Saturday, November 25, 2023

Curators & cavers: How a tip from a citizen scientist led to deep discoveries in Utah’s caves


New research from NHMU uses caves to establish benchmarks for recent climate impacts on mammals


Peer-Reviewed Publication

UNIVERSITY OF UTAH




Scientists from the Natural History Museum of Utah have taken a deep dive into the not-so-distant past thanks to a friendly tip from Utah’s caving community. In a paper published this week by the Journal of Mammalogy, five scientists from the Natural History Museum of Utah (NHMU) and colleagues from Utah’s caving community have published the first research from their collaborative field work effort deep in Utah’s caves. 

The journal’s feature article reveals why caves make such compelling research archives; what was uncovered in Boomerang Cave in northern Utah; why skeletal remains provide new access to hard-to-get data from the recent past; and offers a new zoological baseline for mammalian changes in an alpine community.  

“To understand the impacts of climate on alpine ecosystems, we record current mammal species—mostly through trapping. But that method doesn’t tell us anything about the mammalian diversity in the recent past,” said Kaedan O’Brien, lead author and anthropology PhD candidate at the University of Utah. “So not a lot of study has been done on past alpine ecosystems because they are harder to get to, and when you do there is a slim chance of finding older skeletal remains intact.”

In NHMU Chief Curator and paleoecologist Dr. Tyler Faith’s words, “We want to know what animals were there in the 1800s, but that’s nearly impossible in the absence of historical records. How do we document the recent past without a time machine?” An out-of-the-blue email from local caver and study co-author Eric Richards offered an unexpected method of time travel: repelling hundreds of feet down into Utah’s caves to find what may have fallen in—and when.

In early 2019, Richards emailed NHMU Curator of Paleontology Dr. Randy Irmis to ask if he or the museum had any interest in the animal bones that he’d been finding on Utah cave adventures, and he sent photographs. Irmis replied right away, including colleague Dr. Tyler Faith and O’Brien, a PhD student in Faith’s lab. The group met, hit it off, and after a couple of trial outings for equipment training, Faith and Irmis were lowering themselves into caves to collect bones of by-gone animals.

“To be clear, this project would have never happened without the cavers reaching out to us, and investing time, and training with us. Eric and his wife Fumiko literally ‘showed us the ropes.’” said Faith. “I hope people realize that research isn’t just done by scientists who work at the museum, it can be public collaboration—in this case with trained experts (do not try this at home).”

After Faith obtained a research permit from the U.S. Forest Service in September 2019, Richards took the team to Boomerang Cave in the Bear River Range where they collected specimens for lab analysis at the museum. O’Brien managed the lion’s share of that work, upon which the paper is based. 

“Identifying skeletal remains is painstaking work, because you just go bone by bone, sorting by size and element, and then comparing them with regional museum voucher specimens,” said O’Brien. But the result is exciting. 

Using radiocarbon dating, fossils found in Boomerang Cave were shown to span the past 3,000 years, with the bulk from the last 1000 years or so. Comparison of these fossils to museum records and present-day mammals collected by co-authors and NHMU zoologists, Dr. Eric Rickart and Katrina Derieg, showed that the cave provided a faithful reflection of mammal diversity in the area. Perhaps most exciting is that the fossils also revealed the presence of species unknown to the region, like Merriam’s shrew. The full list of fossils is in the current Journal of Mammalogy, along with more on why this research matters.

“Our work highlights the value of collecting skeletal remains from caves as a convenient and accurate method for understanding the mammal communities” said Irmis. “Caves help us create comprehensive and long-term records and better understand how animals have changed in the recent past.”

Faith, Irmis, and O’Brien credit the ongoing success of this research to the curiosity and generosity of Utah’s caving community. It’s another example of citizen science advancing research and developing long-term relationships between NHMU and the public. To learn more about citizen science opportunities with NHMU, please visit nhmu.utah.edu/citizen-science.

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About the Natural History Museum of Utah  

The Natural History Museum of Utah is one of the leading scientific research and cultural institutions in the country. Established in 1963, the museum’s 10 permanent exhibitions are anchored by its state-of-the-art collections and research facilities containing almost 2 million objects. These collections are used in studies on geological, biological, and cultural diversity, and the history of living systems and human cultures within the Utah region. The museum hosts approximately 300,000 general visitors a year and provides one of the most spectacular private event settings in the Salt Lake City area. NHMU also broadens the reach of its mission through a variety of science-based outreach programs to communities and schools throughout Utah, reaching every school district in the state every other year.

 

Coastal river deltas threatened by more than climate change


Peer-Reviewed Publication

LUND UNIVERSITY

 




Worldwide, coastal river deltas are home to more than half a billion people, supporting fisheries, agriculture, cities, and fertile ecosystems. In a unique study covering 49 deltas globally, researchers from Lund University and Utrecht University have identified the most critical risks to deltas in the future. The research shows that deltas face multiple risks, and that population growth and poor environmental governance might pose bigger threats than climate change to the sustainability of Asian and African deltas, in particular.

“We can clearly show that many risks are not linked to climate. While climate change is a global problem, other important risk factors like land subsidence, population density and ineffective governance are local problems. Risks to deltas will only increase over time, so now is the time for governments to take action”, says Murray Scown, associate senior lecturer, Lund University Centre for Sustainability Studies, and lead author.

Collapse of delta environments could have huge consequences for global sustainable development. In the worst-case scenario, deltas could be lost to the sea; other consequences are flooding, salinization of water, which affects agriculture, coastal squeeze, and loss of ecosystems.

The study, published in Global Environmental Change, looked at five different IPCC scenarios for global development in 49 deltas all over the world, including famous deltas such as the Nile, Mekong, and Mississippi, but also more understudied deltas such as the Volta, Zambezi and Irrawaddy deltas. The research identifies possible risks to deltas stretching 80 years into the future. The researchers based their analysis on 13 well-known factors affecting risk in deltas and drew upon unique models to identify which of these risks are most likely to endanger different deltas in the future. Risk factors include increasing population density, urban development, irrigated agriculture, changes to river discharge, land subsidence and relative sea-level rise, limited economic capacity, poor government effectiveness, and low adaptation readiness.

Population density, land subsidence and ineffective governance are high risk factors

The analysis shows that there are some risks that are more critical to deltas than others – in all of the five future scenarios. These include land subsidence and relative sea-level rise, population density, ineffective governance, economic capacity, and crop land use. 

For some deltas, physical risks are especially pronounced. Land subsidence is, for example, the highest risk factor for the Mekong delta in Vietnam. Extreme sea levels are among the most concerning risk factors for deltas in China, on the Korean peninsula, and in the Colorado (Mexico) and Rhine (Netherlands) deltas. 

In the Nile (Egypt), Niger (Nigeria), and the Ganges (Bangladesh) deltas, it is increasing population density that is of most concern under certain scenarios. For other deltas, it is the lack of economic capacity and government effectiveness to manage risks, for example in the Irrawaddy (Myanmar) and Congo (Angola and Democratic Republic of the Congo) deltas. 

“Analysed all together, we can see that the Asian mega-deltas are at greatest risk, with potentially devastating consequences for millions of people, and for the environment. They are under pressure from population growth, intense agricultural land use, relative sea-level rise, and lagging adaptation readiness”, says Murray Scown.

Local and global approaches and a mixture of hard and soft adaptation can mitigate risks 

“Instead of sitting back, governments need to think long-term, and put plans in place to reduce or mitigate risks. In the Mekong delta, for example, the Vietnamese government are making strong efforts to restrict future groundwater extraction in the delta to reduce land subsidence and salinization”, says Philip Minderhoud, assistant professor at Wageningen University and Research.

The researchers highlight that a mixture of hard (“grey”) and soft (“green”) adaptation approaches will be required to manage and mitigate delta risks. They include both hard infrastructures, like sea walls to stop the sea inundating the delta, and soft approaches using nature-based solutions. One example is the Dutch experience of creating room for the river in the Rhine delta, by lowering floodplains, relocating levees, and using spaces that are allowed to flood for grazing. Initiatives to build up delta surfaces by allowing rivers to flood and deposit sediment on the delta to maintain elevation above sea level are also promising, notes Frances Dunn, assistant professor at Utrecht University.

“By looking at the deltas together, like we have in this study, we want to highlight what can happen on a global scale if we do not address delta risk both on a local and global level. The study can also complement studies on individual deltas, and identify efforts needed connected to less studied deltas such as the Saõ Francisco or Volta delta”, says Maria Santos, professor at the University of Zurich.

 

Study provides fresh insights into antibiotic resistance, fitness landscapes

Peer-Reviewed Publication

SANTA FE INSTITUTE




E. coli bacteria may be far more capable at evolving antibiotic resistance than scientists previously thought, according to a new study published in Science on November 24.

Led by SFI External Professor Andreas Wagner, the researchers experimentally mapped more than 260,000 possible mutations of an E. coli protein that is essential for the bacteria’s survival when exposed to the antibiotic trimethoprim.

Over the course of thousands of highly realistic digital simulations, the researchers then found that 75% of all possible evolutionary paths of the E. coli protein ultimately endowed the bacteria with such a high level of antibiotic resistance that a clinician would no longer give the antibiotic trimethoprim to a patient.

“In essence, this study suggests that bacteria like E. coli may be more adept at evolving resistance to antibiotics than we initially thought, and this has broader implications for understanding how various systems in evolutionary biology, chemistry, and other fields adapt and evolve,” says Wagner, an evolutionary biologist at the University of Zurich in Switzerland.

Besides uncovering new and potentially worrisome findings about antibiotic resistance, the researchers’ work also casts doubt on a longstanding theory about fitness landscapes. These genetic maps represent how well an organism — or a part of it, like a protein — adapts to its environment.

On fitness landscapes, different points on the landscape represent different genotypes of an organism, and the height of these points represents how well each genotype is adapted to its environment. In evolutionary biology terms, the goal is to find the highest peak, which indicates the fittest genotype.

Prevailing theory regarding fitness landscapes predicts that in highly rugged landscapes, or those with multiple peaks of fitness, most evolving populations will become trapped at lower peaks and never reach the pinnacle of evolutionary adaptation.

However, testing this theory has been exceedingly difficult until now due to the lack of experimental data on sufficiently large fitness landscapes.

To address this challenge, Wagner and colleagues used CRISPR gene editing technology to create one of the most combinatorially complete fitness landscapes to date for the E. coli dihydrofolate reductase (DHFR) protein.

What they found was surprising. The landscape had many peaks, but most were of low fitness, making them less interesting for adaptation. However, even in this rugged landscape, about 75% of the populations they simulated reached high fitness peaks, which would grant E. coli high antibiotic resistance.

The real-world implications are significant. If rugged landscapes like this are common in biological systems, it could mean that many adaptive processes, such as antibiotic resistance, may be more accessible than previously thought.

The result could ultimately lead to a re-evaluation of theoretical models in various fields and prompt further research into how real-world landscapes impact evolutionary processes.

“This has profound implications not only in biology but beyond, prompting us to reevaluate our understanding of landscape evolution across various fields,” Wagner says. “We need to shift from abstract theoretical models to data-informed, realistic landscape models.”

 

Premature death of autistic people in the UK investigated for the first time


Peer reviewed | Observational study | People

Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON




A new study led by UCL researchers confirms that autistic people experience a reduced life expectancy, however the number of years of life lost may not be as high as previously claimed.

The research, published in The Lancet Regional Health – Europe, is the first to estimate the life expectancy and years of life lost by autistic people living in the UK.

The team used anonymised data from GP practices throughout the UK to study people who received an autism diagnosis between 1989 to 2019. They studied 17,130 people diagnosed as autistic without a learning disability and 6,450 participants diagnosed as autistic with a learning disability. They then compared these groups with people of the same age and sex, who had not been diagnosed as autistic.

The researchers found that autistic men without a learning disability had an average estimated life expectancy of 74.6 years, and autistic women without a learning disability, around 76.8 years. 

Meanwhile, the estimated life expectancy for people diagnosed with autism and learning disability was around 71.7 years for men and 69.6 years for women.

These figures compare to the usual life expectancy of around 80 years for men and around 83 years for women living in the UK.

The findings provide the first evidence that diagnosed autistic people were more likely to die prematurely in the UK across the time period studied, indicating an urgent need to address inequalities that disproportionately affect autistic people.

However, the new estimates also suggest that the widely reported statistic that autistic people live 16 years less on average* is likely to be incorrect.

Lead investigator of the study, Professor Josh Stott (UCL Psychology & Language Sciences), said: “Autism itself does not, to our knowledge, directly reduce life expectancy, but we know that autistic people experience health inequalities, meaning that they often don’t get the support and help that they need when they need it. We wanted to explore whether this impacted the average life expectancy for diagnosed autistic people living in the UK.

“Our findings show that some autistic people were dying prematurely, which impacted the overall life expectancy. However, we know that when they have the right support, many autistic people live long, healthy and happy lives. Although our findings show important inequalities, we were concerned about frightening statistics that are often quoted, and it is important to provide more realistic information.

“We do need to find out why some autistic people are dying prematurely so that we can identify ways to prevent this from happening.”

Autistic people have differences in their social communication and social interaction, alongside restricted and repetitive patterns of behaviours, interests and activities.

Many autistic people require adjustments to be made to ensure equal access to healthcare, employment, and local authority support.

Some autistic people also have learning disabilities, and can find it hard to explain to others when they are experiencing pain or discomfort. This can mean that health problems go undetected.

There are numerous reports of social exclusion, difficulties accessing support, and inappropriate care being given, as described in Baroness Hollins’ report that was published earlier in November**.

Joint-lead author, Dr Elizabeth O’Nions (UCL Psychology & Language Sciences), said: “Autistic people are rightly and increasingly pushing for recognition that autism reflects natural and expected variation in how brains function, and that society must make space for all.

“This means that services must be inclusive and accommodating of those who have particular support needs by adapting how they operate.

“We believe that the findings of this study reflect inequalities that disproportionately affect autistic people.”

The researchers have previously published a study, which found that the true number of autistic people in England may be more than double the number often cited in national health policy documents***.

Consequently, they acknowledge that the new research may over-estimate the reduction in life expectancy experienced by autistic people on average.

Professor Stott said: “Very few autistic adults have been diagnosed, meaning that this study only focuses on a fraction of the total autistic population.

“Those who are diagnosed may be those with greater support needs and more co-occurring health conditions than autistic people on average.

“We think this is particularly the case for women diagnosed with autism and learning disability - the larger reduction in life expectancy may reflect a disproportionate underdiagnosis of autism and/or learning disability in women.

“It’s likely that not all autistic people experience a reduced life expectancy – indeed, some autistic people may be better at sticking to healthy routines than average, potentially increasing their life expectancy.”

Dr Judith Brown, Head of Evidence and Research at the National Autistic Society, said: “This is very important research led by University College London and we are grateful to have been able to contribute.

“While the results of this study suggest a smaller difference than previously understood between the life expectancy of autistic and non-autistic people, they are still significant. These findings demonstrate that autistic people continue to face unacceptable inequalities through a lack of understanding, barriers to vital services and inadequate care, which lead to poorer mental and physical health outcomes.

“Without investment, improved understanding, inclusion and the correct level of support and care, autistic people will continue to see reduced life expectancy, with the most at-risk group in this study being autistic women with learning disabilities. This research should be a wake-up call for Government, the NHS, healthcare professionals and society as a whole that we must tackle the health inequality autistic people face.”

The research was funded by the Dunhill Medical Trust, Medical Research Council, National Institute for Health and Care Research, and the Royal College of Psychiatrists.

*https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/lifeexpectancies/qmis/nationallifetablesqmi

**https://www.gov.uk/government/publications/independent-care-education-and-treatment-reviews-final-report-2023/baroness-hollins-final-report-my-heart-breaks-solitary-confinement-in-hospital-has-no-therapeutic-benefit-for-people-with-a-learning-disability-an

*** https://www.ucl.ac.uk/news/2023/jun/number-autistic-people-england-may-be-twice-high-previously-thought

 

Drones enabled the use of defibrillators before ambulance arrival


Peer-Reviewed Publication

KAROLINSKA INSTITUTET

Andreas Claesson 

IMAGE: 

ANDREAS CLAESSON

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CREDIT: EUROPEAN SOCIETY OF CARDIOLOGY




Researchers at Karolinska Institutet have evaluated the possibility of alerting drones equipped with automated external defibrillators (AED) to patients with suspected cardiac arrest. In more than half of the cases, the drones were ahead of the ambulance by an average of three minutes. In cases where the patient was in cardiac arrest, the drone-delivered defibrillator was used in a majority of cases. The results have been published in the journal The Lancet Digital Health.   

"The use of an AED is the single most important factor in saving lives. We have been deploying drones equipped with AED since the summer of 2020 and show in this follow-up study that drones can arrive at the scene before an ambulance by several minutes. This lead time has meant that the AED could be used by people at the scene in several cases," says Andreas Claesson, Associate Professor at the Center for Cardiac Arrest Research at the Department of Clinical Research and Education, Södersjukhuset, Karolinska Institutet, and principal investigator of the study.   

Every year, around 6000 people in Sweden suffer a sudden cardiac arrest, but only a tenth of those affected survive. Although an early shock with a AED can dramatically increase the chance of survival and there are tens of thousands of AED in the community, they are not available in people's homes where most cardiac arrests occur.   

To shorten the time to defibrillation with an AED, Karolinska Institutet, together with Region Västra Götaland, SOS Alarm and the drone operator Everdrone, has since 2020 tested the possibility of sending out a drone with a AED at the same time as an ambulance is alerted. The project covered an area of approximately 200,000 people in western Sweden. An initial study conducted in the summer of 2020 in Gothenburg and Kungälv showed that the idea was feasible and safe.    

“This more comprehensive and follow-up study now shows in a larger material that the methodology works throughout the year, summer and winter, in daylight and darkness. Drones can be alerted, arrive, deliver AED, and people on site have time to use the AED before the ambulance arrives," says Sofia Schierbeck, PhD student at the same department and first author of the study.   

In the study, drones delivered a AED in 55 cases of suspected cardiac arrest. In 37 of these cases, the delivery took place before an ambulance, corresponding to 67 percent, with a median lead of 3 minutes and 14 seconds. In the 18 cases of actual cardiac arrest, the caller managed to use the AED in six cases, representing 33 percent. A shock was recommended by the device in two cases and in one case the patient survived.   

“Our study now shows once and for all that it is possible to deliver AED with drones and that this can be done several minutes before the arrival of the ambulance in connection with acute cardiac arrest," says Andreas Claesson. “This time saving meant that the healthcare emergency center could instruct the person who called the ambulance to retrieve and use the AED in several cases before the ambulance arrived."  

The research was mainly funded by the Swedish Heart-Lung Foundation.  

Publication: "Drone delivery of automated external defibrillators compared with ambulance arrival in real-life suspected out-of-hospital cardiac arrests: a prospective observational study in Sweden", Sofia Schierbeck, A Nord, L Svensson, M Ringh, P Nordberg, J Hollenberg, P Lundgren, F Folke, M Jonsson, S Forsberg, A Claesson, The Lancet digital health, online November 23, 2023, doi: 10.1016/S2589-7500(23)00161-9 

 

Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests


Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - LOS ANGELES HEALTH SCIENCES




Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests

New research finds little evidence that post-surgical patient mortality is lower when patient and surgeon are the same gender.

While gender concordance has been shown to improve patient care in other health specialties, evidence has been limited when it comes to concordance between patient and surgeon. This study shows that gender concordance was associated with lower mortality for female patients, but higher mortality for male patients—patient mortality was the lowest for female patients treated by female surgeons, and the highest for male patients treated by male surgeons.

This study also investigated the impact of surgeon gender, and shows that female surgeons had slightly lower patient mortality than males for elective surgeries, but no gender difference for non-elective procedures.

The findings will be published in the peer-reviewed journal The BMJ.

“It is important for patients to know that the quality of surgical care provided by female surgeons in the United States is equivalent to, or in some cases, slightly better than that provided by male surgeons,” said senior author Dr. Yusuke Tsugawa, associate professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA. “Given that the difference in patient mortality between female and male surgeons was small, when choosing a surgeon, patients should take into account factors beyond the gender of the surgeon.”

The researchers examined data for 2.9 million Medicare fee-for-service beneficiaries aged 65 years and older who underwent one of 14 surgeries between 2016 and 2019: abdominal aortic aneurysm repair, appendectomy, cholecystectomy, colectomy, coronary artery bypass surgery, knee replacement, hip replacement, hysterectomy, laminectomy or spinal fusion, liver resection, lung resection, prostatectomy, radical cystectomy, and thyroidectomy.

Of the participants, 1.2 million (41%) were male surgeon/patient pairs, 86,000 (3%) were female pairs, and 1.6 million (56%) were pairs of different genders (52,000, or 1.8%, were male patient/female surgeon and 1.5 million, or 54%, female patient/male surgeon). The outcome measure was death within 30 days of the procedure.

Adjusting for patient and surgeon characteristics and other factors, the researchers found that 30 day post-surgery mortality was 2.0% for male patient-male surgeon, 1.7% for male patient-female surgeon, 1.5% for female patient-male surgeon, and 1.3% for female patient-female surgeon pairs.

Study limitations include potential undetected confounders from Medicare claims data, an inability to account for contributory characteristics of other healthcare team members, and the possibility that the findings may not apply to younger patients.

But the findings could lead to a better understanding of processes that improve care for all patients, the researchers write. “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery,” they write.

Study co-authors are Ryo Ikesu, Dr. Melinda Maggard-Gibbons, and Ruixin Li of UCLA; Christopher Wallis, Angela Jerath, Dr. Natalie Coburn, and Allan Detsky, of the University of Toronto; Raj Satkunasivam of Texas A&M University and Houston Methodist Hospital; Justin Dimick of University of Michigan; E. John Orav of Harvard University; Arghavan Salles of Stanford University; Zachary Klaassen of Georgia-Augusta University, and Barbara Bass of George Washington University.

This study was funded by the National Institute of Health (NIH)/National Institute on Minority Health and Health Disparities (R01 MD013913) and Gregory Annenberg Weingarten GRoW @Annenberg.

Does patient-surgeon gender concordance lead to lower patient mortality? Mostly no, UCLA-led research suggests

New research finds little evidence that post-surgical patient mortality is lower when patient and surgeon are the same gender.

While gender concordance has been shown to improve patient care in other health specialties, evidence has been limited when it comes to concordance between patient and surgeon. This study shows that gender concordance was associated with lower mortality for female patients, but higher mortality for male patients—patient mortality was the lowest for female patients treated by female surgeons, and the highest for male patients treated by male surgeons.

This study also investigated the impact of surgeon gender, and shows that female surgeons had slightly lower patient mortality than males for elective surgeries, but no gender difference for non-elective procedures.

The findings will be published in the peer-reviewed journal The BMJ.

“It is important for patients to know that the quality of surgical care provided by female surgeons in the United States is equivalent to, or in some cases, slightly better than that provided by male surgeons,” said senior author Dr. Yusuke Tsugawa, associate professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA. “Given that the difference in patient mortality between female and male surgeons was small, when choosing a surgeon, patients should take into account factors beyond the gender of the surgeon.”

The researchers examined data for 2.9 million Medicare fee-for-service beneficiaries aged 65 years and older who underwent one of 14 surgeries between 2016 and 2019: abdominal aortic aneurysm repair, appendectomy, cholecystectomy, colectomy, coronary artery bypass surgery, knee replacement, hip replacement, hysterectomy, laminectomy or spinal fusion, liver resection, lung resection, prostatectomy, radical cystectomy, and thyroidectomy.

Of the participants, 1.2 million (41%) were male surgeon/patient pairs, 86,000 (3%) were female pairs, and 1.6 million (56%) were pairs of different genders (52,000, or 1.8%, were male patient/female surgeon and 1.5 million, or 54%, female patient/male surgeon). The outcome measure was death within 30 days of the procedure.

Adjusting for patient and surgeon characteristics and other factors, the researchers found that 30 day post-surgery mortality was 2.0% for male patient-male surgeon, 1.7% for male patient-female surgeon, 1.5% for female patient-male surgeon, and 1.3% for female patient-female surgeon pairs.

Study limitations include potential undetected confounders from Medicare claims data, an inability to account for contributory characteristics of other healthcare team members, and the possibility that the findings may not apply to younger patients.

But the findings could lead to a better understanding of processes that improve care for all patients, the researchers write. “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery,” they write.

Study co-authors are Ryo Ikesu, Dr. Melinda Maggard-Gibbons, and Ruixin Li of UCLA; Christopher Wallis, Angela Jerath, Dr. Natalie Coburn, and Allan Detsky, of the University of Toronto; Raj Satkunasivam of Texas A&M University and Houston Methodist Hospital; Justin Dimick of University of Michigan; E. John Orav of Harvard University; Arghavan Salles of Stanford University; Zachary Klaassen of Georgia-Augusta University, and Barbara Bass of George Washington University.

This study was funded by the National Institute of Health (NIH)/National Institute on Minority Health and Health Disparities (R01 MD013913) and Gregory Annenberg Weingarten GRoW @Annenberg.


Death rates after surgery similar regardless of patient-surgeon gender match

Findings should help improve processes and patterns of care for all patients

Peer-Reviewed Publication

BMJ

Death rates after major surgery are similar regardless of whether a male or female surgeon operates on a male or female patient, finds a large US study published by The BMJ today.

The differences seen were small and not clinically meaningful and the researchers say their findings should help improve processes and patterns of care for all patients.

Gender concordance between patients and physicians (when the physician and patient are of the same sex) is generally linked to higher quality care processes and improved patient outcomes through more effective communication, reduced (implicit and explicit) sex and gender bias, and better rapport.

But evidence is limited about the effect of patient and surgeon gender concordance on outcomes of patients undergoing a surgical procedure.

To address this, researchers set out to determine whether patient-surgeon gender concordance is associated with death after surgery in the United States. 

Their theory was that patients treated by surgeons of the same gender would have a lower postoperative death rate than patients treated by gender discordant surgeons.

They analysed data for almost 3 million Medicare patients aged 65-99 years who underwent one of 14 common major urgent or non-urgent (elective) surgeries between 2016 and 2019 including coronary artery bypass surgery, knee or hip replacement, hysterectomy, liver or lung resection, and thyroidectomy.

Death after surgery was defined as death within 30 days of the operation.

Adjustments were made for patient characteristics (such as age, race and underlying conditions), surgeon characteristics (such as age, years in practice and number of operations performed) and hospital fixed effects (effectively comparing patients within the same hospital).

Of 2,902,756 patients who had surgery, 1,287,845 (44%) had operations done by surgeons of the same gender (1,201,712 (41%) male patient and male surgeon and 86,133 (3%) female patient and female surgeon) and 1,614,911 (56%) were by surgeons of different gender (52,944 (1.8%) male patient and female surgeon and  1,561,967 (54%) female patient and male surgeon). 

For urgent and elective procedures combined, the adjusted death rate 30 days after surgery was 2% for male patients treated by male surgeons, 1.7% for male patients treated by female surgeons, 1.5% for female patients treated by male surgeons, and 1.3% for female patients treated by female surgeons.

For elective procedures, female surgeons had slightly lower patient death rates (0.5%) than male surgeons (0.8%), whereas no difference in patient mortality was seen for urgent surgeries.

Several mechanisms could explain this small effect for elective procedures, say the authors. For example, female surgeons may abide by clinical guidelines more than male surgeons, or might have better communication and increased attention to postoperative care than male surgeons, which could affect patient death rates. 

What’s more, as elective surgeries allow patients to choose their own surgeon, they are more prone to influence from other factors compared with urgent procedures where patients are assigned to on-call surgeons, they add.

This is an observational study, so can’t establish cause, and the researchers stress that other unmeasured social and cultural factors may have influenced their results. What’s more, they say their findings may not apply to younger populations, patients who receive less common procedures, or patients in other countries.

Nevertheless, they say understanding the underlying mechanisms of this observation “allows the opportunity to improve processes and patterns of care for all patients.”

They add: “Ongoing qualitative and quantitative research will better delineate how surgeon and patient gender, along with race and other aspects of shared identity, affect quality of care and outcomes after surgery.”