Table 3—

Summary of the stepwise logistic regression analysis for the effects of initial provocative dose causing a 20% fall in the forced expiratory volume in one second (PD20), duration of exposure, duration of follow-up and treatment with inhaled steroids among subjects with PD20 ≤1 mg and >1 mg at follow-up#

VariableModel 0Model 1Model 2Model 3
Initial PD20, log dose
Duration of exposure, yrs
Last exposure to TDI yrsNINI
Interval since removal from exposure yrs (≥10 <10)NI
Current inhaled steroids, yes versus no
  • #: dependent variable

  • PD20 ≤1 mg

  • Model: NI: variable not included in the model

  • 0: normal airway responsiveness (PD20 >1 mg)

  • 1: airway hyperresponsiveness (PD20 ≤1 mg)

  • 0: interval since removal from exposure ≥10 yrs

  • 1: interval since removal from exposure <10 yr

  • 0: no current inhaled steroids

  • 1: yes current inhaled steroids

  • B: regression coefficient

  • OR: odds ratio

  • CI: 95% confidence interval