Share of patients with heat exhaustion increased 53 percent when comparing June 2016 to June 2021
More males than females diagnosed with heat-related illnesses, according to new FAIR Health study
Reports and ProceedingsNEW YORK, NY—December 13, 2022—Among privately insured individuals receiving medical services, the percentage of patients diagnosed with heat exhaustion increased 52.5 percent when comparing June 2016 to June 2021. This was part of a general trend in which, from May to September, the percentage of patients who were diagnosed with heat stress, heat exhaustion or heatstroke was higher in each month in 2021 than in the corresponding month of 2016. These and other findings are reported in a FAIR Health brief released today, Heat-Related Illness: A Window into Recent Trends.
In the context of other researchers’ projections that rising summer temperatures will be a source of adverse health impacts from climate change, FAIR Health drew on its repository of more than 39 billion private healthcare claim records—the nation’s largest such repository—to analyze recent trends and patterns in heat-related illnesses in the United States. Three types of heat-related illness—in order of increasing severity, heat stress, heat exhaustion and heatstroke—were examined in the period from May through September for the years 2016-2021. Changes in percent of patients diagnosed, as well as their age and gender, were studied for each type of illness. Among the key findings:
- In the months from May through September, the greatest increase in percent of patients diagnosed for heatstroke was 40.1 percent when comparing September 2016 to September 2021. The greatest increase for heat stress was 37.8 percent when comparing May 2016 to May 2021.
- The percentage of patients with heat stress, heat exhaustion or heatstroke diagnoses increased with age, with the greatest percentage found in the age group 65 years and older. Of patients who received medical services nationally in the 65-and-older population, 2.61 percent had a diagnosis of heat exhaustion, 1.93 percent had a diagnosis of heat stress and 0.70 percent had a diagnosis of heatstroke.
- More males than females were diagnosed with the three heat-related illnesses studied. Though the distribution was close for heat stress (males 52 percent, females 48 percent), there was greater gender disparity for heat exhaustion and heatstroke. For each of these diagnoses, males constituted 64 percent and females constituted 36 percent.
- Age was a factor in whether males or females were more likely to be diagnosed with heat stress. In individuals 36 years and older, males were more likely than females to be diagnosed; in individuals 35 years and younger, females were more likely than males to be diagnosed with heat stress. For heat exhaustion and heatstroke, males were more likely than females to be diagnosed in every age group.
- For all three heat-related illnesses studied, the largest disparity between males and females in percentage of diagnoses was in the age group 55 to 64.
FAIR Health President Robin Gelburd stated: “The findings in this report have implications for all healthcare stakeholders concerned with heat-related illnesses, including patients, providers, payors and policy makers. FAIR Health hopes that these findings will also be starting points for further research on heat-related illnesses.”
For the complete brief, click here.
Follow us on Twitter @FAIRHealth
More males than females diagnosed with heat-related illnesses, according to new FAIR Health study
Reports and ProceedingsNEW YORK, NY—December 13, 2022—Among privately insured individuals receiving medical services, the percentage of patients diagnosed with heat exhaustion increased 52.5 percent when comparing June 2016 to June 2021. This was part of a general trend in which, from May to September, the percentage of patients who were diagnosed with heat stress, heat exhaustion or heatstroke was higher in each month in 2021 than in the corresponding month of 2016. These and other findings are reported in a FAIR Health brief released today, Heat-Related Illness: A Window into Recent Trends.
In the context of other researchers’ projections that rising summer temperatures will be a source of adverse health impacts from climate change, FAIR Health drew on its repository of more than 39 billion private healthcare claim records—the nation’s largest such repository—to analyze recent trends and patterns in heat-related illnesses in the United States. Three types of heat-related illness—in order of increasing severity, heat stress, heat exhaustion and heatstroke—were examined in the period from May through September for the years 2016-2021. Changes in percent of patients diagnosed, as well as their age and gender, were studied for each type of illness. Among the key findings:
- In the months from May through September, the greatest increase in percent of patients diagnosed for heatstroke was 40.1 percent when comparing September 2016 to September 2021. The greatest increase for heat stress was 37.8 percent when comparing May 2016 to May 2021.
- The percentage of patients with heat stress, heat exhaustion or heatstroke diagnoses increased with age, with the greatest percentage found in the age group 65 years and older. Of patients who received medical services nationally in the 65-and-older population, 2.61 percent had a diagnosis of heat exhaustion, 1.93 percent had a diagnosis of heat stress and 0.70 percent had a diagnosis of heatstroke.
- More males than females were diagnosed with the three heat-related illnesses studied. Though the distribution was close for heat stress (males 52 percent, females 48 percent), there was greater gender disparity for heat exhaustion and heatstroke. For each of these diagnoses, males constituted 64 percent and females constituted 36 percent.
- Age was a factor in whether males or females were more likely to be diagnosed with heat stress. In individuals 36 years and older, males were more likely than females to be diagnosed; in individuals 35 years and younger, females were more likely than males to be diagnosed with heat stress. For heat exhaustion and heatstroke, males were more likely than females to be diagnosed in every age group.
- For all three heat-related illnesses studied, the largest disparity between males and females in percentage of diagnoses was in the age group 55 to 64.
FAIR Health President Robin Gelburd stated: “The findings in this report have implications for all healthcare stakeholders concerned with heat-related illnesses, including patients, providers, payors and policy makers. FAIR Health hopes that these findings will also be starting points for further research on heat-related illnesses.”
For the complete brief, click here.
Follow us on Twitter @FAIRHealth
About 1 in 100 heart disease deaths linked to extreme hot and cold weather days
International analysis suggests extreme temperatures increase risk of heart failure deaths, pointing to need for mitigating strategies in era of climate change
Peer-Reviewed PublicationIMAGE: THIS GRAPH SHOWS TEMPERATURE PERCENTILES AND RELATIVE RISK OF DYING FROM HEART DISEASE IN 567 COUNTRIES. DASHED LINE REPRESENTS TEMPERATURES ASSOCIATED WITH LOWEST RISK OF DEATH. DOTTED LINES REPRESENT 1ST PERCENTILE (EXTREME COLD) AND 99TH PERCENTILE (EXTREME HEAT). view more
CREDIT: CIRCULATION
Exposure to extremely hot or cold temperatures increases a heart disease patient’s risk of dying, according to a new study published today in the American Heart Association’s journal Circulation. The global analysis of more than 32 million cardiovascular deaths over 40 years measured more deaths on days when temperatures were at their highest or lowest compared to more moderate climate days.
“It underscores the urgent need to develop measures that will help our society mitigate the impact of climate change on cardiovascular disease,” said study co-author Haitham Khraishah, MD, a cardiovascular disease fellow at the University of Maryland School of Medicine (UMSOM) and University of Maryland Medical Center (UMMC).
Among the types of cardiovascular disease, people with heart failure were most likely to be negatively impacted by very cold and very hot days, experiencing a 12 percent greater risk of dying on extreme heat days compared to optimal temperature days in a specific city. Extreme cold increased the risk of heart failure deaths by 37 percent.
Findings were based on an analysis of health data from more than 32 million cardiovascular deaths that occurred in 567 cities in 27 countries on 5 continents between 1979 and 2019. The definition of extreme weather differed from city to city. It was defined as the top 1 percent or bottom 1 percent of the “minimum mortality temperature,” which is the temperature at which the lowest death rate is achieved.
For every 1,000 cardiovascular deaths, the researchers found that:
Extreme hot days (above 86° F in Baltimore) accounted for 2.2 additional deaths.
Extreme cold days (below 20° F in Baltimore) accounted for 9.1 additional deaths.
Of the types of heart diseases, the greatest number of additional deaths was found for people with heart failure (2.6 additional deaths on extreme hot days and 12.8 on extreme cold days).
“While we do not know the reason why temperature effects were more pronounced with heart failure patients it could be due to the progressive nature of heart failure as a disease,” said Dr. Khraishah. “One out of four people with heart failure are readmitted to the hospital within 30 days of discharge, and only 20 percent of patients with heart failure survive 10 years after diagnosis.”
Climate change has been found to cause weather extremes on both ends of the spectrum with hotter summers and colder winters. A 2021 study published in the journal Science found that Arctic warming caused a change of events leading to a disruption of the polar vortex causing periods of extreme cold in the Northern hemisphere.
Barrak Alahmad, MD, PhD, research fellow at the Harvard T.H. Chan School of Public Health at Harvard University in Boston and a faculty member at the College of Public Health at Kuwait University in Kuwait City was the corresponding author of the study. Dr. Khraishah and Dr. Alahmad led an effort over the past four years to build the heart disease mortality database for this study with their colleagues from more than 35 institutions worldwide.
The team developed and expanded the heart disease mortality database as part of the Multi-Country Multi-City (MCC) Collaborative Research Network. This is a consortium of epidemiologists, biostatisticians and climate scientists studying the health impacts of climate and related environmental stressors on death rates.
“This study provides an indisputable link between extreme temperatures and heart disease mortality from one of the largest multinational datasets ever assembled,” said Mark T. Gladwin, MD, Dean, UMSOM, Vice President for Medical Affairs, University of Maryland, Baltimore, and the John Z. and Akiko K. Bowers Distinguished Professor. “The data can be more deeply mined to learn more about the role of health disparities and genetic predispositions that make some populations more vulnerable to climate change.”
Such questions will be addressed in future research, according to Dr. Khraishah.
Some limitations of the study include an underrepresentation of data from South Asia, the Middle East and Africa. It could be that extreme heat had more of an impact than initially measured due to this lack of data.
The researchers took into account humidity and air pollutants, which could have accounted for excess deaths in places of temperature extremes. They also controlled for the delayed effect of temperature on human health (lag effect) and climate zone.
“This landmark paper is a call to view climate change as a growing public health concern and highlights the need to investigate it as a potential cause of health disparities,” said Stephen N. Davis, MBBS, Chair of the Department of Medicine at UMSOM and Physician-in-Chief at UMMC.
This analysis was funded by the Kuwait Foundation for the Advancement of Science.
About the University of Maryland School of Medicine
Now in its third century, the University of Maryland School of Medicine was chartered in 1807 as the first public medical school in the United States. It continues today as one of the fastest growing, top-tier biomedical research enterprises in the world -- with 46 academic departments, centers, institutes, and programs, and a faculty of more than 3,000 physicians, scientists, and allied health professionals, including members of the National Academy of Medicine and the National Academy of Sciences, and a distinguished two-time winner of the Albert E. Lasker Award in Medical Research. With an operating budget of more than $1.3 billion, the School of Medicine works closely in partnership with the University of Maryland Medical Center and Medical System to provide research-intensive, academic, and clinically based care for nearly 2 million patients each year. The School of Medicine has nearly $600 million in extramural funding, with most of its academic departments highly ranked among all medical schools in the nation in research funding. As one of the seven professional schools that make up the University of Maryland, Baltimore campus, the School of Medicine has a total population of nearly 9,000 faculty and staff, including 2,500 students, trainees, residents, and fellows. The combined School of Medicine and Medical System (“University of Maryland Medicine”) has an annual budget of over $6 billion and an economic impact of nearly $20 billion on the state and local community. The School of Medicine, which ranks as the 8th highest among public medical schools in research productivity (according to the Association of American Medical Colleges profile) is an innovator in translational medicine, with 606 active patents and 52 start-up companies. In the latest U.S. News & World Report ranking of the Best Medical Schools, published in 2021, the UM School of Medicine is ranked #9 among the 92 public medical schools in the U.S., and in the top 15 percent (#27) of all 192 public and private U.S. medical schools. The School of Medicine works locally, nationally, and globally, with research and treatment facilities in 36 countries around the world. Visit medschool.umaryland.edu
JOURNAL
Circulation
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality
ARTICLE PUBLICATION DATE
12-Dec-2022
Extremely hot and cold days linked to cardiovascular deaths
More heart failure deaths were linked with extreme temperatures than other heart conditions, from an international study in the journal Circulation
Peer-Reviewed PublicationResearch Highlights:
- According to a multinational analysis of more than 32 million cardiovascular deaths over four decades, there were more deaths on days when temperatures were at their highest or lowest.
- Among the types of cardiovascular disease, people with heart failure experienced the most additional deaths when temperatures were at extremes.
- With climate change, more research is needed to examine and develop strategies to potentially mitigate the impact of extreme temperatures on cardiovascular disease, researchers said.
DALLAS, Dec. 12, 2022 — Extremely hot and cold temperatures both increased the risk of death among people with cardiovascular diseases, such as ischemic heart disease (heart problems caused by narrowed heart arteries), stroke, heart failure and arrhythmia, according to new research published today in the American Heart Association’s flagship journal Circulation.
Among the cardiovascular diseases examined in this study, heart failure was linked to the highest excess deaths from extreme hot and cold temperatures.
“The decline in cardiovascular death rates since the 1960s is a huge public health success story as cardiologists identified and addressed individual risk factors such as tobacco, physical inactivity, Type 2 diabetes, high blood pressure and others. The current challenge now is the environment and what climate change might hold for us,” said Barrak Alahmad, M.D., M.P.H., Ph.D., research fellow at the Harvard T.H. Chan School of Public Health at Harvard University in Boston and a faculty member at the College of Public Health at Kuwait University in Kuwait City.
Researchers explored how extreme temperatures may affect heart diseases – the leading cause of death globally. They analyzed health data for more than 32 million cardiovascular deaths that occurred in 567 cities in 27 countries on 5 continents between 1979 and 2019. The global data came from the Multi-Country Multi-City (MCC) Collaborative Research Network, a consortium of epidemiologists, biostatisticians and climate scientists studying the health impacts of climate and related environmental stressors on death rates.
Climate change is associated with substantial swings in extreme hot and cold temperatures, so the researchers examined both in the current study. For this analysis, researchers compared cardiovascular deaths on the hottest and the coldest 2.5% of days for each city with cardiovascular deaths on the days that had optimal temperature (the temperature associated with the least rates of deaths) in the same city.
For every 1,000 cardiovascular deaths, the researchers found that:
- Extreme hot days accounted for 2.2 additional deaths.
- Extreme cold days accounted for 9.1 additional deaths.
- Of the types of heart diseases, the greatest number of additional deaths was found for people with heart failure (2.6 additional deaths on extreme hot days and 12.8 on extreme cold days).
“One in every 100 cardiovascular deaths may be attributed to extreme temperature days, and temperature effects were more pronounced when looking at heart failure deaths,” said Haitham Khraishah, M.D., co-author of the study and a cardiovascular disease fellow at the University of Maryland School of Medicine and the University of Maryland Medical Center in Baltimore. “While we do not know the reason, this may be explained by the progressive nature of heart failure as a disease, rendering patients susceptible to temperature effects. This is an important finding since one out of four people with heart failure are readmitted to the hospital within 30 days of discharge, and only 20% of patients with heart failure survive 10 years after diagnosis.”
Researchers suggest targeted warning systems and advice for vulnerable people may be needed to prevent cardiovascular deaths during temperature extremes.
“We need to be on top of emerging environmental exposures. I call upon the professional cardiology organizations to commission guidelines and scientific statements on the intersection of extreme temperatures and cardiovascular health. In such statements, we may provide more direction to health care professionals, as well as identify clinical data gaps and future priorities for research,” Alahmad said.
The underrepresentation of data from South Asia, the Middle East and Africa limits the ability to apply these findings to make global estimates about the impact of extreme temperatures on cardiovascular deaths.
“This study contributes important information to the ongoing societal discussions regarding the relationship between climate and human health. More work is needed to better define these relationships in a world facing climate changes across the globe in the years ahead, especially as to how those environmental changes might impact the world’s leading cause of death and disability, heart disease,” said AHA Past President Robert A. Harrington, M.D., FAHA, who is the Arthur L. Bloomfield Professor of Medicine and chair of the department of medicine at Stanford University.
Other co-authors of the study are Dominic Royé, Ph.D.; Ana Maria Vicedo-Cabrera, Ph.D.; Yuming Guo, Ph.D.; Stefania I. Papatheodorou, M.D.; Souzana Achilleos, Sc.D.; Fiorella Aquaotta, Ph.D.; Ben Armstrong, Ph.D.; Michelle L. Bell, Ph.D.; Shih-Chun Pan, Ph.D.; Micheline Sousa Zanotti Stagliorio Coelho, Ph.D.; Valentina Colistro, Ph.D.; Tran Ngoc Dang, Ph.D.; Do Van Dung, Ph.D.; Francesca K. De’ Donato, Ph.D.; Alireza Entezari, Ph.D.; Yue-Liang Leon Guo, Ph.D.; Masahiro Hashizume, Ph.D.; Yasushi Honda, Ph.D.; Ene Indermitte, Ph.D.; Carmen Íñiguez, Ph.D.; Jouni J.K. Jaakkola, Ph.D.; Ho Kim, Ph.D.; Eric Lavigne, Ph.D.; Whanhee Lee, Ph.D.; Shanshan Li, Ph.D.; Joana Madureira, Ph.D.; Fatemeh Mayvaneh, Ph.D.; Hans Orru, Ph.D.; Ala Overcenco, Ph.D.; Martina S. Ragettli, Ph.D.; Niilo R. I. Ryti, Ph.D.; Paulo Hilario Nascimento Saldiva, Ph.D.; Noah Scovronick, Ph.D.; Xerxes Seposo, Ph.D.; Francesco Sera, Ph.D.; Susana Pereira Silva, M.Sc.; Massimo Stafoggia, Ph.D.; Aurelio Tobias, Ph.D.; Eric Garshick, M.D.; Aaron S. Bernstein, M.D.; Antonella Zanobetti, Ph.D.; Joel Schwartz, Ph.D.; Antonio Gasparrini, Ph.D.; and Petros Koutrakis, Ph.D. Authors’ disclosures are listed in the manuscript.
This analysis was funded by the Kuwait Foundation for the Advancement of Science (KFAS).
Studies published in the American Heart Association’s scientific journals are peer-reviewed. The statements and conclusions in each manuscript are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are available here.
Additional Resources:
- Multimedia is available on right column of release link https://newsroom.heart.org/news/extremely-hot-and-cold-days-linked-to-cardiovascular-deaths?preview=a5fb2734e505d474197efc8c790d6d9e
- After Dec. 12, view the manuscript online.
- AHA news release: Keep cool to be heart-healthy in extreme heat (June 2022)
- AHA news release: Use these tips for getting healthy – and staying healthy – during the cold Winter months (Jan. 2022)
- AHA news release: 5 ways to keep your heart safe in extreme heat (July 2021)
- Follow AHA/ASA news on Twitter @HeartNews
- Follow news from the AHA’s flagship journal Circulation @CircAHA
About the American Heart Association
The American Heart Association is a relentless force for a world of longer, healthier lives. We are dedicated to ensuring equitable health in all communities. Through collaboration with numerous organizations, and powered by millions of volunteers, we fund innovative research, advocate for the public's health and share lifesaving resources. The Dallas-based organization has been a leading source of health information for nearly a century. Connect with us on heart.org, Facebook, Twitter or by calling 1-800-AHA-USA1.
###
JOURNAL
Circulation
ARTICLE TITLE
Associations Between Extreme Temperatures and Cardiovascular Cause-Specific Mortality: Results From 27 Countries
