TABLE 1

Model inputs

ParameterMeanDistributionReference
Probabilities
 Prevalence of asthma323 500Fixed[19]
 Percentage of mild asthma67.1%Fixed[4]
 Prevalence of genetic abnormality (GSTT1 null, GSTM1 null or GSTP1 Ile105)25%Fixed[20, 21]
 Risk of additional exacerbation in asthmatics with genetic abnormality, without preventive intervention55%Beta (42.7, 34.9)[22, 23]
 Risk of additional exacerbation in asthmatics with genetic abnormality, with preventive intervention5%Beta (91.2,1732.5)[22, 23]
 Risk of additional exacerbation in asthmatics without genetic abnormality (with or without preventive intervention)0Fixed
Unit costs
 Advair 500/50 twice per day (per month)$74.7Fixed[19]
 Exacerbation without hospitalisation$126Gamma (96.04,0.76)[24]
(Converted to 2018 CAD)
 Exacerbation requiring emergency room visits$575Gamma (96,0.17)[24]
(Converted to 2018 CAD)
 Exacerbation requiring hospitalisations$6440Gamma (96,0.014)[24]
(Converted to 2018 CAD)
 Genetic testing109.43Fixed[25]
(Converted to 2018 CAD)
Utilities
 Exacerbation without hospitalisation0.57Beta (0.51, 0.38)[26]
 Exacerbation requiring emergency room visits0.45Beta (0.36, 0.45)[26]
 Exacerbation requiring hospitalisations0.33Beta (0.15, 0.30)[26]
  • CAD: Canadian dollars.