Table 4—

Relative risk between sputum strategy and clinical strategy from Cox regression models for the time to the first exacerbation and Andersen-Gill models for the multiple exacerbations during maintenance phase

Time to first exacerbation#Multiple event analysis
RR95% CIp-valueRR95% CIp-value
All exacerbations0.61(0.37–1.02)0.060.71(0.45–1.12)0.14
By type of exacerbation
By use of LABA
 Not on LABA0.84(0.44–1.63)0.611.05(0.62–1.79)0.85
 On LABA0.40(0.18–0.88)0.020.53(0.24–1.14)0.11
By asthma severity
 Very mild to mild0.99(0.34–2.81)0.981.34(0.52–3.46)0.54
 Moderate to severe0.51(0.29–0.90)0.020.63(0.38–1.03)0.07
  • RR: relative risks; 95% CI; 95% confidence intervals; LABA: long-acting β2-agonists. #: RR is relative risk from a Cox regression model. : RR is relative risk from an Anderson-Gill model. Asthma severity was based on minimum daily maintenance fluticasone equivalent dose, very mild: 0; mild: <250 µg; moderate: ≥250–500 µg; severe: >500 µg.