Asthma ICU Admissions Fail to Decline Over 10 Years as Children Face Rising Risk

Asthma ICU admissions have not declined over the past decade despite advances in asthma treatment and management. A large population-based study from Ontario, Canada, found that intensive care use remained stable among adults but increased significantly among children, with the youngest patients accounting for a striking share of ICU admissions.

The study analyzed health administrative data covering nearly 2 million Ontario residents aged 0–59 years with prevalent asthma between 2013 and 2022. Among 52,919 people hospitalized for asthma or an asthma-related condition, there were 71,258 admissions, including 7,870 admissions that required intensive care.

The findings are important because they challenge the assumption that improvements in asthma medications and clinical management should automatically translate into fewer severe attacks requiring ICU treatment. Instead, the data suggest that the burden of severe asthma remains substantial and may be changing differently across age groups.

Asthma ICU admissions show a striking age divide

The most significant finding was the divergence between pediatric and adult patients.

Among children aged 0–18 years, asthma ICU admission rates increased from 0.64 per 1,000 prevalent asthma cases in 2013 to 1.67 per 1,000 in 2022. That represents an increase of nearly threefold over the study period.

The increase was particularly pronounced among children aged 0–5 years. More than 30% of all asthma ICU admissions involved children younger than six, making this age group a major focus for clinicians and healthcare planners.

Importantly, the pediatric increase was not simply a consequence of the COVID-19 pandemic. Researchers found that ICU admission rates among children were already rising significantly between 2013 and 2019, before the pandemic began.

Adult asthma ICU admissions remained largely unchanged

The picture among adults was considerably different.

For patients aged 19–59 years, asthma ICU admission rates were 0.33 per 1,000 prevalent asthma cases in 2013 and 0.28 per 1,000 in 2022. Researchers found no significant improvement in adult ICU admission rates or invasive ventilation rates during the prepandemic period.

That stability is notable. Modern asthma care includes inhaled corticosteroids, combination inhalers, biologic therapies for selected patients, asthma action plans and improved approaches to managing exacerbations. Yet the population-level data do not show a corresponding reduction in adult critical-care use.

The findings suggest that treatment advances may be improving outcomes for many patients without eliminating the smaller but clinically important group that continues to experience severe exacerbations.

How many asthma ICU patients required ventilation?

Across the entire ICU population, approximately 27% of admissions required invasive mechanical ventilation.

Among children, researchers observed a trend toward lower invasive ventilation rates over time, although the change was not statistically significant. Pediatric ICU stays lasting more than 10 days also became less common, while shorter stays of one to five days increased.

This creates an important distinction: more pediatric ICU admissions do not necessarily mean that children are experiencing progressively more severe respiratory failure.

Some children may be admitted to intensive care for close monitoring, respiratory support or rapidly changing symptoms without ultimately requiring prolonged invasive ventilation.

Why rising pediatric ICU admissions do not automatically mean worse asthma

One of the most important insights from the study is that ICU admission is not a perfect measure of physiological severity.

The administrative data could not reliably determine why each patient was admitted to intensive care. It also could not adequately measure the use of noninvasive ventilation, an increasingly important form of respiratory support.

If clinicians are using noninvasive ventilation more frequently, or admitting young children earlier for closer monitoring, ICU admission numbers could rise without a corresponding increase in the severity of respiratory failure.

The researchers therefore caution against interpreting the pediatric trend as straightforward evidence that asthma itself has become more dangerous.

Young children present a particular diagnostic challenge

Another factor complicates the findings in children under six: not every respiratory illness recorded under an asthma-related diagnosis necessarily represents classic asthma.

Young children can experience wheezing and breathing difficulties from a variety of viral and respiratory conditions. Distinguishing early childhood asthma from other causes of acute respiratory symptoms can be challenging, particularly in very young patients.

That means some of the increase in ICU admissions may reflect changes in diagnostic coding or the inclusion of other respiratory illnesses alongside asthma-related hospitalizations.

However, this limitation does not eliminate the significance of the trend. Young children clearly represent a substantial proportion of severe respiratory admissions, making them an important group for further investigation.

Which patients were more likely to require intensive care?

The study identified several characteristics associated with ICU-level asthma care.

Patients requiring intensive care were more likely to have obesity, anxiety or depression, rural residence, and previous asthma-related emergency department visits or hospitalizations.

These associations do not prove that any one factor directly causes an ICU admission. Instead, they identify patient characteristics that may help researchers understand why some people repeatedly experience severe asthma despite available treatments.

Previous emergency department visits and hospitalizations are particularly important because they can signal unstable disease or difficulty maintaining asthma control.

Frequent emergency care may be an early warning sign

A history of asthma-related emergency care deserves attention because severe exacerbations rarely occur in complete isolation.

Repeated emergency department visits may indicate inadequate long-term control, difficulty accessing outpatient care, inconsistent medication use, environmental triggers or a more difficult-to-treat form of asthma.

From a healthcare planning perspective, this suggests that preventing ICU admissions may require intervention well before a patient reaches critical care.

Instead of focusing exclusively on ICU treatment, healthcare systems could use repeated emergency visits and hospitalizations as opportunities to reassess diagnosis, inhaler technique, medication adherence, exposure to triggers and access to specialist care.

Asthma ICU stays are becoming more complicated among adults

Although adult ICU admission rates did not significantly increase, another finding deserves attention: long ICU stays became more common before the pandemic.

Between 2013 and 2019, adult ICU stays lasting longer than 10 days increased. By 2022, approximately one-third of adult asthma ICU admissions lasted more than 10 days.

This matters because ICU burden is not measured only by the number of admissions. The length of hospitalization also affects healthcare resources, staffing requirements and overall costs.

A stable admission rate can therefore conceal a substantial burden if individual patients require longer and more resource-intensive care.

What the study says about mortality

Despite changes in ICU admission patterns, in-hospital mortality did not change significantly over the study period.

This is an important piece of context. The rising number of pediatric ICU admissions should not be interpreted as evidence that asthma deaths are necessarily increasing.

Instead, the data suggest a more nuanced situation: more children are reaching intensive care, but several measures of severe physiological deterioration did not show a corresponding worsening trend.

For adults, the persistence of ICU admissions without significant improvement highlights a different challenge — reducing the number of severe exacerbations that progress to critical illness.

Why asthma treatment advances have not eliminated ICU admissions

Asthma management has changed substantially over the past decade, but treatment effectiveness at the individual level does not necessarily translate into declining ICU admissions across an entire population.

Asthma is highly variable. Patients differ in disease severity, inflammatory pathways, triggers, medication response and adherence. Some patients also have multiple conditions that complicate respiratory management.

Modern therapies can substantially reduce exacerbations for appropriate patients, but access to specialist treatment, correct diagnosis, consistent medication use and early intervention remain essential.

There is also a difference between having effective asthma treatments available and ensuring that every high-risk patient receives the right treatment consistently.

Comparison: children versus adults

The pandemic explains only part of the story

The study period includes the COVID-19 pandemic, which dramatically changed respiratory healthcare, hospital admissions and exposure to respiratory viruses.

However, the pediatric findings cannot simply be dismissed as a pandemic effect. Researchers found that pediatric ICU admission rates were already increasing significantly during the prepandemic years from 2013 through 2019.

This is one of the study’s most important strengths because it shows that the underlying trend predates the disruption caused by COVID-19.

What healthcare systems should take from the findings

The results suggest that asthma surveillance should become more age-specific rather than relying on a single overall measure of disease burden.

For children, particularly those younger than six, healthcare systems need better understanding of why severe respiratory admissions are increasing and whether changes in diagnosis, admission practices, viral infections or asthma control are driving the trend.

For adults, the priority may be different: identifying patients at risk of prolonged ICU stays and preventing severe exacerbations before they require critical care.

Rural populations may also require particular attention because geographic barriers can affect access to specialists, emergency services and long-term asthma management.

What the study cannot tell us

The research provides valuable population-level evidence, but it has important limitations.

Because the investigators relied on administrative health data, they could not determine the precise clinical reason for every ICU admission. The dataset also could not reliably capture noninvasive ventilation, limiting the ability to assess changes in respiratory support practices.

Asthma-related diagnostic codes may also include other respiratory conditions, particularly among very young children.

Finally, the study was conducted in Ontario. Differences in healthcare systems, asthma treatment access, population characteristics and clinical practice mean that the findings cannot automatically be applied to every country.

The bigger insight: ICU admissions are only the visible part of the problem

The most useful way to interpret the findings may be to look beyond the ICU itself.

An ICU admission is often the final stage of a longer pathway involving symptoms, worsening asthma control, emergency care and hospital admission. If healthcare systems focus only on intensive care, they may miss opportunities to intervene earlier.

The combination of previous emergency visits, hospitalizations and other patient characteristics identified in the study could potentially help clinicians identify people who need more intensive preventive management.

The rising pediatric ICU rate also suggests that simply measuring asthma prevalence is not enough. Healthcare planners need to monitor how asthma behaves across different age groups and how frequently patients progress from routine care to emergency and intensive care.

What could happen next?

Future research will need to determine whether the increase in pediatric ICU admissions reflects changing asthma prevalence, respiratory infections, diagnostic practices, ICU admission thresholds, environmental exposures, treatment access or a combination of these factors.

Researchers will also need better clinical data to distinguish true asthma exacerbations from other causes of acute respiratory distress in very young children.

For adults, further investigation into prolonged ICU stays could help identify patients who require more aggressive prevention strategies before severe exacerbations occur.

Conclusion

Asthma ICU admissions have not declined over the past decade, and the burden is increasingly divided by age. Ontario’s population-based study found that adult ICU admission rates remained relatively stable, while pediatric admissions increased substantially, particularly among children younger than six.

The findings do not prove that asthma attacks are becoming universally more severe. Lower or stable measures of invasive ventilation and ICU length of stay among children suggest that changes in admission practices, respiratory support or diagnosis may also be contributing.

Nevertheless, the trend deserves attention. More than 30% of asthma ICU admissions involved children under six, while adults continued to experience a persistent burden of critical illness and increasingly prolonged ICU stays.

The broader lesson is clear: advances in asthma treatment have not eliminated the need for critical care. The next challenge is identifying high-risk patients earlier, improving long-term disease control and understanding why young children in particular are increasingly reaching the ICU.

Reference: McCoy J et al. Trends in intensive care unit admissions in patients with asthma: A 10-year population-based study. Ann Am Thorac Soc. 2026. doi:10.1093/annalsats/aaoag247.