While the incidence and prevalence of pediatric asthma decreased from 2008 to 2018 in the United Kingdom (UK), especially among younger age groups, pediatric asthma exacerbations increased, according to study findings published in Thorax.
Researchers reported the incidence and prevalence of pediatric asthma from 2008 to 2018, year-on-year, overall and stratified by age (1-5 years, 6-11 years, and 12-17 years) and sex, based on data from the UK Clinical Practice Research Datalink (CPRD) database. The researchers also assessed wheezing rates among children aged 1 to 5 years and exacerbations rates among children in all age groups.
The analysis included 498,503 children and adolescents (aged 1-17 years), with 190,986 incident cases of asthma identified during the study period. Overall, asthma incidence decreased from 1403.4 (95% CI, 1383.7-1423.2) per 105 person-years (PYs) in 2008 to 688.0 (95% CI 676.3 to 699.9) per 105 PYs in 2018, which was a 51% decrease.
The reduction was most pronounced in participants aged 1 to 5 years, decreasing by 65%: from 2556.9 (95% CI, 2509.8-2604.7) per 105 PYs in 2008 to 892.3 (95% CI, 866.9-918.3) per 105 PYs in 2018. For participants aged 6 to 11 years and 12 to 17 years, the corresponding decreases were 36% (from 1139.9 [95% CI, 1110.6-1169.7] to 739.9 [95% CI, 720.5-759.8]) and 20% (from 572.3 [95% CI, 550.4-594.9] to 459.5 [95% CI, 442.9-476.4]) per 105 PYs, respectively.
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[E]xacerbation rates have increased over our 10-year time span, suggesting that while fewer children are diagnosed with asthma, asthma exacerbations remain an important issue.
The prevalence of asthma declined from 18.0% in 2008 to 10.2% in 2018. The average prevalence change for all participants was 6% per year (odds ratio [OR], 0.94; 95% CI, 0.94-0.94; P <.001), with a higher annual average rate of reduction occurring in those aged 1 to 5 years (10% per year). The incidence and prevalence of asthma were consistently greater among boys vs girls and decreased over time in both sexes.
A total of 102,150 incident cases of preschool wheeze were reported in children aged 1 to 5 years. The overall average preschool wheeze incidence rate change incidence rate ratio (IRR) was 0.98 (95% CI, 0.97-0.99; P = .001), with comparable rates in those aged 1 to 3 years and those aged 4 years.
The overall average preschool wheeze prevalence change OR was 0.98 (95% CI, 0.98-0.99; P <.001), or 2% per year, and was similar in both age groups (ie, ages 1-3 and age 4). Boys had a higher incidence and prevalence of preschool wheeze, which decreased over time for both sexes.
Exacerbation rates increased among all age groups in boys and girls. Children aged 1 to 5 years had the highest exacerbation rate. The overall IRR for linear trend was 1.04 (95% CI, 1.02-1.05; P <.001), suggesting an average increase in exacerbation rate of 4% per year. Similar findings were observed in the different age groups and sexes.
Among several limitations, the study did not assess phenotypes or perform clinical evaluations, such as lung function tests. In addition, the potential effects of variations in diagnostic criteria on asthma prevalence were not considered, and the results should be interpreted in light of advancements in the quality of asthma care.
“The incidence of asthma has decreased over time, particularly in younger age groups, and has been accompanied by a decrease in prevalence,” study authors concluded. However, they also noted that “exacerbation rates have increased over our 10-year time span, suggesting that while fewer children are diagnosed with asthma, asthma exacerbations remain an important issue.”
Disclosure: This study was funded by AstraZeneca. Some of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
