Patient demographics, chronic asthma factors, acute asthma presentation and emergency department (ED) course for asthma exacerbation, according to the number of ED visits in the 1-year period
| 1 ED visit | 2 ED visits | ≥3 ED visits | ||
|---|---|---|---|---|
| Variables* | (n=784) | (n=117) | (n=101) | p Value |
| Age (years), median (IQR) | 34 (26–43) | 34 (25–42) | 37 (27–43) | 0.45 |
| Male sex | 43 (40–47) | 41 (32–50) | 39 (29–49) | 0.64 |
| Current smoker | 42 (39–46) | 32 (24–42) | 49 (38–59) | 0.045 |
| Chronic asthma factors | ||||
| History of oral corticosteroid use for asthma | 35 (31–40) | 75 (64–84) | 84 (75–91) | <0.001 |
| History of hospital admission for asthma | 23 (20–27) | 50 (39–61) | 66 (55–75) | <0.001 |
| History of intubation for asthma | 1 (1–3) | 1 (0–7) | 8 (3–16) | <0.001 |
| History of hospital admission for asthma in the past year | 2 (1–3) | 19 (12–28) | 34 (25–45) | <0.001 |
| Current use of inhaled corticosteroids | 23 (20–26) | 45 (36–55) | 63 (53–72) | <0.001 |
| Current use of oral xanthines | 10 (8–12) | 12 (7–20) | 26 (18–36) | <0.001 |
| Current use of leukotriene modifiers | 8 (6–10) | 16 (10–25) | 29 (21–39) | <0.001 |
| Acute asthma presentation | ||||
| Duration of symptoms | ||||
| <4 h before ED arrival | 16 (14–19) | 13 (7–20) | 21 (13–31) | 0.08 |
| 4–23 h | 43 (40–47) | 49 (39–58) | 53 (42–63) | |
| 1–7 days | 34 (31–38) | 36 (27–46) | 22 (14–32) | |
| >7 days | 7 (5–9) | 3 (1–8) | 4 (1–10) | |
| ED course | ||||
| Initial respiratory rate (breath/min), mean (SD) | 22±6 | 21±6 | 24±6 | 0.07 |
| Initial oxygen saturation (%), mean (SD) | 95±3 | 95±4 | 95±4 | 0.12 |
| Initial peak flow† (L/min), mean (SD) | 214±103 | 254±63 | 170±57 | 0.21 |
| Number of inhaled β-agonists in first hour, median (IQR) | 1 (1–2) | 1 (1–2) | 1 (1–2) | 0.33 |
| Number of inhaled β-agonists over ED stay, median (IQR) | 1 (1–2) | 1 (1–2) | 2 (1–2) | 0.17 |
| Received systemic corticosteroid treatment | 41 (37–44) | 44 (34–53) | 62 (52–72) | <0.001 |
| ED disposition | 0.62 | |||
| Sent home | 89 (86–91) | 86 (79–92) | 89 (81–94) | |
| Hospital admission | 11 (9–13) | 12 (7–19) | 11 (6–19) | |
| Other (eg, left against medical advice) | 1 (0–1) | 2 (0–6) | 0 | |
| Sent home with systemic corticosteroids | 35 (32–39) | 29 (20–39) | 32 (23–43) | 0.42 |
*Data were expressed as % (95% CI) unless otherwise specified.
†Analysed for 56 patients (6%) with initial peak flow available.