Table 1

Biomarker-stratified data and rate ratios derived from included trials

Blood Eos
Novel START4 CAPTAIN5 Pooled AZ trials:
Benralizumab 2b, PATHWAY, STRATOS 1–27
QUEST6 DREAM3 Aggregate data for the prototype risk scale
Step 1 asthma; low risk; 9% with attack in past 12 monthsStep 4 asthma; high risk; 62% with attack in past 12 months1% step 3 asthma, 50% step 4 asthma, 49% step 5 asthma; high risk; with attack in past 12 months47% step 4 asthma, 53% step 5 asthma; high risk; with attack in past 12 monthsStep 5 asthma; high risk; with attack in past 12 months
N†Attack rate‡Rate ratioNAttack rate‡Rate ratioN†Attack rateRate ratioNAttack rateRate ratioNAttack rateRate ratioNRate ratio
<0.15<25180.050.982280.850.541990.580.811060.560.52231.980.76574 0.65
25–<50230.000.00400.101.11820.460.64350.620.61(9)(1.78)(0.71)180 0.66
≥5080.000.00170.151.74230.570.81210.530.5369 0.86
0.15–<0.30<25190.071.502400.070.821910.560.76960.820.80121.540.59558 0.81
25–<50420.020.36870.070.791730.670.96531.141.17(23)(2.70)(1.07)355 0.88
≥50320.010.24240.121.43521.291.93250.480.47133 1.16
≥0.30<2540.306.352480.111.291020.580.82890.840.84181.950.75461 1.12
25–<50220.000.001470.091.001330.871.30971.241.31(66)(3.08)(1.22)399 1.12
≥50510.134.40660.182.141071.011.53981.782.12322 2.29
  • Aggregate ratios in bold (rightmost column) are those included to derive the prototype risk scale: in effect, an aggregate rate ratio is a mean fold change in the asthma attack rate for patients with that biomarker combination. Numbers between brackets were extracted to calculate frequency-weighted rate ratios but were not used to derive the scale, as this analysis was stratified using only two cut points for fractional exhaled nitric oxide (FeNO <25 or ≥25 ppb).

  • Blood Eos, peripheral blood eosinophil count; n, number of patients.

  • *Missing data were excluded from analyses.

  • †For Novel START and the pooled AstraZeneca (AZ) trials, we regrouped the data of patients with a baseline FeNO of 20–<50 ppb into our 25–<50 ppb group, as the difference of 5 ppb in FeNO is not clinically relevant.

  • ‡For both the Novel START and CAPTAIN, only the percentage of patients with one or more severe attack(s) in the 52 weeks of follow-up was reported, so we imputed the annualised rate as log10(1 − %incidence).