Causes of extreme weather and climate events in China during 2020/21

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

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IMAGE: FIGURE 1. SCHEMATIC DIAGRAMS OF ATMOSPHERIC CIRCULATION PATTERNS ASSOCIATED WITH THE WINTER COLD SURGES. (A) A NORMAL, MILD WINTER WITH THE RELATIVELY FLAT JET STREAM. (B) A COLD SURGE IN... view more 

CREDIT: CHUNZAI WANG

During the summer of 2020, especially June and July, periods of extreme heavy rainfall occurred in China's Yangtze River Valley (YRV). These rain events caused the severest floods for the region since the summer of 1998. Despite this, the 2020 western North Pacific (WNP) typhoon season started slowly, but eventually produced 23 named tropical cyclones, still slightly below 27, the WNP seasonal average. As summer transitioned to winter, three severe cold surges swept most parts of China during late 2020 and early 2021, prompting the National Meteorological Center to issue its highest cold surge warning alert for the first time in four years. After a volatile weather year, scientists are finding answers as to why the past year featured so many extreme weather and climate events in China.

Professor Chunzai Wang and his team in the State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences were tasked to analyze global and regional climate influences that may have played roles in the 2020/21 extreme weather events. The researchers found many key oceanographic and meteorological connections, which have just been published in Advances in Atmospheric Sciences.

Sea surface temperature (SST) fluctuations in the tropical Pacific, Indian, and Atlantic Oceans can contribute to heavy rainfall events in China. However, observational data suggest that Atlantic and Indian Ocean influences dominate over those from the Pacific. Beginning in May 2020, positive SST anomalies, or change from average, throughout the tropical western North Atlantic (WNA) induced positive geopotential height anomalies in June over the mid-latitude North Atlantic. Geopotential height is the altitude above sea level at which a certain pressure surface exists, typically analyzed at 500mb. This metric is excellent for identifying the ridges and troughs which affect the rainfall anomalies in the YRV via an Atlantic-induced atmospheric "wave train" across Eurasia. Further analysis suggests that the Indian Ocean did not significantly affect June rainfall over the YRV. However, when considering June and July rainfall together, both the Indian Ocean and WNA influences are important.

Regarding the extremely cold surges during the 2020/21 winter, Prof. Wang's team points to the Siberian High. An enhancement and northward movement of the Siberian High force the jet stream to develop a wavy pattern. This disrupts the polar vortex, allowing cold polar air to invade southward, thus inducing the cold surges in China (Fig. 1b) and North America (Fig. 1c).

The below average 2020 typhoon season is associated with large vertical wind shear (which is defined as the wind difference between the upper and lower troposphere) and low humidity in the WNP. Tropical cyclones do not form and develop in heavily sheared and dry environments. Scientists believe that these are responsible for fewer typhoons in the first half of the 2020 typhoon season.

This study points out the importance of three-ocean interactions and their influences across the Northern Hemisphere. The tropical Pacific, Indian, and Atlantic Oceans can affect the anticyclone in the WNP, providing moisture transport to its northwest side, therefore increasing summer rainfall in China. The same anticyclone also modifies atmospheric circulation and thermodynamic factors in the WNP, influencing typhoon activity. Global warming can increase the occurrence of extreme weather and climate events. However, future studies are needed to quantify the influences of global warming on an individual extreme weather and climate event.

Matheson was well known for his poetic, almost Shakespearean language on air. He widely referred to "that most dreaded of all meteorological phenomena, the Siberian High" or its counterpart, the "Keep your eye on the Idaho High".

Professions: Weather presenter

Died: September 19, 2006

Born: April 26, 1926, Lethbridge

Bill Matheson - Wikipedia

Observations indicate strengthening of tropical Pacific western boundary currents for six decades

SCIENCE CHINA PRESS

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IMAGE: GEOSTROPHIC CURRENTS RETRIEVED FROM MULTI-DECADAL HYDROLOGICAL OBSERVATIONAL DATA BASED ON WOA18 ((A), (B), (D), (E), CM S?1) AND THE MEAN HORIZONTAL ABSOLUTE VELOCITY |U| IN THE UPPER 200 M SIMULATED... view more 

CREDIT: ©SCIENCE CHINA PRESS

Under the background of global warming, the energy budget of the earth is out of balance with more than 90% of additional heat entering the ocean.

The tropical Pacific Ocean has an important influence on the global tropical climate and the climate of China, and the tropical Pacific Western Boundary Currents (WBCs) that flow through it plays an important role in the climate system. Large-scale ocean circulation redistributes ocean heat and mass and is hence one of the basic dynamic processes that shape the earth's Marine environment. The tropical Pacific WBCs system is a key part of the global ocean circulation system. Accurate assessment of the variation of the tropical Pacific WBCs is of much significance for better understanding of the variability of the Earth's climate system.

Recent study has shown that under the background of global warming, the global mean ocean circulation has significantly accelerated over the past 20 years, and this acceleration process is mainly in the global tropical waters. However, it is not clear whether the tropical Pacific WBCs will strengthen or weaken in the context of global warming, and the key to answering this question lies in ocean observations.

Recently, an article titled "Multi-decadal trends in the tropical Pacific western boundary currents retrieved from historical hydrological observations" was published in the Science China Earth Sciences. The research team led by Professor Shijian Hu, who is the first author from Institute of Oceanology, Chinese Academy of Sciences, evaluate the multi-decadal trends in the tropical Pacific WBCs using historical hydrological observations collected in the past over 60 years.

Hu's team focused on the tropical Pacific region and calculated the geostrophic components of the North Equatorial Current (NEC), North Equatorial Countercurrent (NECC), Mindanao Current (MC), Kuroshio in the origin and the New Guinea Coastal Undercurrent (NGCUC) using decadal mean hydrological observations from the World Ocean Atlas 2018 (WOA18), which is available from 1955 to 2017. Volume transports of the WBCs and their multi-decadal trends are estimated, and contributions of temperature change and salinity change to the trends are discussed. It is found that the NEC, MC and NGCUC show a significant strengthening trend in the past six decades, mainly due to the contribution of temperature change, and the trend pattern of dynamic height is consistent with the WBCs trend. Zonal wind stress averaged over the WBCs' latitudes of the western tropical Pacific is found to accurately reproduce the decadal variability and multi-decade strengthening trend of the WBCs. The authors suggested that the observed intensification of WBCs is attributed to a strengthening of trade winds in the western Pacific Ocean. This study provides important observational evidence for estimating the multi-decadal trend of large-scale ocean circulation in the western Pacific under a rapid climate warming.

CAPTION

The volume transports ((a)-(e), unit: Sv) of the WBCs in the tropical Pacific and the linear trends (f). The red and blue lines represent the transport variations contributed by the temperature and salinity variations, respectively. The percentage of a total trend related to each mean volume transport over the six decades for each current is shown in panel (f) ("+" indicates increase). Positive values in zonal currents (NEC, NECC, NGCUC) represent transports to the east while positive values in meridional currents (KC, MC) represent transports to the north. The red, blue, and black lines represent the trends over the periods of 1955-2017, 1965-2017, and 1965-2004 while the solid dot line represents the uncertainty defined as the standard deviation of trend-removed time series.

CREDIT

©Science China Press

This research was funded by the National Natural Science Foundation of China, the Strategic Priority Research Program of Chinese Academy of Sciences (CAS), and the CAS-CSIRO Project Fund. Shijian HU is a member of the Youth Innovation Promotion Association of CAS.

See the article: Hu S, Lu X, Li S, Wang F, Guan C, Hu D, Xin L, Ma J. 2021. Multi-decadal trends in the tropical Pacific western boundary currents retrieved from historical hydrological observations. Science China Earth Sciences, 64(4): 600-610, https://doi.org/10.1007/s11430-020-9703-4

https://www.sciengine.com/publisher/scp/journal/SCES/64/4/10.1007/s11430-020-9703-4?slug=fulltext

https://link.springer.com/article/10.1007/s11430-020-9703-4

KICT's solution for monitoring massive infrastructures

A trailblazer for developing a new paradigm for structural monitoring

NATIONAL RESEARCH COUNCIL OF SCIENCE & TECHNOLOGY

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IMAGE: COMPLEMENTARY DATA-FUSION FRAMEWORK USING MULTI-FIDELITY DATA view more 

CREDIT: KOREA INSTITUTE OF CIVIL ENGINEERING AND BUILDING TECHNOLOGY (KICT)

The Korea Institute of Civil Engineering and Building Technology (KICT) has announced the development of an effective structural monitoring technique to monitor massive infrastructures, such as long-span bridge. The method provides accurate and precise responses over whole structural system densely by fusing advantages of multi-fidelity data.

Rapid advances in sensing and information technologies have led to condition-based monitoring in civil and mechanical structural systems. The structural monitoring system plays a key role in condition-based monitoring to evaluate structural safety from responses measured by sensors. In other words, following method allows to examine the health of an existing structures, such as a long-span bridge. The structural monitoring system can enable early detection for an unsafe condition and enable proactive maintenance. As a result, it greatly reduces the inspection burden as well as maintenance costs. The prerequisite for the successful condition-based monitoring is to obtain accurate responses through the whole structural system. Especially in civil-infrastructures, high cost, and technical difficulty are some challenging issues.

In order to solve this problem, a research team in KICT, led by Dr. Seung-Seop Jin, has developed an effective as well as efficient data-fusion method for condition-based monitoring. With the following method, the complementary data-fusion for the point and distributed strain sensor is performed to combine their advantages in order to obtain the accurate strain distribution over whole infrastructures; thereby, responses can be estimated with high accuracy densely over whole infrastructures.

For structural response, the multi-fidelity data consists of point and distributed sensors, which have different fidelities. The point sensor provides high accurate and reproducible responses at discrete measurement positions (High-fidelity data, HF-data), while a distributed sensor utilizes the scattering-based or scanning sensing technique to obtain very dense responses using the quasi-continuous sensing (Low-fidelity data, LF-data). The LF data is relatively easy to acquire, so it is possible to produce large amounts of relatively inaccurate data for response trend over whole infrastructure. On the contrary, the HF data provides high accuracy; however, it is limited to acquire in terms of both time and technical limitations. Therefore, the limited amount of data is available and this can significantly impair the ability to diagnose structural conditions over whole infrastructures. Although they can be complemented each other, their complementary data-fusion has not been studied yet for the structural monitoring system. KICT firstly recognizes their potentials and developed the complementary data-fusion framework by exploiting a multi-fidelity modeling in Computational statistics and Geo-statistics. The basic concept of the developed method is to transfer knowledge of the abundant but potentially inaccurate LF-data (response trend) to enhance their accuracies by fusing the information from the HF-data (accuracy at some points).

The newly developed method was verified by a number of the numerical tests with other existing multi-fidelity data-fusion methods. In order to consider possible situations in real applications, the developed method was extensively evaluated through Monte Carlo simulations by varying the number and locations of multi-fidelity data with the noise. The results show that the prediction performance of the developed method is consistently superior to other existing methods. In both experiments, the relative percentages of accuracy (maximum absolute error) are improved up to 171.3% and 192 % to the existing methods.

The method is very versatile for structural monitoring, especially for massive infrastructures. The developed method is currently improved to make it more robust and efficient. For better generalized capability, the developed method requires flexible learning capability for extracting the information from both the HF-data and LF-data and fusing them. Such improvements include the following.

Dr. Jin said, "The rationale behind this improvement is similar to our decision-making in real life. We seek different options and combine them to make the best decision. Similar to our decision-making, we do not have high confidence on the unknown damages. In the current method, we have to utilize specific models and some parameters in these models. It should be noted that a best model and its parameters are case-dependent. Therefore, we pursue several options for flexible modeling. To deal with various conditions in infrastructures, we can adopt a flexible and self-learning framework such as optimal kernel learning for better data-fusion. This idea takes a step towards autonomous and efficient monitoring system for massive infrastructures."

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The Korea Institute of Civil Engineering and Building Technology (KICT) is a government sponsored research institute established to contribute to the development of Korea's construction industry and national economic growth by developing source and practical technology in the fields of construction and national land management.

This research project is funded by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT). (No. 2020R1C1C1009236). An article explaining the results of this research was published in Volume 157 of Mechanical Systems and Signal Processing, a renowned international journal in the ENGINEERING, MECHANICAL category (IF: 6.471, top 3.846% of JCR).

- Journal Paper

Jin et al. (2021), Combining point and distributed strain sensor for complementary data-fusion: A multi-fidelity approach, Mechanical Systems and Signal Processing, Vol. 157, 107725; https://doi.org/10.1016/j.ymssp.2021.107725

CAPTION

Basic concept of the developed method is to enhance the response trend from distributed sensor by fusing the accuracy from a few point sensors.

CREDIT

Korea Institute of Civil Engineering and Building Technology (KICT)

CAPTION

Experimental validation were performed with other methods (MFHKRG and MFKO). As a result, the developed method (MFGP-mapping(SE)) shows much lower maximum absolute error (MAE) than other method. More details can be found in the Journal paper in Mechanical Systems and Signal Processing (https://doi.org/10.1016/j.ymssp.2021.107725)

CREDIT

Korea Institute of Civil Engineering and Building Technology (KICT)

Social media and science show how ship's plastic cargo dispersed from Florida to Norway

UNIVERSITY OF PLYMOUTH

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IMAGE: AN INK CARTRIDGE WASHED UP ON A BEACH IN CORNWALL AND RECOVERED BY THE LOST AT SEA PROJECT view more 

CREDIT: TRACEY WILLIAMS, LOST AT SEA PROJECT

A ship's container lost overboard in the North Atlantic has resulted in printer cartridges washing up everywhere from the coast of Florida to northern Norway, a new study has shown.

It has also resulted in the items weathering to form microplastics that are contaminated with a range of metals such as titanium, iron and copper.

The spillage is thought to have happened around 1,500 km east of New York, in January 2014, with the first beached cartridges reported along the coastline of the Azores in September the same year.

Since then, around 1,500 more have been reported on social media, with the greatest quantities along the coastlines of the UK and Ireland but also as far south as Cape Verde and north to the edge of the Arctic Circle.

The study was conducted by the University of Plymouth and the Lost at Sea Project, who have previously worked together on research suggesting LEGO bricks could survive in the ocean for up to 1,300 years.

For this new research, they combined sightings data reported by members of the public and oceanographic modelling tools to show how the cartridges reached their resting place.

Some were carried by the Azores and Canary currents around the North Atlantic Gyre, while others were transported northwards with the North Atlantic and Norwegian currents.

Writing in the journal Environmental Pollution, the researchers say the dates of first sightings suggested the cartridges travelled on average between 6 cm and 13 cm per second, demonstrating how quickly buoyant items can be dispersed across the oceans.

Through microscopic and X-ray fluorescence analyses, they also revealed a high degree of exterior weathering that resulted in the cartridge surfaces becoming chalky and brittle.

This has resulted in the formation of microplastics rich in titanium, the chemical fouling of interior ink foams by iron oxides, and, in some cases, the presence of an electronic chip containing copper, gold and brominated compounds.

Significantly, the study's authors say, the latter characteristic renders cartridges as electrical and electronic waste and means the finds are not governed by current, conventional regulations on plastic cargo lost at sea.

Lead author Dr Andrew Turner, Associate Professor (Reader) in Environmental Sciences at the University of Plymouth, said: "Cargo spillages are not common, but estimates suggest there could be several thousand containers lost at sea every year. They can cause harm to the seabed but, once ruptured, their contents can have an impact both where they are lost and - as shown in this study - much more widely. This research has also shown once again how plastics not designed to be exposed to nature can break down and become a source of microplastics in the environment. It also calls into question the relevance and robustness of current instruments and conventions that deal with plastic waste and its accidental loss at sea."

Tracey Williams, founder of the Cornwall-based Lost at Sea Project, added: "This study also highlights the potential usefulness of social media-led citizen science to marine research. Over many years, members of the public have helped us to show the amount of plastic in our seas and on our beaches. It is something people care passionately about and are committed to trying to solve."

CAPTION

A selection of the printer cartridges found along the coastlines of the North Atlantic and then analysed in laboratories at the University of Plymouth

CREDIT

Andrew Turner, University of Plymouth

Team builds better tool for assessing infant brain health

UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU

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IMAGE: BECKMAN INSTITUTE RESEARCHER RYAN LARSEN AND HIS COLLEAGUES HAVE DEVELOPED A NEW METHOD FOR ASSESSING METABOLITE LEVELS IN THE INFANT BRAIN. THEIR OPEN-ACCESS TOOL WILL HELP DOCTORS AND RESEARCHERS COMPARE... view more 

CREDIT: PHOTO BY FRED ZWICKY

CHAMPAIGN, Ill. -- Researchers have created a new, open-access tool that allows doctors and scientists to evaluate infant brain health by assessing the concentration of various chemical markers, called metabolites, in the brain. The tool compiled data from 140 infants to determine normal ranges for these metabolites.

Published in the journal NMR in Biomedicine, the study describes an easier and more reliable way to evaluate metabolite concentrations in the infant brain than was previously available, said study lead Ryan Larsen, a researcher at the Beckman Institute for Advanced Science and Technology at the University of Illinois Urbana-Champaign.

Metabolites play an important role in normal brain growth, development and function, said study co-author Dr. Ellen Grant, the director of the Fetal Neo-Natal Neuroimaging and Developmental Science Center at Boston Children's Hospital and a professor of radiology and of pediatrics at Harvard Medical School. High or low metabolite levels in the brain may be the first sign of problems with brain function or development.

"For example, we look at choline, which plays a role in building myelin, the sheath that allows electrical impulses to travel along neurons," Grant said. "Another metabolite, called NAA, is important to the healthy growth and proliferation of dendrites, the branches on neurons that receive signals from other neurons."

By measuring the concentration of key metabolites like these, researchers can spot some problems early - allowing interventions in time to prevent damage to the growing brain, she said.

Assessing metabolites in the brain normally involves proton magnetic resonance spectroscopy, a technology that uses an MRI not for visual imaging but to detect and identify specific molecules in the tissues of interest. The most common approach requires extensive imaging and detailed calculations of the amount of water inside and outside brain tissues to standardize these measures, a costly and time-consuming approach.

To address this difficulty, Grant and study co-author Borjan Gagoski, a radiology instructor at Boston Children's Hospital, used proton MRS to scan the brains of 140 infants at approximately one month and three months of age. In addition to using water as a reference, the team also compiled data from several key metabolites in their calculations. This allowed them to create a tool that makes use of standard values for several metabolites when assessing the concentration of any one metabolite in an infant's brain.

"What most everybody does is they look at a simple ratio between metabolite 1 and metabolite 2," Larsen said. "But if that ratio is low, does that mean that metabolite 1 is low or that metabolite 2 is high? It becomes a problem of interpretation."

Instead, the team painstakingly assessed relationships between seven key metabolites to build a database of normal values for each one at different time points, and to show how metabolite concentrations change in relation to one another as the infant's brain develops.

The tool the team developed offers a checklist of reference brain metabolites that users can select in different combinations to more clearly understand an individual infant's profile.

"Spectroscopy is really tough to do but when it's done in the right way, it can help us find out more about the brain," Gagoski said. "This approach has great potential because we can detect abnormalities and diseases before we can actually see anything on the structural scans. And it's really important to monitor brain health at this stage of life."

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This work is funded by Abbott through the Center for Nutrition, Learning, and Memory at the University of Illinois Urbana-Champaign.

A video explaining how to use the new tool, "Introduction to a database of magnetic resonance spectroscopy results from infants scanned at Boston Children's Hospital," is available here.

The paper "Quantification of magnetic resonance spectroscopy data using a combined reference: Application in typically developing infants" is available from the U. of I. News Bureau.

Kratom use rare, but more common among people with opioid use disorder

Substance used by 0.7% of US population and 10.3% of people with opioid use disorder

NEW YORK UNIVERSITY

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Less than one percent of people in the United States use kratom, a plant-based substance commonly used to manage pain and opioid withdrawal, according to a study published in the American Journal of Preventive Medicine. However, the use of kratom--which is legal but carries the risk of addiction and harmful side effects--is more prevalent among people who use other drugs, particularly those with opioid use disorder.

Derived from a tree native to Southeast Asia, kratom can be taken as a pill, capsule, or extract, or brewed as a tea. It acts on the brain's opioid receptors; at low doses, kratom is a stimulant, while at higher doses, it can relieve pain. Some people report using kratom as a substitute for opioids in an effort to limit their opioid use and ameliorate withdrawal. Others use kratom recreationally for relaxation or to self-treat pain, anxiety, or depression.

Kratom is legal at the federal level and in most states, but safety concerns have led to multiple warnings from the U.S. Food and Drug Administration and the Drug Enforcement Administration identifying it as a "drug of concern." Long-term or frequent use can lead to dependence, and adverse events, ranging from mild to severe, have been reported. Kratom has been linked to thousands of poisonings and hundreds of deaths in the U.S., although most involve the use of other drugs, especially opioids.

"Few national studies have examined kratom use among the general population, and such studies can give us a better idea regarding who has been using the substance," said study author Joseph Palamar, PhD, MPH, an associate professor of population health at NYU Grossman School of Medicine and an affiliated researcher with the Center for Drug Use and HIV/HCV Research (CDUHR) at NYU School of Global Public Health.

Using the 2019 National Survey on Drug Use and Health, which captured data on 56,136 adolescents and adults in the U.S., Palamar examined how many people use kratom and what other substances they use. He found that an estimated 0.7 percent of adults and adolescents used kratom in the past year.

Kratom use was more prevalent among people who use other drugs, including cannabis, stimulants, and cocaine, and was particularly common among those who misuse prescription opioids, with 10.3 percent of people with opioid use disorder reporting kratom use.

Men, white people, and those with depression and serious mental illness were also more likely to report using kratom. Teens and adults over 50 were less likely to report use.

"This study adds to our understanding of kratom's prevalence and its connection to opioid misuse," said Palamar. "More research is needed to determine the substance's effectiveness in treating opioid withdrawal, and more research is needed to determine how safe this substance is when combined with other drugs."

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The research was supported by the National Institute on Drug Abuse, part of the National Institutes of Health (R01DA044207).

About CDUHR

The mission of the Center for Drug Use and HIV/HCV Research (CDUHR) is to end the HIV and HCV epidemics in drug using populations and their communities by conducting transdisciplinary research and disseminating its findings to inform programmatic, policy, and grass roots initiatives at the local, state, national, and global levels. CDUHR is a Core Center of Excellence funded by the National Institute on Drug Abuse (Grant #P30 DA011041). It is the first center for the socio-behavioral study of substance use and HIV in the United States and is located at the NYU School of Global Public Health. For more information, visit http://www.cduhr.org.

About NYU Langone Health

NYU Langone Health is a world-class, patient-centered, integrated academic medical center, known for its excellence in clinical care, research, and education. Included in the 260+ locations throughout the New York area are six inpatient locations: Tisch Hospital, its flagship acute-care facility in Manhattan; Rusk Rehabilitation, ranked as one of the top 10 rehabilitation programs in the country; NYU Langone Orthopedic Hospital, a dedicated inpatient orthopedic hospital in Manhattan with all musculoskeletal specialties ranked top 10 in the country; Hassenfeld Children's Hospital at NYU Langone, a comprehensive pediatric hospital, also in Manhattan, supporting a full array of children's health services; NYU Langone Hospital--Brooklyn, a full-service teaching hospital and level 1 trauma center located in Sunset Park, Brooklyn; and NYU Langone Hospital--Long Island, a full-service teaching hospital and level 1 trauma center located in Nassau County on Long Island. Also part of NYU Langone Health is the Laura and Isaac Perlmutter Cancer Center, a National Cancer Institute-designated comprehensive cancer center; NYU Grossman School of Medicine, which since 1841 has trained thousands of physicians and scientists who have helped to shape the course of medical history; and NYU Long Island School of Medicine. For more information, go to nyulangone.org, and interact with us on Facebook, Twitter, YouTube, and Instagram.

About NYU School of Global Public Health

At the NYU School of Global Public Health (NYU GPH), we are preparing the next generation of public health pioneers with the critical thinking skills, acumen, and entrepreneurial approaches necessary to reinvent the public health paradigm. Devoted to employing a nontraditional, interdisciplinary model, NYU GPH aims to improve health worldwide through a unique blend of global public health studies, research, and practice. The School is located in the heart of New York City and extends to NYU's global network on six continents. Innovation is at the core of our ambitious approach, thinking and teaching. For more, visit: http://publichealth.nyu.edu/

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Treating dental pain with opioids linked to higher risk of overdose in patients & families

Study also shows certain patients have an even greater risk of overdose if they fill opioid prescriptions, and strengthens argument against use of opioids for most dental pain

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

Research News

 

When they go to the dentist to get a tooth pulled or another procedure, patients might not think that the prescription they receive to ease their pain could put them or their family at risk of an opioid overdose.

But a new study from the University of Michigan shows that overdose rates were two and a half times higher among patients who filled a prescription for an opioid medication after a dental procedure, compared with those who didn't fill such a prescription.

Overdose rates were also higher among the family members of such patients - possibly from misuse of the leftover pills.

The study is published in the American Journal of Preventive Medicine by a team from the U-M Medical School and School of Dentistry. It used data from 8.5 million teen and adult patients who had dental procedures between 2011 and 2018, and whose care was covered by Medicaid or private dental insurance. Nearly 27% of these patients filled a prescription for an opioid such as hydrocodone or oxycodone.

The researchers identified 2,700 overdoses that occurred in the 90 days after a tooth extraction or 119 other dental procedures. That works out to about three overdoses for every 10,000 dental procedures. The rate was 5.8 per 10,000 among those who filled an opioid prescription within three days of their procedure, compared with 2.2 per 10,000 among those who didn't.

The researchers note that other data have shown that in 2016 alone, dentists wrote 11.4 million prescriptions for opioids. The new study's findings suggest that 1,700 overdoses a year could be happening because of dental opioid prescriptions.

Risks among family members

The study also used data from 3.5 million privately insured dental procedure patients to examine overdoses within 90 days in the patients' family members. The rate of overdose was 1.7 per 10,000 procedures in family members of privately insured patients who filled opioid prescriptions, compared with 1 per 10,000 procedures among those who didn't.

In the study, 400 family members of patients were treated for opioid overdoses in the 90-day period after the dental patient's procedure. In all, 42% of these overdoses were in the child of the patient who had a procedure, and another 25% were in a spouse; the rest were in parents and siblings.

Kao-Ping Chua, M.D., Ph.D., led the analysis. "Our paper shows that when patients fill dental opioid prescriptions, the risk of opioid overdose increases both for themselves and their family members," he says. "This underscores the importance of avoiding dental opioid prescribing when non-opioids like ibuprofen and acetaminophen are effective options for pain control, as is the case for the majority of dental procedures. Our finding of increased overdose risk in family members also shows the importance of emphasizing safe storage and disposal when prescribing opioids to dental patients."

Chua is a pediatrician at Michigan Medicine, a health care researcher at the Susan B. Meister Child Health Evaluation Research Center, and a member of the U-M Institute for Healthcare Policy and Innovation.

"To me, this is one of the most powerful truths we've unlocked in our 'big data' research on dental opioid prescribing," says senior author Romesh Nalliah, D.D.S., M.H.C.M. "That when a dentist, like me, prescribes an opioid to a patient I am putting their entire family at risk of overdose. Dentists should consider, if the family concerned was yours, would you take that risk?" Nalliah is associate dean for patient services at U-M School of Dentistry and a member of IHPI, and has led other research on dental opioid use.

The authors are part of the Michigan Opioid Prescribing Engagement Network (Michigan OPEN), which has developed guidelines for dentists and surgeons to reduce or eliminate the prescribing of opioids for many procedures and operations, while still providing effective pain relief. Michigan OPEN recommends that dentists avoid prescribing opioids for most dental procedures because non-opioids are just as effective for pain.

Groups at higher risk of overdose after receiving dental opioids

The study also identifies specific groups of dental patients who are at a higher risk of opioid overdose after receiving opioid prescriptions.

Those groups include patients with diagnosed mental health conditions and substance use disorders, and those with Medicaid health coverage.

This knowledge could help dentists and oral surgeons choose the pain treatment for their patients more carefully, and include a prescription for the overdose treatment naloxone if they prescribe opioids to someone with a higher risk of overdose.

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The study was funded by the Benter Foundation, the Substance Abuse and Mental Health Services Administration, U-M Precision Health, and the National Institute on Drug Abuse (DA048110). In addition to Chua and Nalliah, the study's authors are Brooke Kenney, M.P.H., and Michigan-OPEN co-directors Jennifer F. Waljee, M.D., M.S., and Chad M. Brummett, M.D., who are also members of IHP