford researchers to investigate the prevalence of caregiver burnout in neonatal intensive care units (NICUs) to determine whether it is correlated with healthcare-associated infections. The study is reported in the Journal of Perinatology.

The research team analyzed survey data from the California Perinatal Quality Care Collaborative, including responses from over 2000 providers — physicians, nurses and other workers — in 44 California NICUs who cared for over 4000 very low birth rate infants. One quarter of the respondents reported symptoms consistent with burnout on average, but burnout prevalence varied from 7.5 to 54.4 percent within each NICU.

I spoke recently with the study’s lead author, Daniel Tawfik, MD, a critical care fellow at Lucile Packard Children’s Hospital.

What inspired you to investigate caregiver burnout in NICUs?

“Throughout my medical training, I received very little education on the concepts of mindfulness and medical provider well being. But the challenging experiences and stressful situations encountered every day in the hospital must have some impact on the providers’ mental health and the care they deliver to their patients. This study was a way to evaluate this relationship and hopefully spur greater awareness of burnout and encourage research to address its role in patient care.”

What did you find? Were there any surprises?

“We expected to find increased healthcare-associated infections in NICUs with high levels of burnout, since preventing infections in these vulnerable patients takes a great deal of vigilance.

We were a little surprised that there wasn’t a strong relationship apparent when we analyzed the data. This may be due to the relatively small number of NICUs and the fact that infections were fortunately not very common in this group of infants.

Although our most recent analyses show increased burnout among large NICUs, our research group previously reported improved outcomes among large NICUs. It’s possible that the largest NICUs have increased burnout, but they also have systems in place to improve the quality of care — counteracting the effect that burnout may have on quality indicators.

We were also a little surprised to find that physician burnout [approximately 17 percent] was less prevalent than non-physician burnout [approximately 28 percent]. But this discrepancy is also in line with our previous studies in which nurses reported lower ratings of safety culture and a desire for more respect and input in decision-making. It’s possible that these differences contributed to increased burnout among nurses, who made up the majority of our survey respondents in our new study.”

How can your results be used to improve NICU care?

“These results highlight the prevalence of burnout among NICU providers, particularly among nurses. Whether or not this burnout affects quality of care in measurable ways, it suggests that we need interventions to prevent and reduce burnout in NICUs and likely in other care settings.

The NICU at Lucile Packard Children’s Hospital is one of several NICUs around the country participating in the WISER randomized-controlled trial, which is evaluating the effectiveness of burnout interventions such as daily recall of positive events using the Three Good Things tool. The study is being led by Jochen Profit, MD, and Bryan Sexton, PhD, who have been my mentors and co-authors. It’s our hope that if this intervention proves beneficial that it could be expanded to other hospital units and clinics.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Saliva tests may help identify marijuana-impaired drivers

Posted November 22, 2016 by Jennifer Huber
Categories: Health, Technology

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Photo by ashton

Photo by ashton

As of the recent election, seven states and the District of Columbia have now legalized marijuana for recreational use and 19 other states have legalized medical marijuana. And this legalization has raised concerns about driving under the influence of marijuana.

A number of research groups are now focusing on ways to identify drivers impaired by marijuana. As recently reported by KQED, the Center of Medicinal Cannabis Research at the University of California, San Diego, are working to “gather data about dosages, time and what it takes to impair driving ability — and then create a viable roadside sobriety test for cannabis.” And a group of Stanford engineers have created a test called a ‘potalyzer.’

The Stanford effort was led by Shan Wang, PhD, a Stanford professor of materials science and engineering and of electrical engineering. He and his colleagues developed a mobile device that detects the amount of tetrahydrocannabinol (THC) molecules in saliva. (THC is the main psychoactive agent in marijuana.)

The test would allow police officers to collect a saliva sample from the driver’s mouth with a cotton swab, analyze it with the new device, and then read the results on a smartphone or laptop in as little as three minutes.

The technology combines magnetic nanotechnology with a competitive immunoassay. During the test, saliva is mixed with antibodies that bind to both THC molecules and magnetic nanoparticles. The mixture is placed on a disposable test chip, inserted into the handheld device and the THC-antibody-nanoparticles are detected by magnetic biosensors. The biosensor signal is then displayed on a Bluetooth-enabled device.

Wang’s group focused on developing a THC saliva test because it is less invasive and may correlate better with impairment than THC urine or blood tests. Also key is the need for a very sensitive test. A Stanford news release explains:

“Wang’s device can detect concentrations of THC in the range of 0 to 50 nanograms per milliliter of saliva. While there’s no consensus on how much THC in a driver’s system is too much, previous studies have suggested a cutoff between 2 and 25 ng/ml, well within the capability of Wang’s device.”

There is still a lot to do before police can deploy this ‘potalyzer’ device, including making it more user-friendly, getting it approved by regulators and investigating whether there is a better biomarker to detect marijuana impairment than THC. In addition, the test may not work well for THC edibles, the researchers wrote in a recent paper published in Analytical Chemistry.

On the upside, the Stanford technology could also be used to test for morphine, heroin, cocaine or other drugs — and for multiple drugs at the same time.

More research is needed, but there is now a new funding source in California: Proposition 64 allots millions of dollars per year to research marijuana and develop ways to identify impaired drivers.

This is an expanded version of my Scope blog story, courtesy of Stanford School of Medicine.

Dr. B’s brain collection helps local students learn anatomy

Posted November 21, 2016 by Jennifer Huber
Categories: Science Education

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Photo courtesy of Donna Bouley

Most of the time, veterinary pathologist Donna Bouley, DVM, PhD, provides pathology support for Stanford researchers and clinicians who work with animals.

But she also has an unusual hobby: Bouley, known to all as Dr. B, collects animal brains. Since 1997, she and others have taken “Dr. B’s Brain Collection” to local schools for a variety of science programs. Fascinated by this idea, I contacted her to learn more.

What inspired you to create your brain collection? What does it include?

“When I first started as faculty at Stanford, there were some preserved brains in the necropsy [animal autopsy] lab. I decided to start collecting more brains from animals that came to necropsy, when we didn’t need their brains to make our diagnosis. The word somehow got out that such a resource existed on campus. Now, I actually have two collections that are almost identical, because multiple labs were interested in borrowing the collection at the same time.

In each collection, I try to have at least one of the following brains: sheep, pig, dog, macaque, squirrel monkey, rabbit, owl, rat, mouse, cyclid (fish), and Xenopus laevis (an African Clawed frog). The brains are preserved and sealed in ‘seal-a-meal’ style bags or jars.

If any new species come through necropsy, I try to get brains from those animals. I also have to replace damaged ones each year, since the enthusiasm of middle schoolers can often result in the rough handling of my bagged brains. My necropsy tech keeps a close watch over the condition of the collections and replaces brains as needed or when available.”

How do you use the collection at Stanford?

“I teach a freshman seminar called Comparative Anatomy and Physiology of Mammals that tends to have several pre-vet and pre-med students each year. I use these brains to demonstrate various features that are similar or different between them, such as overall size, location of the cerebellum or the extent of brain surface folds and ridges. For instance, in lower mammals such as rodents — that survive mainly on instinct rather than cognitive processing — the brain has a very smooth surface. In mammals such as a pig, dog, or macaque that are higher functioning and quite intelligent, the brain surface is highly folded or convoluted. And dolphins and elephants have even more convolutions in their brains than humans!

I also have colleagues that teach Comparative Neuroanatomy at the graduate level and they borrow the brains.

I can only speak about my own college student reactions to exposure to this field and tell you in general they are amazed and in awe. They never look at animals the same after taking my class.”

How do others use the brain collection?

“Graduate students from Stanford psychology or neurobiology labs generally take a brain collection to nearby middle schools, where they work with students during a science class. They most likely also bring some human brains that they compare to the animal brains. Having unique visual teaching tools — real brains, not models or pictures — helps the middle schoolers gain insight into the complexity of the nervous system. Learning about anatomy from a truly comparative aspect is incredibly valuable, because it demonstrates the similarities as well as the unique differences between humans and other mammals.

I’m sure that ‘Dr. B’s Brains’ provide a very lasting impression on students.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Many adults should now take statins, task force recommends

Posted November 15, 2016 by Jennifer Huber
Categories: Health

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Illustration by Rf Vectorscom

Illustration by Rf Vectorscom

The U.S. Preventative Services Task Force now recommends that many adults take a low to moderate dose of statin to reduce their risk of a heart attack or stroke, even if they don’t have a history of cardiovascular disease.

Statins are drugs that reduce the production of cholesterol by the liver — lowering bad cholesterol and triglycerides and raising good cholesterol. The task force comprehensively reviewed the literature on clinical trials and observational studies involving statin use. It concluded that the benefits of using statins outweighed the harms in some patients with increased risk of cardiovascular disease.

Douglas Owen, MD, a Stanford professor of medicine and director of the Center for Health Policy, was a member of the task force when the guidelines were developed. He summarizes the new recommendations in a recent news story:

“The task force recommends that clinicians offer statins to adults who are 40 to 75 years old and have at least one existing cardiovascular disease risk, such as diabetes, hypertension, high cholesterol or smoking. They also must have a calculated risk of 10 percent or more that they will experience a heart attack or stroke in the next decade. The task force recommends that clinicians use the American College of Cardiology/American Heart Association risk calculator to estimate cardiovascular risk because it provides gender- and race-specific estimates of heart disease and stroke.”

The task force hope these new recommendations will help clinicians better identify cardiovascular risk, so their patients can take steps to reduce their risk, such as eating a healthy diet, exercising and potentially taking a statin.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Brain scans detect lies better than polygraph tests, new study shows

Posted November 11, 2016 by Jennifer Huber
Categories: Health

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Forget fact checkers or polygraph tests. A functional magnetic resonance imaging (fMRI) brain scan might be the best way to tell if someone is lying.

According to a study from the University of Pennsylvania, our brains are more likely to give us away when we’re lying than sweaty palms, rapid breathing or spikes in blood pressure, the factors tracked by polygraph tests.

The researchers directly compared the ability of two techniques — fMRI and polygraph tests — to detect concealed information. They had 28 participants secretly write down a number between 3 and 8 on a slip of paper. Each participant then had both lie-detection tests, in random order, a few hours apart. During both sessions, they always answered “no” when asked if they had picked a certain number, which meant that one out of the six answers was a lie.

Three fMRI experts and three professional polygraph examiners then independently analyzed the results. The fMRI experts were 24 percent more likely to detect the lie than the polygraph experts, as recently reported in the Journal of Clinical Psychiatry.

Although the study wasn’t designed to evaluate the combined use of both techniques, the polygraph and fMRI results agreed correctly on the concealed number for 17 participants. So they plan to investigate in the future whether these techniques are complementary.

The study includes only a small number of participants, but the research team is encouraged by the results. “While the jury remains out on whether fMRI will ever become a forensic tool, these data certainly justify further investigation of its potential,” said Daniel Langleben, MD, first author and a professor in psychiatry, in a recent news release.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Talk about death — before a health crises, says Stanford’s Philip Pizzo

Posted November 10, 2016 by Jennifer Huber
Categories: Health

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Photo by Oldiefan

Most of us have no desire to think, or talk, about death. However, if we never talk about it, we leave our health providers and families guessing about how and where we want to die.

That’s why it’s important to communicate end-of-life preferences early, Philip Pizzo, MD, founder and director of the Stanford Distinguished Careers Institute, argues in a recent perspective in the Proceedings of the National Academy of Sciences.

It’s a topic he’s quite familiar with: Pizzo co-authored the Institute of Medicine’s report “Dying in America,” which addressed how to improve the quality of care for patients with advanced illnesses, without exacerbating the high costs of health care. In the perspective, he summarizes the IOM report’s key recommendations and provides an update.

Pizzo discussed the piece in an email:

“Unless we are facing an illness or event that makes the prospect of death imminent, most of us do not even think about the inevitability of our mortality. These conversations get slotted to times when death is more imminent and when our crisis-oriented decisions may not reflect our true preferences. That is why the IOM report recommended that conversations about death take place with our health care providers and families throughout life. Our thoughts and preferences about dying will vary at different stages of life and wellbeing.”

In the perspective, Pizzo describes the progress that has been made since the report was published. For instance, the Centers for Medicare & Medicaid Services in January 2016 began paying doctors to have end-of-life conversations with patients — a move Pizzo lauds as a major step.

Another important achievement, according to Pizzo, is the national stakeholder conferences that are now bringing constituencies together to implement the report’s recommendations.

He added:

“We witnessed before the IOM Committee began its work how rapidly public opinion can be swayed by political rhetoric. Thankfully since then, the public’s willingness to engage in conversations about death and dying have become better realized and books, like Atul Gawande’s Being Mortal or Paul Kalaniti’s When Breath Becomes Air, have helped to foster more enlightened conversations about dying.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

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