Time of admission (year) 2018 2019 2020 2021 Total Peak 2021 †
Number of general PICU admissions (n) 681 708 666 735 2790 270
Number of admissions for SAA (n) 32 41 36 59 168 38
Relative percentage of PICU admissions for SAA (%) 4.7% 5.8% 5.4% 8.0% 6.0% 14.1%
Demographics of the study population Demographics of the study population Demographics of the study population Demographics of the study population Demographics of the study population Demographics of the study population Demographics of the study population
Girls (n (%)) 8 (25%) 16 (39%) 14 (38.9%) 27 (45.8%) 65 (38.7%) 18 (47.4%)
Age in years (mean (SD)) 7.0 (3.6) 7.1 (3.7) 7.9 (3.6) 7.4 (3.6) 7.4 (3.6) 7.0 (3.5)
Divorced parents (n (%)) 12 (37.5%) 12 (29.3%) 8 (22.2%) 17 (28.8%) 49 (29.2%) 12 (31.6%)
Living with a single parent (n (%)) 8 (25%) 8 (19.5%) 1 (2.8%) 8 (13.6%) 25 (14.9%) 4 (10.5%)
Clinical characteristics of the study population Clinical characteristics of the study population Clinical characteristics of the study population Clinical characteristics of the study population Clinical characteristics of the study population Clinical characteristics of the study population Clinical characteristics of the study population
Clinical diagnosis of viral infection ‡ (n (%)) 28 (87.5%) 22 (53.7%) 25 (69.4%) 43 (72.9%) 118 (70.2%) 29 (76.3%)
Conducting virology laboratory tests § (n (%)) 12 (37.5%) 18 (43.9%) 30 (83.3%) 41 (62.5%) 101 (60.1%) 24 (63.2%)
Allergy history (n (%)) 18 (56.3%) 19 (46.3%) 19 (52.8%) 31 (52.5%) 90 (53.6%) 18 (47.4%)
Previously diagnosed with asthma (n (%)) 19 (59.4%) 21 (51.2%) 15 (41.7%) 21 (35.6%) 76 (45.2%) 13 (34.2%)
Days between symptom onset and admission (median (25th-75th percentiles)) 3 (1-7) 2 (1-3.4) 2 (1-4) 3 (2-6.3) 2 (1-5) 2.5 (2-5)
Duration of hospitalization in days (median (25th-75th percentiles)) 2 (2-3) 2 (1-3.5) 2 (2-3) 2 (2-3) 2 (1-3) 2 (2-3.3)
Environmental factors Environmental factors Environmental factors Environmental factors Environmental factors Environmental factors Environmental factors
Ambient PM2.5 concentration (micrograms per cubic meter of air) (median (25th-75th percentiles)) 10.4 (6.5-17.5) 7.4 (4.4-12.63) 7.6 (4.7-11.7) 9.5 (6.4-13.8) 8.6 (5.5-13.9) 9.9 (6.9-14)
Pollen (grains per cubic meter of air) (median (25th-75th percentiles)) 7 (1-28) 14.5 (2-60.7) 7 (1-22) 4 (1-25.7) 7 (1-30.5) 1 (1-8.5)
Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses) Abbreviations: PM2.5 = fine particulate matter; SAA = severe acute asthma Footnotes: † Peak 2021 was the time period from August to November 2021 ‡ As per physician diagnosis. § There were two types of viral test kit used; a simple one (Influenza A and B, SARS-CoV-2 and RSV) and a complete one (consisting of twelve respiratory viruses)