Table 3

Changes in indices of exacerbation baseline, recovery and nonrecovery over time

Starting valueAnnual change95% CIp‐valueExacerbations nSubjects n
 Symptom count#0.36−0.012−0.04–0.010.3521045123
 PEF L·min−1234−2.8−4.3–−1.30.0001043123
 FEV1 mL1034−34.5−52–−160.00022132
 FVC mL185618.0−53–900.62319931
At exacerbation onset
 Symptom count2.230.034−0.013–0.080.1531045123
 PEF L·min−1217−0.81−2.1–0.570.2491011123
 FEV1 mL966−17.8−36–0.20.05221232
 FVC mL174339.6−7.4–8.60.09919031
Recovery time
 Symptom count day8.40.320.20–0.440.000945122
 PEF day7.8−0.07−0.18–0.030.163922122
 FEV1 day6.10.550.26–0.850.00019931
Nonrecovery >35 days
 Symptom count1.000.88–1.140.9941045123
  • A normal distribution was assumed for data at baseline and at exacerbation onset

  • A poisson distribution was assumed for data on recovery, and a binomial distribution for nonrecovery

  • CI: confidence interval

  • PEF: peak expiratory flow

  • FEV1: forced expiratory volume in one second

  • FVC: forced vital capacity

  • #: symptom count the sum of the seven respiratory symptoms recorded each day, with presence/increased scored 1 and absence 0

  • : the change from 1 yr to next in nonrecovery, data presented as odds ratio