2022 International Consensus on Cardiopulmonary Resuscitation ...
Fixing Air Pollution Could Dramatically Improve Health Disparities
Dolores Perales was 10 years old the first time she couldn't take a breath and thought she was going to die. Parts of the memory remain vague: she knows it was early April, the start of softball season, and she was playing outside. What she remembers clearly is the tightness in her chest and the rising panic. After it happened repeatedly, her mother took her to a doctor, who diagnosed her with asthma. "Ever since then I just had my inhaler," she says. "One of my younger brothers had asthma; my cousin across the street had asthma. So many of the kids in my classroom had asthma," Perales says. "As a kid, you kind of start thinking this is something normal."
Equally normal, as far as Perales was concerned, was a Detroit skyline hazed by the fume-spewing Marathon petroleum refinery. And the Ambassador Bridge—the busiest vehicle crossing between the U.S. And Canada, often packed with idling, diesel-fueled trucks—was typical, too. Both were within a few miles of her home.
It was not until Perales began traveling with her middle school softball, volleyball and basketball teams that she realized the chemical-laced air she knew so well was not the norm for everyone. Just a 30-minute drive from her own neighborhood, Perales encountered quiet, tree-lined streets. But even more striking to her than the greenery was the suburban air. "It smelled different," she says. "When I was out there, it didn't smell bad."
Nearly a decade after that first asthma attack, Perales began attending college at Michigan State University, where the air was so pristine that she rarely needed her inhaler. A few years later, during graduate courses in environmental justice, Perales learned that the emissions in the air that made her so sick were a direct result of discrimination—the refinery and the bridge had been placed where they were because, years before, her community had been deemed less important than the well-to-do suburbs and had neither the means nor the political influence to fight back. Air pollution had become concentrated in her neighborhood as one of the side effects of a discriminatory housing practice known as redlining.
Even when a nation's overall air quality is safe, pockets of polluted air may persist—often in areas where marginalized communities live and work. In the U.S., redlining and practices such as building freeways through poorer neighborhoods have exposed some people to much higher levels of pollution than those in adjacent neighborhoods.
"The major sources of emissions of harmful pollutants are often placed, in unfair ways, in communities that are disadvantaged as a result of discriminatory or racist practices or policies," says environmental health researcher Rima Habre of the University of Southern California.
In countries around the world the burden of poor air quality—and its accompanying health threats—typically falls on lower-income communities, including immigrants, migrant workers and people from other marginalized groups. Any improvements in air quality tend to start in richer neighborhoods. On a global scale, people in high-income countries breathe cleaner air than those in low- and middle-income countries.
Improving air quality is one of the biggest opportunities the world has to save lives and reduce health inequities. In one 2011 estimate, the Environmental Protection Agency predicted that the Clean Air Act would prevent about 230,000 early deaths in 2020 alone. Another U.S.-based study, this one from 2022, estimated that reducing pollution from energy production could save an additional 50,000 lives every year. Such policies could go even further if health equity is factored into policymaking, experts say.
Over the past few decades efforts to learn more about air-pollution risks have led to a greater understanding of the inequity of exposure and how it contributes to health disparities. As Susan Anenberg, an environmental health expert at the George Washington University, says, "We can now get down to a pretty granular scale when thinking about who receives the health benefits of improved air quality and who is still having to deal with the repercussions of poor air quality."
Downwind ThreatsIn the 19th century smoke from inefficient coal fires became one of the first signs of increasing wealth as cities and industries expanded. Coal and petroleum products remain among the primary sources of air pollution around the world. In other words, economic growth still taints the air.
In some places, smoke was considered an aesthetic problem but not necessarily a medical one. Most people were "only concerned with that which was visible," says historian Awadhendra Sharan of the Center for the Study of Developing Societies in Delhi, India. "There's this long-standing view that there is something aesthetically wrong with a polluted atmosphere."
In the U.S., efforts to protect more privileged communities from ugly emissions pushed the dirty air into neighborhoods like Perales's in southwestern Detroit, which were home to immigrant, Black and Hispanic families. The infrastructure needed to support the city, such as the Marathon petroleum plant and the Ambassador Bridge, had to be placed somewhere, "and that somewhere was here," Perales says. "This was an area that was considered undesirable."
It's only in the past 75 years—after events such as the deadly 1948 smog in Donora, Pa., and London's Great Smog, which killed 4,000 people in 1952—that more researchers, physicians and activists began to recognize the health risks of dirty air.
Credit: Miriam Quick and Jen Christiansen; Source: Institute for Health Metrics Evaluation. Used with permission. All rights reserved (data)Air pollution endangers almost every aspect of human health. The worst threat comes from tiny particles, known as PM2.5, that are 2.5 microns or less in diameter. Once inhaled, they can cause or exacerbate respiratory diseases such as asthma, chronic obstructive pulmonary disease and lung cancer. These minute particles slip through layers of lung tissue to enter blood vessels and affect major organs such as the heart, kidneys and liver. They cause inflammation that touches every part of the body, including the brain, and have been linked to heart disease, neurodegenerative illnesses and even dementia. "It seems as though pretty much every organ system can be affected by pollution," says environmental health researcher Michael Brauer of the University of British Columbia and the University of Washington.
People who feel the health impacts most keenly are those who live or work near sources of pollution, such as oil refineries, coal-burning power plants or freeways with smoke-spewing trucks. Numbers can swing wildly from day to day, but PM2.5 levels can get six to eight times higher in pollution hotspots than in neighboring areas. "Many of those very local hotspots of air pollution are inequitably distributed, in the U.S. Especially, on the basis of race and socioeconomic status," Brauer says.
Globally, the degree of risk from deadly air correlates with a person's income and social class. The pattern can be seen at every scale, whether looking at the difference in wealth across nations, neighborhoods within a city or neighbors in a small town. When Brauer was conducting studies of air quality in villages across Mexico and India, he could tell which families were most likely to breathe more dangerous air based solely on signs of poverty.
"We see this pattern across the world, and you can even see it within a single village," Brauer says. He has noticed that poorer families tend to live crowded together in one-room homes. And when the same space is used for cooking, living and sleeping, the entire family is exposed to cookstove fumes. Cookstove fuel differs across classes, too. Poorer families burn crop waste or freshly gathered wood, both of which create more smoke than the dry wood used by wealthier families. In cities, Brauer says, richer people live in homes set back from busy roads, whereas those with fewer means are more likely to live near factories and highways.
Another pattern that researchers see over and over again is that those breathing more toxic air are also those who are most likely to experience societal stressors: poverty, racism, limited health-care access, and more. The combination increases their risk of disease. Researchers are only now beginning to tease apart how the chronic stress of discrimination makes someone more vulnerable to the harms of environmental pollutants. "Social factors cause repeated chronic stress to the point that the body has a harder time defending itself against harmful exposures," Habre says. People who experience social discrimination, especially based on race or ethnicity, are "getting higher exposures, but they are also more susceptible to their harmful effects."
Seeking SolutionsAccording to a 2022 Lancet study, air pollution caused about 6.7 million premature deaths in 2019, mostly in low- and middle-income countries. The nation with the highest number of these deaths was India. As part of its efforts to address this threat, in 2015 the Indian government issued a report that declared air pollution a national health concern. The report laid out a plan to start improving the nation's air, one of the first of its kind from a low- and middle-income country that, Sharan says, clearly states "it is exposure to emissions that matters, and therefore the people who are exposed to it that matter. Once you do that," he says, "then the question of equity comes up."
Creating policies that protect and prioritize the health of the most vulnerable is far from easy. In New Delhi, for instance, air quality is especially awful during certain winter months because of local weather conditions and emissions from agricultural burning as farmers clear fields for planting. To try to protect people's health, government authorities identified a set of steps they hoped would reduce toxic air exposure in the nation's capital. When PM2.5 levels hit a certain mark, schools are to shut down so children can stay indoors. Vehicles must drive only on paved roads so as not to throw excess dust into the air. Private construction activities—at homes, malls, and other nonessential sites—must halt to protect workers and reduce the amount of fine particles flying into the air from cement grinding or stone cutting.
These steps can temporarily lower local PM2.5 levels. But the cost of this reduced activity is most keenly felt by laborers who are paid daily wages. When schools are closed, children in poorer families are more likely to spend time outdoors than to remain inside next to an air purifier.
The people who can't afford to pay attention to the health risks of PM2.5 are typically those most at risk. Thus, when a policy to reduce exposure to pollution threatens someone's income—or a country's economic development, for that matter—it's likely to fail.
Policies that work in rich countries can prove challenging to implement in low- and middle-income nations. Pallavi Pant, a global health researcher at the Health Effects Institute in Boston, points to car emissions as one example. In Kenya and Uganda, the demand for personal vehicles has led to an increase in imported used cars from countries such as Japan. These imported cars were designed to meet emissions-control standards for high-income countries, so they're built using the newest catalytic converters and other pricey pollution-reducing technology. But maintaining those cars, especially locating and paying for parts, can prove difficult in poorer countries. As a result, importers have taken to removing these components altogether before the cars are resold.
But top-down approaches may still be effective, Pant says. In India, for instance, regulators have begun to enforce more stringent standards for vehicle emissions, an approach shown to motivate the auto industry to find ways to meet those standards so it can continue selling cars. The results from this strategy are not yet visible, Pant says, because it takes time for an older fleet of vehicles to be replaced by new, cleaner ones. "We'll continue to see improvements in the vehicle fleet," she says.
Credit: Miriam Quick and Jen Christiansen; Source: Institute for Health Metrics Evaluation. Used with permission. All rights reserved (data)The Indian government has also implemented the National Clean Air Program, a 2019 initiative that tasks state and municipal authorities with especially dirty air to find solutions to their pollution problems. The effort empowered local governments to begin acting on their own air pollution—perhaps most important by making funds available to implement solutions. "That has been a pretty pivotal shift," Pant says. "There's a lot more still to do, but it's a very useful first step in getting people involved."
By themselves, policies and laws cannot tackle the many ways that pollution from high-income countries is exported to low- and middle-income countries, Brauer says. Morals matter, too. He and his colleagues have quantified how outsourcing the production of consumer goods and services from the U.S. To Asia also outsourced the pollutants created by those factories. They estimated that, for the year 2007, about 22 percent of the 3.45 million deaths attributable to air pollution were a result of this reassigned burden of pollution. Although the data are now 15 years old, they still point to an important message. People should be "aware that some of what we are benefiting from has just been transferred to other people," Brauer says.
Progress without PollutionIn wealthy countries, air quality has been improved in part by new, expensive technologies that reduce pollutants but still rely on petroleum and other fossil fuels. Over the long term, however, such a strategy cannot fix the entire problem, because it does not minimize greenhouse gases, which also harm human health and are accelerating the climate crisis, Anenberg says. "We need to be simultaneously reducing greenhouse gases and air pollutants. And the way we do that is by burning less fuel, not putting on these technological control measures."
For decades industrial growth and the amount of pollutants in the air rose and fell together, Brauer says. Although pollution typically settles on the poorest, one exception is in countries with little industrialization, which still have relatively clean air. But as they industrialize and increase their reliance on fossil fuels, their air quality begins to worsen. "We've gone through this in high-income countries," Brauer says. "But many low- and middle-income countries are still in the earlier phases of this arc of industrial development."
Recognizing this problem has prompted some low- and middle-income countries to make changes. Rwanda, for example, has focused on off-grid solar-powered systems to provide electricity to rural areas. As of 2021, nearly 50 percent of the country had access to electricity, with much of that a result of solar power. India, too, is working to increase the amount of electricity it gets from renewable sources. In May the Indian government announced plans to pause proposals for new coal-burning power plants for the next five years and focus instead on renewable energy. "It's not a case that places get worse and worse and never improve," Brauer says. "We really do see improvement."
Such improvements happen when nations prioritize clean air and healthy citizens over short-term profits. Some high-income countries have introduced stringent policies to control pollution that have already led to measurable health improvements. In the U.S., one estimate found that laws controlling vehicle exhaust lowered mortality from traffic-related PM2.5 by 2.4 times between 2008 and 2017. In London, the creation of an ultralow-emission zone in the central part of the city has reduced the amount of sick leave by an estimated 18 percent.
Another way to offset the health effects of pollution and simultaneously clean up some of our environmental mess is through planting trees. Exposure to PM2.5 can significantly reduce blood flow to the brain, which influences stroke risk. But a study tracking more than 9,000 residents in Beijing found that living amid greenery mitigated this potential harm. And other research has shown that plants might also minimize heart disease risk from PM2.5.
Today, armed with cleaner technologies and an awareness of toxic air's deadly effects, there's a chance that less industrialized countries could continue to choose progress without pollution. "This is not an either-or situation," Anenberg says. "We can do both of these at the same time." For clean and healthy air, this may be the only way to achieve true equity.
Trends In Hospital Admissions For Chronic Obstructive Pulmonary Disease Over 16 Years In Canada
AbstractBackground: Chronic obstructive pulmonary disease (COPD) is an ambulatory care–sensitive condition, and the rate of hospital admissions for COPD is an indicator of the quality of outpatient care. We sought to determine long-term trends in hospital admissions for COPD in Canada.
Methods: Using a comprehensive national database of hospital admissions in Canada, we identified those with a main discharge diagnosis of COPD for patients aged 40 years and older between 2002 and 2017. We calculated sex-specific, age-standardized trends in annual rates of hospital admissions for COPD separately for younger (40–64 yr) and older adults (≥ 65 yr). We used spline regression to examine changes in the admissions trends for each sex and age group.
Results: Over 16 years, 1 134 359 hospital admissions were for COPD. Between 2002 and 2017, the total number of admissions increased by 68.8%, from 52 937 to 89 384. The overall crude admission rate increased by 30.0%, from 368 to 479 per 100 000 population, and the sex-and age-standardized admission rate increased by 9.6%, from 437 to 479 per 100 000 population. Age-standardized rates increased by 12.2% among younger females, by 24.4% among younger males and by 29.8% among older females, but decreased by 9.0% among older males. Over the same period, the all-cause sex-and age-standardized admission rate declined by 23.0%.
Interpretation: Hospital admissions for COPD have increased since 2010, even after adjusting for population growth and aging, and despite declining rates of all-cause hospital admissions. The secular increase in COPD admissions indicates that the burden of COPD on Canadian health care systems is increasing.
Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease that imposes a substantial burden on patients and Canadian health care systems. Despite plateauing rates of smoking, the burden of COPD is projected to increase in Canada because of population growth and aging.1–3 As the health care system approaches the upper limit of budget expansion, it is increasingly crucial to identify gaps in care that lead to higher utilization.4 Hospital admissions for COPD may represent one such area for improvement as, in many instances, they could be avoided with proper preventive or early therapeutic interventions.5,6 For this reason, COPD is considered an ambulatory care–sensitive condition, and trends in COPD admissions are interpreted as an indicator of the quality of outpatient care.7 Despite this, COPD remains one of the most common reasons for hospital admission in Canada.8 A Canadian study showed that COPD-specific admissions contribute 57% to the total medical costs of COPD.3
Given population growth and aging, COPD-specific hospital admissions are projected to increase significantly in the future.3 However, population growth and aging contribute to the increasing burden of COPD-specific admissions but do not indicate gaps in care. Secular trends in admissions that account for these factors provide a more informative metric for tracking the quality of outpatient care. Combining secular trends with the projections of population growth and aging enables predictions of the future burden of hospital admissions to inform evidence-based planning.9
We sought to document overall and secular trends in COPD admissions in Canada from 2002 to 2017. We also sought to evaluate trends in general admission rates, lengths of stay, in-hospital mortality and readmission rates among patients with COPD.
Methods Data sourcesWe obtained data from the Hospital Morbidity Database, Canada's national hospital database managed by the Canadian Institute for Health Information (CIHI), which provides complete geographic coverage of all inpatient admissions.10 For each record, we had access to dates of admission and discharge, biological sex, age and discharge diagnoses as coded using the International Classification of Diseases, 9th (ICD-9) or 10th (ICD-10) Revisions. We defined COPD-specific hospital admissions as those with COPD as the primary (most responsible) diagnosis (ICD-9 codes 491, 492, 493.2 and 496, and ICD-10 codes J41–J44). This definition had a sensitivity of 86% and a positive predictive value of 87% in a chart review study.11 To avoid including patients with asthma who might have been incorrectly labelled as having COPD, we excluded patients younger than 40 years at admission.
Statistical analysisWe aggregated COPD admissions annually and stratified them by sex and age group (40–64 yr and ≥ 65 yr). We computed crude and direct sex- and age-standardized rates per 100 000 people using the Census-driven population estimates as the denominator with 1-year age groupings, using the 2017 population as the reference for direct standardization.9 We employed the Byar method for computing 95% confidence intervals (CIs) around rates. By exponentiating the coefficient of the time variable from a negative binomial regression model, we obtained the average annual relative change. To evaluate potentially nonlinear variations in the trends in each sex–age group, we used thin-plate spline regression analysis (9 knots, with the default knot locations determined by the mgcv R package) with the negative binomial model.
We conducted a series of secondary analyses. We further subdivided the younger and older adult groups (40–54 yr, 55–64 yr, 65–74 yr, 75–84 yr, ≥ 85 yr) and used pairwise hypothesis testing with the Bonferroni adjustment to see if the trends were different within each age group. Next, we determined whether trends in COPD-specific hospital admissions paralleled trends in all-cause hospital admissions, reflecting health system–wide factors not specific to COPD. Because all-cause admissions were reported in fiscal years, we recalculated COPD-specific admissions for April–March, inclusive, for this analysis. Further, we tested whether changes in admission rates could be attributed to a threshold effect by evaluating trends in the average length of stay among patients admitted to hospital with COPD and in-hospital mortality in each sex–age group. For example, a temporal trend of admitting less severe cases could result in increased admissions but a shorter average length of stay. A similar threshold phenomenon could exist at the time of discharge; for instance, a trend toward discharging patients earlier may increase the risk of readmissions. To investigate the threshold effect, we evaluated trends in the proportion of patients with no readmissions in the same year and trends in the sex- and age-standardized rate of readmissions within the same year. For this analysis, we excluded the 2% of COPD admissions that had missing anonymized patient identifiers. Lastly, we investigated whether the frequency of the 8 most common comorbidities among patients admitted to hospital for COPD (determined over the entire study period) changed from 2002 to 2017. Discharge diagnostic codes used to classify comorbidities are shown in Appendix 1, Supplementary Table A1, available at www.Cmaj.Ca/lookup/doi/10.1503/cmaj.221051/tab-related-content.
We used R statistical software to conduct all analyses. Unless otherwise stated, all rates are presented per 100 000 population.
Ethics approvalEthics approval was granted by the University of British Columbia's Clinical Research Ethics Board (H18-01026).
ResultsOver the 16-year study period, 1 134 359 admissions were for COPD, of which 240 611 (21.2%) were for younger adults (< 65 yr). The average age at admission was 74 (interquartile range 66–82) years. More than half of admissions were for female patients (n = 127 514, 53.0%) in the younger group and slightly more than half of admissions were for male patients (n = 454 712, 50.9%) in the older group. In the first year of the study (2002), the total number of admissions was 10 381 for the younger group and 42 556 for the older group (Table 1). In the last year of the study (2017), the corresponding numbers were 19 061 and 70 323, representing a relative increase in admissions of 83.6% and 65.3%, respectively. More detailed results are presented in Appendix 1, Supplementary Table A2.
Table 1:Annual number and crude rate per 100 000 population of COPD hospital admissions by calendar year, overall and within sex and age subgroups
Trends in ratesTrends in crude and sex- and age-standardized admissions rates (per 100 000 population) between 2002 and 2017 are depicted in Figure 1. The overall crude rate increased from 368 (95% CI 365 to 372) in 2002 to 479 (95% CI 476 to 482) in 2017. The overall sex-and age-standardized rate of hospital admissions per 100 000 population increased from 437 (95% CI 434 to 440) in the first year to 479 (95% CI 476 to 482) in the last year of the study.
Figure 1:Annual number and crude and sex- and age-standardized rates per 100 000 population of hospital admissions for chronic obstructive pulmonary disease (COPD), by calendar year. Note: CI = confidence interval.
Age-standardized rates increased over the study period in all sex and age groups except older males, among whom the rate was 1341 (95% CI 1324 to 1359) in 2002 and 1220 (95% CI 1207 to 1233) in 2017 (Figure 2). For the younger group, the age-standardized rate of COPD admissions increased from 139 (95% CI 135 to 143) among females and 119 (95% CI 115 to 122) among males in 2002, to 156 (95% CI 153 to 159) among females and 148 (95% CI 145 to 151) among males in 2017. For both males and females in the younger group, the rates increased from 2002 to 2005, subsequently decreased at a modest pace until 2010, and rose again. These patterns were similar to those observed among older females (835, 95% CI 823 to 847, in 2002 to 1084, 95% CI 1073 to 1096, in 2017). However, among older males, the rate nearly plateaued from 2011 to 2014 and declined afterward.
Figure 2:Spline regressions for age-standardized rates per 100 000 population of hospital admissions for chronic obstructive pulmonary disease (COPD), by calendar year, among (A) younger adults aged 40–64 years and (B) older adults aged 65 years and older. Note that scales for the y-axis are different for each age group. Note: CI = confidence interval.
Secondary analysesBy age subgroup, the model-based average annual relative changes in the sex- and age-standardized rate of COPD hospital admissions were 2.4% per year (95% CI 1.7% to 3.1%) for patients aged 40–54 years, 0.7% per year (95% CI 0.3% to 1.2%) for those aged 55–64 years, −0.9% per year (95% CI −1.3% to −0.5%) for those aged 65–74 years, −0.0% per year (95% CI −0.5% to 0.5%) for those aged 75–84 years and 1.3% per year (95% CI 0.6% to 2.0%) for those aged 85 years and older. Most differences between age subgroups were statistically significant (Appendix 1, Supplementary Figure A1).
Sex- and age-standardized rates of all-cause admissions decreased by a model-based relative annual average of −0.8% per year from the baseline rate (95% CI −1.1% to −0.5%) between 2002 and 2016 in fiscal years (corresponding to a relative decline of 23.0% over the study period). In contrast, sex- and age-standardized admission rates for COPD increased by a model-based relative annual average of 1.3% per year (95% CI 0.6% to 1.9%), corresponding to a relative increase of 9.2% over the same period in fiscal years (Figure 3).
Figure 3:Sex-and age-standardized rates of hospital admissions for chronic obstructive pulmonary disease (COPD) per 100 000 population and all-cause hospital admissions per 5000 population per fiscal year. Note: CI = confidence interval.
In-hospital mortality from COPD admission declined in each sex and age group over the study period. The relative change in in-hospital deaths between 2002 and 2017 was −8.3% (from a rate of 2.4 to 2.2 per 100 COPD admissions) for younger females, −7.4% (from 2.7 to 2.5 per 100 COPD admissions) for younger males, −6.3% (from 6.8 to 6.4 per 100 COPD admissions) for older females, and −9.9% (from 8.1 to 7.3 per 100 COPD admissions) for older males (Figure 4). In-hospital mortality was higher among males in both age groups. Among younger adults, in-hospital mortality stayed nearly constant or increased for the first 5 years of the study period and then declined after 2007. Among older adults, in-hospital mortality increased until 2007 and then declined until the end of the study period.
Figure 4:In-hospital mortality per 100 hospital admissions for chronic obstructive pulmonary disease (COPD) by calendar year, among (A) younger adults aged 40–64 years and (B) older adults aged 65 years and older. Note that scales for the y-axis are different by age group. Solid lines indicate the curves fitted by spline regression, and points indicate the observed values. Note: CI = confidence interval.
The average age-standardized length of stay for COPD-specific hospital admissions declined for all sex and age groups from 2002 to 2017. Lengths of stay declined by 20.3% (7.9 d to 6.3 d) among younger females, 16.2% (7.4 d to 6.2 d) among younger males, 16.7% (10.2 d to 8.5 d) among older females and 14.9% (9.4 d to 8.0 d) among older males (Appendix 1, Supplementary Figure A2). The proportion of patients with no readmissions for COPD within the same calendar year remained relatively constant at 78.0% (Appendix 1, Supplementary Table A3). However, the sex-and age-standardized rate of readmissions increased by 15.4% (from 181 to 209 per 100 000 population) over the study period (Appendix 1, Supplementary Figure A3). Of the 8 most common comorbidities among patients admitted to hospital for COPD, 5 increased in proportion from 2002 to 2017, with relative changes of 660.7% (from 0.6% to 4.2%) for acute kidney failure, 166.1% (from 0.8% to 2.1%) for bronchopneumonia, 57.7% (from 10.7% to 16.9%) for pneumonia, 42.2% (from 3.8% to 5.4%) for other lung diseases and 41.8% (from 3.9% to 5.5%) for fluid-, electrolyte- and acid-based disorders. In contrast, the proportion decreased by 79.8% (from 4.4% to 0.9%) for cardiac dysrhythmias, 44.4% (from 5.0% to 2.8%) for diabetes mellitus and 23.3% (from 8.7% to 6.7%) for heart failure (Appendix 1, Supplementary Figure A4).
InterpretationOur study used quality-controlled national population-based data from Canada with complete coverage of inpatient hospital admissions to report trends in admissions for COPD from 2002 to 2017. We have created a Web app that allows rates of COPD-specific hospital admissions to be explored by province and territory (https://resp.Core.Ubc.Ca/ipress/copdHospitalizationCanada).
Considering the number of admissions, the crude rates and the sex- and age-standardized rates together shows interesting patterns. Over 16 years, the number of COPD admissions increased by more than two-thirds, the crude admission rate increased by around 30% and the sex- and age-standardized rate increased by around 10%. The attenuation of trends in admissions from frequencies to crude rates demonstrates the influence of population growth; further attenuation between crude and age-standardized rates reflects the impact of population aging. However, after adjusting for these factors, we still observed a secular increase that cannot be attributed to population demographics. Importantly, sex- and age-standardized rates of COPD admissions increased in excess of sex- and age-standardized rates of all-cause admissions over the same period, which rejects the hypothesis that our observations were driven by rising admissions across all disease areas, and despite the continual reduction in smoking rates in Canada.12 Our findings may indicate an increasing gap in care for COPD compared with other conditions. Alternatively, higher survival rates among patients admitted with severe exacerbations of COPD could result in repeat admissions for such patients. This hypothesis may be supported by the observed decline in lengths of stay and in-hospital mortality. However, the observed increase in the rate of readmissions within the same year could reflect premature discharge of patients with COPD rather than better in-hospital care.13
We observed the secular increase in COPD admissions after adjustment for population growth and aging in all demographic groups except males aged 65 years and older. Similarly, Orozco-Beltran and colleagues14 determined that age-standardized rates of admission for COPD in Spain decreased from 1998 to 2010 among both males and females but started rising, modestly among males and sharply among females until 2018, especially among patients aged 85 years and older. A similar study in Germany reported increasing rates of COPD-specific admissions (2005–2011), with males aged 75–84 years having the highest age-standardized rate of 39.4 hospital admissions per 100 000 population, and females having the greatest average annual increases.15 Improved survival among patients with COPD could increase the prevalence of severe disease and ultimately increase the rate of hospital admissions. Changes in the rates of pneumonia and influenza, the most common causes of COPD exacerbations, could also be contributing to increased admission rates for COPD.16 The mortality rate for influenza and pneumonia has increased since 2010 in Canada, which is in line with the secular increase in COPD admissions after 2010 observed in our study, and with the increased prevalence of pneumonia at admission.17 In addition, the number of comorbid conditions among patients with COPD is increasing, which is associated with a greater risk of hospital admission.18
Many other factors may have influenced the observed trends in admissions. Evidence-based clinical practice and treatment of COPD have undergone major changes over the study period, including the introduction of therapeutic recommendations based on the Global Initiative for Chronic Obstructive Lung Disease severity grades in 2001.19 Decreasing hospital admissions for COPD in other countries has been attributed to this new paradigm of COPD management.20,21 However, trends in use of medication are often not aligned with evidence-based guidelines, and overuse of inhaled corticosteroids, which increase the risk of pneumonia, has been documented among patients with COPD.22 We observed an increase in sex- and age-adjusted rates of COPD admission, particularly after 2010, which was concomitant with an observed decrease in length of stay and in-hospital mortality, and a slight increase in readmissions. These findings may be attributed to a decrease in the threshold for severity of COPD exacerbation leading to admission, better in-hospital management of exacerbations or a combination of both.
Historically, COPD has been regarded as a condition that mainly affects male smokers. Several recent studies have questioned this narrative by documenting the growing burden of COPD among females and nonsmokers.23–25 We observed a sharper increase in rates of hospital admission among older females, compared with all other groups. This may be owing to differences in the prevalence of smoking.26 The observed gap between males and females can be explained by historical trends in smoking prevalence in Canada, which peaked later among females (1974) than among males (1965).27 The burden of hospital admissions for COPD can be expected to follow a similar pattern with a delay. The lagged effect of smoking may explain the declining rates of COPD among older males and continued increase in rates among older females. Sex and gender differences in COPD diagnosis and treatment in clinical practice may also explain these observations.28–30 The role of extrinsic factors such as changes in population exposure to air pollution or indoor toxic inhalants should also be considered.31,32
LimitationsAlthough our study was affected by the adaptation of ICD-10 from ICD-9 that occurred at different time points from 2001 to 2006, its effect on our measurement of admissions was likely negligible as the implementation of ICD-10 did not substantially change coding practices across Canada.33 Similarly, hospital admissions are less sensitive to changes in diagnostic criteria than other measures of COPD burden, including physician visits and prescription records.34 We were unable to assess trends in patient characteristics — such as race, socioeconomic status and smoking status — and their impact on the risk of admission, as these data were unavailable. In addition, we were unable to evaluate trends in COPD admissions for more recent years as a result of lags in data availability because of quality assurance procedures, and a recent change in the content of the data sets that CIHI provides for research, which would affect our ability to compare the results with more recent trends.35
ConclusionThe number of hospital admissions for COPD has rapidly increased since 2010 in Canada. Even after adjusting for population growth and aging, COPD admission rates have risen since 2010 in all groups except among older males. This is in contrast to declining all-cause admission rates over this period. Our findings call into question whether progress is being made in improving COPD care and outcomes.
FootnotesCompeting interests: Don Sin reports honoraria from GSK, Boehringer Ingelheim and AstraZeneca. No other competing interests were declared.
This article has been peer reviewed.
Contributors: Mohsen Sadatsafavi and Larry Lynd contributed to the conception of the study; Joseph Amegadzie, Tae Lee, Mohsen Sadatsafavi and Kate Johnson contributed to the design of the work. Joseph Amegadzie and Tae Lee contributed to data analysis, and all of the authors contributed to interpretation. Joseph Amegadzie and Tae Lee drafted the manuscript. All of the authors revised it critically for important intellectual content, gave final approval of the version to be published and agreed to be accountable for all aspects of the work. Joseph Amegadzie and Tae Yoon Lee are joint first authors.
Funding: This study was funded by a research grant from the Canadian Institutes of Health Research and Genome Canada (274CHI). The funders had no role in any aspect of this study and were not aware of the results.
Data sharing: The aggregated results used in this study are available on the Web app: http://resp.Core.Ubc.Ca/ipress/copdHospitalizationCanada. The individual-level data set was obtained under license from the Canadian Institute for Health Information and cannot be shared.
This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY-NC-ND 4.0) licence, which permits use, distribution and reproduction in any medium, provided that the original publication is properly cited, the use is noncommercial (i.E., research or educational use), and no modifications or adaptations are made. See: https://creativecommons.Org/licenses/by-nc-nd/4.0/
COPD Inhalers' Link To Fracture Risk Supported In Pooled Trials
Chronic obstructive pulmonary disease (COPD) treatments involving inhaled corticosteroids (ICSs) were associated with a greater risk for fractures, a meta-analysis of several dozen randomized trials found.
Use of inhaled ICSs was associated with a 19% increased fracture risk when compared to treatment without ICSs (RR 1.19, 95% CI 1.04-1.37), and that risk held steady when treatment lasted 12 months or more, reported Ruiying Wang, MD, of Shanxi Medical University in China, and coauthors in BMC Pulmonary Medicine.
No increased risk was observed for ICS monotherapy, and the overall link appeared greater when ICS was used in combinations, such as with a long-acting beta-agonist (LABA) or as triple therapy with a LABA plus long-acting muscarinic antagonist (LAMA):
"Currently, it is still controversial that inhaled corticosteroids increase the risk of fracture in patients with COPD. Whether inhaled glucocorticoids increase the risk of fracture in patients with COPD may depend on the timing, dose, and dosage form of the ICSs treatment," Wang and colleagues said.
Subgroup analysis showed that the predictors of fractures were budesonide in high doses via metered-dose inhaler devices, whereas fluticasone furoate and fluticasone propionate in different inhalation devices had no relationship with increased fractures.
The investigators noted that COPD patients tend to be elderly and have various complications, and long-term inhalation of glucocorticoids may increase their risk of fractures.
"The exact mechanisms by which ICSs increase the risk of fracture in COPD patients are unclear. However, due to malnutrition, inflammatory response, and previous exposure to corticosteroids, COPD patients are at risk of fracture porosity and fracture," study authors wrote.
"Long-term and intensive ICS therapy may lead to a small part being absorbed and have systemic effects, resulting in increased bone absorption and decreased bone formation. Moreover, osteoporosis is an important complication of COPD," they added.
Included in the meta-analysis were 44 randomized clinical trials totaling 87,594 patients.
Meeting inclusion criteria were studies that included patients with COPD, treatment interventions including any kind of inhaled glucocorticoids, utilizing non-ICS treatments as a control, and trials that reported fracture events in their results. Observational reports, studies with patients who had asthma or unknown diagnoses, and studies where ICSs were involved in both study cohorts were not included.
Studies were retrieved in October 2022 and were updated in November 2022. Of the 44 trials analyzed, 31 evaluated ICS/LABA therapy compared with control groups (including LAMA only, LABA only, LAMA/LABA, or placebo groups), while 13 evaluated triple therapy in comparison to control groups (including LAMA only, LABA only, LAMA/LABA, or placebo groups). Follow-up periods of the studies ranged from 3 to 36 months.
Factors associated with an increased risk of fracture were average participant age of 65 or above (RR 1.27, 95% CI 1.01-1.61) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III disease (RR 1.18, 95% CI 1.00-1.38).
Limitations to the meta-analysis include lack of fracture classification, possible publication bias as a result of manual retrieval, as well as the heterogeneity in how each randomized trial could report complications and medical histories.
Nevertheless, the pooled data have value as several large-scale randomized controlled trials have already individually failed to link ICSs and fractures directly, and trials tend to exclude people with severe fracture porosity and fractures, authors of the meta-analysis argued.
"Therefore, the impact of ICSs on fracture risk in patients with COPD may be significantly greater in the real-world," Wang and colleagues said.
Elizabeth Short is a staff writer for MedPage Today. She often covers pulmonology and allergy & immunology. Follow
Disclosures
Study authors declared no funding source and no competing interests.
Primary Source
BMC Pulmonary Medicine
Source Reference: Peng S, et al "Effect of fracture risk in inhaled corticosteroids in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis" BMC Pulm Med 2023; DOI: 10.1186/s12890-023-02602-5.
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