TABLE 3

Retrospectively collected data on asthma exacerbations, hospitalisation and emergency department admissions/visits

Study (year) [ref.]Age range yearsStudy groups nExacerbation parameter(s)Data for exacerbations by specified parameter, for each study group
Exacerbations reported in ≤6 months prior to study entry
 Bateman et al.  (2012) [25]≥1297, 100, 110, 95, 102, 94Pts with ≥1 exacerbation in last 6 months18%, 19%, 16%, 25%, 17%, 21%
 McIvor et al.  (2009) [22]#≥6534Patients with any exacerbation in 6 weeks prior to study entry51.7%
 Skoner et al.  (2005) [57]2–558, 51, 52, 50No. of exacerbations in last 30 daysMean: 1.8, 1.3, 1.5, 1.2 Median: 0,1,0, 0
Pts with ≥1 exacerbation in last 30 days48.3%, 52.9%, 48.1%, 36.7%
 Woodcock et al.  (2002) [59]18–6586, 86Mean no. daytime asthma attacks in 7-day run-in0.25, 0.18
Mean no. night-time asthma attacks in 7-day run-in0.10, 0.10
Exacerbations reported in 12 months/1 year prior to study entry
 Bateman et al.  (2018) [26]12–832089, 2087Pts with 1 severe exacerbation in last 12 months17.5%, 17.3%
Pts with ≥1 severe exacerbations in last 12 months22%, 21.9%
Pts with ≥2 severe exacerbations in last 12 months4.5%, 4.7%
 Ding and Small  (2017) [49]≥12524, 591Pts with 1 exacerbation in last 12 months9.0%, 13.1%
Pts with ≥3 exacerbations in last 12 months3.4%, 1.9%
Mean (sd) no. of moderate-to-severe exacerbations in last 12 months0.2 (0.6)
Mean (sd) no. of exacerbations treated in ED or hospital in last 12 months0.1 (0.4), 0.1 (0.3)
Mean (sd) no. of exacerbations treated with OCS, antibiotics, ED or hospital admission in last 12 months+0.1 (0.5), 0.2 (0.6)
Pts with 1 exacerbation treated with OCS, antibiotics, ED or hospital admission in last 12 months+5.8%, 10.8%
Pts with ≥3 exacerbations treated with OCS, antibiotics, ED or hospital admission in last 12 months+1.0%, 1.5%
 Giraud et al.  (2006) [54]≥1894Pts hospitalised for asthma in previous 12 months4.3%
 Herjavecz et al.  (1999) [55]17–6790, 91Time since last exacerbation12.5 months, 13.0 months
 Lai et al. (2003)  [61]Mean 7.4–40.51709, 633Pts with hospital admissions in last year7.3%, 15.4%
Pts with any hospital ED/unscheduled emergency visit in the last year33.1%, 41.3%
 Martinez et al.  (2011) [36]5–1871, 72, 71,74Mean no. hospital visits for asthma in last 1 year0.3, 0.3, 0.2, 0.2
 O’Byrne et al.  (2018) [38]≥121277, 1277,1282Pts with ≥1 severe exacerbation in last 12 months20.0%, 20.1%, 18.8%
 Peters et al.  (2007) [56]≥6166, 165, 169Pts with ≥1 urgent visit for asthma in last 1 year30.7%, 35.8%, 35.5%
 Robertson et al.  (2007) [21]§2–1497, 105Median no. of ED attendances for asthma in last 1 year1, 1
Median no. of hospital admissions for asthma in last 1 year1, 1
 Soyer et al.  (2009) [60]6–18522Mean (sd) no. of unscheduled visits per patient1.2 (0.2)
Mean (sd) no. of ED visits per patient0.6 (0.05)
 Verbene et al.  (1996) [58]7–1630Pts hospitalised for asthma in last 1 year0%

All studies were randomised controlled trials except Giraud et al. [54], McIvor et al. [22], Ding and Small [49], Lai et al. [61] and Soyer et al. [60]. pts: patients; ED: emergency department; OCS: oral corticosteroids; no.: number. # Study included patients with a history of exacerbations (time frame not specified); n=1076; + time frame not specified in Results section of [49] although Methods section suggests 12-month timeframe; §: Study included only patients with a history of 3–6 exacerbations (hospitalisation or ED visit or general practitioner visits) in the 12 months prior to enrolment/screening.