Table 3

Multivariate logistic regression analysis of factors associated with marked airway hyper-responsiveness (HisPC20<2 mg/mL) in young patients with untreated intermittent adult-onset asthma

(Reference)Adjusted† OR
(95% CI)
P valueAdjusted† OR
(95% CI)
P value
Number of cigarettes per day (pseudo R2‡=0.064)
Never smoker1–10§≥11
n=137n=39n=37
HisPC20<2 mg/mL11.43 (0.68 to 3.00)0.341 2.23 (1.03 to 4.80)* 0.041
Duration of smoking (years) (pseudo R2‡=0.058)
Never smoker1–7 years§≥8 years
n=137n=36n=40
HisPC20<2 mg/mL11.72 (0.80 to 3.67)0.1641.83 (0.85 to 3.94)0.120
Cumulative consumption, pack-years (pseudo R2‡=0.059)
Never smoker0<pack-years≤4§>4 pack-years
n=137n=38n=38
HisPC20<2 mg/mL11.62 (0.78 to 3.40)0.1991.96 (0.90 to 4.26)0.090
  • Results highlighted in bold indicate statistically significant findings.

  • *P<0.05.

  • † Adjusted for sex, age, disease duration (log transformed) and BMI.

  • ‡ McFadden.

  • §Current smokers were stratified on the basis of the median value for each smoking parameter.

  • BMI, body mass index; HisPC20, provocative concentration of histamine leading to a decrease in the forced expiratory volume in 1 s by>20%.