Day: October 19, 2021

Doctors Should Avoid Reliance on Mental Shortcuts, Researchers Advise

Photo by Jafar Ahmed on Unsplash

The use of algorithms and analytics is widely used by professional sports, in sales forecasts, lending decisions and by car insurance providers. But doctors often remain reluctant to introduce such information when making medical decisions for patients. Often mental shortcuts, usually called decision rules or heuristics, are used.

Writing in an article published in Science, Helen Colby, an assistant professor of marketing at Indiana University, and Meng Li, associate professor of health and behavioural sciences at the University of Colorado Denver, note that it is time for many doctors to stop relying on their use of heuristics when making decisions about patient care with limited cognitive resources.

Profs Colby and Li wrote their accompanying editorial for an article in Science by Manasvini Singh, an assistant professor of health economics at the University of Massachusetts.

Using data for over 86 000 deliveries, Singh found that delivering physicians were influenced not just by the indications of the current patient but also by the outcome of their most recent previous delivery. For example, when a physician experienced a negative outcome with a vaginal delivery they were more likely to choose to deliver the next baby by caesarean section and vice versa.

“Most of the time, the heuristics do save time and resources and they produce pretty good outcomes. But in some situations, pretty good is not good enough,” Colby said. “When lives are on the line, any improvement in decision making can have life-saving consequences.”

Colby and Li highlight that a “win-stay-lose-shift” heuristic has been identified in other contexts as a learning strategy, but said it only works well in certain settings.

“In the medical context, this heuristic would be rational only if the specifics of the prior patient matched the specifics of the current patient and thus provided a useful learning experience. In that case, if one patient’s delivery went wrong, it can tell the physician that the same delivery plan may not work well with another patient with very similar characteristics and indications,” they wrote. “However, two patients who happen to have consecutive deliveries by the same physician are not expected to be highly similar.”

These mental shortcuts are not to suggest a lack of expertise or training, they stress, but the findings shows that it is a common tendency, even among more experienced doctors. Colby and Li offer several suggestions to help physicians overcome their reliance on maladaptive heuristics or decision rules. Firstly, the phenomenon needs to be acknowledged within the profession without condemning physicians.

“Although understanding decision biases usually does not entirely ameliorate them, teaching doctors about heuristics may promote the acceptance of potential interventions,” they wrote. “More research and clinical efforts need to focus on designing and testing decision aids that are beneficial to patients and user-friendly to physicians.

“In addition to making sure that the decision aid has a high degree of scientific accuracy in recommending the optimal treatment option, studies also need to examine whether physicians will accept and use such recommendations,” they added. “Physicians may have understandable concerns about recommendations from a ‘black box.’”

Prof Colby also said this is not an attempt to sound an alarm on doctors or castigate them for not always making optimal decisions, instead highlighting that doctors, like all experts, are only human.

“We patients, and often the doctors themselves, want to think of doctors and other healthcare staff as omniscient and omnipotent – a bastion of strength when we are in our time of need,” she said. “Doctors are regularly rated as the most respected profession in the United States, and a recent study found that doctors are often ascribed godlike powers.

“We cannot seek to assist medical decision making without first admitting the nature of the decision makers,” she added. “Helping doctors to make better decisions through reduced reliance on heuristics and decision rules should be a public health priority… It may be scary to admit that doctors are human, but it is the best thing we can do to help them, and ultimately to help them help us.”

Source: Indiana University

Upgrading the Diagnostic Power of Dipsticks

Source: Unsplash CC0

Popularly known as ‘dipsticks’, lateral flow assays (LFAs) have long been a standard point-of-care testing system, and continue to grow in popularity, especially in developing countries.

These disposable, paper-based diagnostic devices are inexpensive, readily available, have a long shelf life, and they’re fast, typically delivering results in under 20 minutes. They’re also easy to use at home, most commonly for pregnancy tests but also now for COVID.

“These tests have been extremely popular for years, mainly because they are so simple to use. You don’t send anything to the lab or clinic because these tests don’t require any external equipment to operate. This is an advantage,” said engineering researcher Fatih Sarioglu at the Georgia Institute of Technology. “But there also is a disadvantage. There are limitations to what they can do.”

Sarioglu and his team are overcoming the limitations of LFAs with development of a flow control technology, turning these simple tests into complex biomedical assays.

Their research is outlined in two papers in Science Advances and ACS Sensors. One explains the development of their technology and the other applies the technology in a toolkit to diagnose SARS-CoV-2, as well as influenza.

LFAs make use of capillary liquid flow to detect analytes. Sarioglu explained that conventional LFAs are not practical for performing multi-step assays – capillary flow precludes them from coordinating a complex process involving the application of multiple reagents in a specific sequence with specific delays in between.

The researchers describe a technique to control capillary flow by imprinting roadblocks on a laminated paper with water insoluble ink. The blocked liquid flow is thus manipulated into a void formed at the interface of the ink-infused paper and the polymer tape laminate. By modifying the roadblocks, the researchers can essentially set the time it takes for a void to form – creating timers that hold capillary flow for a desired period.

“By strategically imprinting these timers, we can program the assays to coordinate different capillary flows,” said Sarioglu, professor in the School of Electrical and Computer Engineering. “That enables multiple liquids to be introduced, and multistep chemical reactions, with optimal incubation times – so, we can perform complex, automated assays that otherwise would normally have to be performed in laboratories. This takes us beyond the conventional LFA.”

For the user, the new dipstick test works the same way as the reliable standard – a sample is added at one end and the results present themselves minutes later in living color(s) at the other end. Sarioglu and his colleagues simply enhanced and expanded the process in between.

Basically, they drew patterns on paper – a dipstick – and created immunoassays that rival other diagnostic tests requiring labs and extra equipment, in the effective detection of pathogenic targets like Zika virus, HIV, hepatitis B virus, or malaria, among others.

The paper in ACS Sensors describes a PCR-based point-of-care toolkit based on the lab’s flow technology. The assay is programmed to run a sequence of chemical reactions to detect SARS-CoV-2 and/or influenza A and influenza B. A traditionally labour-intensive genetic assay can now be done on a disposable platform which will enable frequent, on-demand self-testing, filling a critical need to track and contain outbreaks.

The lab is studying the technology’s application for other assays targeting other pathogens, with plans to publish in the coming months. Sarioglu is optimistic about the work’s potential.

“We believe this flow technology research will have widespread impact,” he said. “This kind of dipstick test is so commonly used by the public for biomedical testing, and now it can be translated into other applications that we do not traditionally consider to be cut out for these simple tests.”

Source: Georgia Institute of Technology

Protecting Newborns’ Brains During Rewarming Stage of Cooling Therapy

Photo by William-Fortunato on Pexels

Oxygen-deprived newborns who undergo hypothermia therapy have a higher risk of seizures and brain damage during the rewarming period, according to a new study. The finding, published online in JAMA Neurology, could lead to better ways to protect these vulnerable patients during an often overlooked yet critical period of hypothermia therapy.

“A wealth of evidence has shown that cooling babies who don’t receive enough oxygen during birth can improve their neurodevelopmental outcomes, but few studies have looked at events that occur as they are rewarmed to a normal body temperature,” said study leader Lina Chalak, MD, MSCS, Professor at UT Southwestern. “We’re showing that there’s a significantly elevated risk of seizures during the rewarming period, which typically go unnoticed and can cause long-term harm.”

Millions of newborns around the world are affected by neonatal hypoxic-ischaemic encephalopathy (HIE), brain damage initially caused by hypoxia during birth. Although the World Health Organization estimates that birth asphyxia is responsible for nearly a quarter of all neonatal deaths, those babies that survive oxygen deprivation are often left with neurological injuries, Dr Chalak explained.

To help improve outcomes, babies diagnosed with HIE are treated with hypothermia, using a cooling blanket that brings the body temperature down to as low as 33.5°C, said Dr. Chalak.

Studies initially showed that during cooling, babies with HIE commonly have symptomless seizures, which are neurological events that can further damage the brain, prompting the addition of electroencephalographic (EEG) monitoring to the hypothermia protocol. However, Dr Chalak explained, babies typically haven’t been monitored during the rewarming period, in which the temperature of the blanket is increased by 0.5°C every hour.

To better understand seizure risk during rewarming, Dr. Chalak and colleagues studied 120 babies who were enrolled in another study that compared two different cooling protocols, one longer and colder than the other. The babies in the study were also monitored with EEG to check for seizures both during the cooling and the rewarming phases of hypothermia.

When the researchers compared data from the last 12 hours of cooling and the first 12 hours of rewarming, they found that rewarming roughly tripled the odds of seizures. Additionally, babies who had seizures during rewarming, there was twice the risk of mortality or neurological disability by age 2, compared with those who didn’t have seizures during this period. This finding held true even after adjusting for differences in medical centers and the newborns’ HIE severity.

While it is not known how to prevent seizures from occurring in babies with HIE, treating seizures when they do occur can help prevent further brain damage, Dr Chalak said. Thus, monitoring during both cooling and rewarming can help protect the babies’ brains from further insults while they heal.

“This study is telling us that there’s an untapped opportunity to improve care for these babies during rewarming by making monitoring a standard part of the protocol,” said Dr Chalak.

Source: EurekAlert!

SARS-CoV-2 Can be Detected in Aircraft Wastewater

Photo by Lukas Souza on Unsplash

Australian researchers have found SARS-CoV-2 virus in wastewater samples from long haul flights arriving from outside the country, demonstrating that they can detect it even before passengers show symptoms.

The CSIRO and University of Queensland scientists worked with Qantas to show that wastewater surveillance can provide valuable data for public health agencies.

CSIRO lead author Dr Warish Ahmed said as global travel returns, testing wastewater of incoming flights could screen incoming passengers for COVID at points of entry.

“It provides an extra layer of data, if there is a possible lag in viral detection in deep nasal and throat samples and if passengers are yet to show symptoms,” Dr Ahmed said.

“The rapid on-site surveillance of wastewater at points of entry may be effective for detecting and monitoring other infectious agents that are circulating globally and provide alert to future pandemics.”

Co-author Professor Jochen Mueller from UQ’s Queensland Alliance for Environmental Health Sciences said wastewater testing could be a useful extra tool.

“The paper recommends that wastewater surveillance be used as part of an efficient clinical surveillance and quarantine system – providing multiple lines of evidence of the COVID infection status of passengers during international travel,” Professor Mueller said.

The study, published in Environment International, analysed wastewater samples from 37 Australian Government repatriation flights from COVID hotspots including India, France, UK, South Africa, Canada and Germany between December 2020 and March 2021.

The research found SARS-CoV-2 in wastewater samples from 24 of the 37 repatriation flights (65%) despite all passengers (except children under age five) having tested negative to the virus 48 hours before boarding. Virus is shed in the faeces of infected people about two to five days before showing symptoms.

Traces of SARS-CoV-2 can also be detected in wastewater from previously infected people who still shed the coronavirus, but are no longer infectious – although typically a weaker signal.

During 14 days of the passengers’ mandatory quarantine upon arrival in Australia, clinical tests identified only 112 COVID cases among the 6570 passengers (1.7%).

Monitoring of wastewater has a number of applications. Through its wastewater monitoring programme, the Durban University of Technology found that the recent unrest in South Africa was a superspreader event that drove up cases in KwaZulu-Natal.

Source: University of Queensland

Gut Microbes and Antibiotics Impact Inflammatory Pain

C difficile. Source: CDC

A study in rats showed that gut microbiomes and antibiotic use could modulate inflammatory pain.

Published in The Journal of Pain, the study examined the impact of antibiotics on the gut microbiome and how antibiotic use can alter inflammatory pain in subjects with or without access to exercise.

According to Glenn Stevenson, Ph.D., professor of psychology within the School of Social and Behavioral Sciences, this is the first publication to assess how antibiotic-induced changes to the gut microbiome impact inflammatory pain distal to the gut (in the limbs, for example).

The study determined the effects of vancomycin on inflammatory pain-stimulated and pain-depressed behaviours in rats, which was induced with formalin. Oral vancomycin administered in drinking water attenuated pain-stimulated behaviour, and prevented formalin pain-depressed wheel running. Faecal microbiota transplantation produced a non-significant trend toward reversal of vancomycin’s effect on pain-stimulated behaviour. Vancomycin depleted Firmicutes and Bacteroidetes gut populations while partially sparing Lactobacillus species and Clostridiales. The vancomycin treatment effect was associated with an altered profile in amino acid concentrations in the gut.

The results indicate that manipulation of the gut microbiome may be one method to attenuate inflammatory pain amplitude. Additionally, results indicated that the antibiotic-induced shift in gut amino acid concentrations may be a causal mechanism for this reduction in pain.

The research for this study took four years to complete, Prof Stevenson said, adding that the link between amino acids and pain reduction is “highly novel.”

Source: University of New England

Gauteng Vaccination Goals Under Threat

Image by Quicknews

Gauteng Premier David Makhura has stated that the province is not vaccinating enough people, which he acknowledged jeopardises its ambitious plans of having 70% of the population vaccinated by year end.

In a media briefing on Monday regarding the province’s vaccination rollout, he revealed that of Sunday, 5.3 million vaccines have been administered. More than 2.6 million people in Gauteng have been fully vaccinated. Gauteng’s infection rate has stabilised, with the number of active cases having fallen to approximately 1000. 

The Premier said that as things currently stand, there are still 4.4 million people in Gauteng that have to be vaccinated by the end of December. Makhura said that while they are still focussed on the target, it is becoming difficult to achieve, given the low numbers of people coming in for vaccinations.

“We are not retreating on our target of 70%, but the idea that we will meet 70% by mid-December is becoming a target that is elusive. The vaccination rate per day in Gauteng, on average during the week we are just between 52 and 58 000. We have fallen below the mid 60 000 daily vaccination rate. In September, we were doing extremely well. We were getting around 65-75 000.”

Based on last week’s total of 313 790 vaccinations, with 11 weeks in the year that would mean only about 3.5 million vaccinations administered – let alone persons fully vaccinated with a second dose. Concerns had been voiced at the end of September about flagging vaccination rates in South Africa as a whole.

Makhura also highlighted the low turnout of people in the province’s townships.

“Our townships are lagging behind. The substantial vaccinations are happening in more suburban areas, and the townships are lagging behind. Those townships in the south, Orange Farm and Palestine, we have the lowest number of vaccinations in the south of Johannesburg, that’s where we have 11% vaccination in terms of just single doses,” he said. 

Professor Bruce Mellado, of the Gauteng Provincial Command Council, said that, there was still a need to be cautious, especially with big events on the horizon, such as the municipal elections, saying:

“While the situation in the Gauteng Province remains stable and low risk, the risk of a fourth wave is very, very high. In fact, we predict that the fourth wave will hit sometime between November and January as we expect a number of super-spreader events to follow in a row. That’s something we have to have in mind.”

“We should not be confused or misled by the fact that we are currently in a situation of low risk, but that can change quite rapidly,” Prof Mellado cautioned.

Source: The South African

High-dose Heparin Reduces Mortality in Moderately-ill COVID Patients

SARS-CoV-2 viruses (yellow) infecting a human cell. Credit: NIH

A high dose of heparin, an inexpensive and globally available medication, reduces mortality risk in hospitalised, moderately-ill COVID patients, suggests a new study led by St. Michael’s Hospital.

Appearing in the BMJ, the RAPID Trial compared a high, therapeutic dose of heparin to a prophylactic low dose for patients with moderate COVID and elevated d-dimer levels admitted to hospitals. D-dimers are protein fragments produced when a blood clot gets dissolved; higher levels indicate increased clotting risks.

The researchers studied 465 patients in hospitals around the world and found that while the therapeutic dose of heparin was not associated with a significant reduction in the study’s primary outcome, a composite of death, the need for mechanical ventilation or admission to intensive care, the dosing of heparin did reduce all-cause death in moderately-ill COVID patients admitted to hospital by 78%.

“Our study confirms therapeutic heparin is beneficial in patients who are on the ward with COVID, but other studies suggest it could be harmful for patients who are in critical care,” said Dr. Peter Jüni, Director of the Applied Health Research Centre at St. Michael’s and co-lead of the study.

Therapeutic doses of heparin are used for deep vein thrombosis or pulmonary emboli, whereas prophylactic, or lower, doses are used for patients admitted to Internal Medicine wards to prevent blood clotting while they are in hospital.

Several trials have investigated using blood thinners in COVID patients due to heightened inflammation and clotting in blood vessels caused by the virus. Dr. Michelle Sholzberg, Head of the Division of Hematology-Oncology and Director of the Coagulation Lab at St. Michael’s, and co-lead on the study, hopes this research contributes to a change in treatment guidelines for COVID patients.

“This is a once-in-a-million opportunity – heparin is inexpensive, globally available, and exists in every single hospital pharmacy cabinet right now,” she said. “It’s an opportunity to rapidly repurpose a drug available around the world.”

In particular, she said, the treatment could make a difference in areas where vaccine availability or coverage continues to be limited. Heparin is included in the WHO’s list of essential medicines.

The researchers hope to learn more from the data collected by analysing it further to address new questions, and are also considering revisiting patient outcomes to understand whether these therapies reduce the odds of long COVID.

Source: Unity Health