Table 1– Study design
 Standard Exacerbation Standard t -3 -2 -1 0 e1 e2 e3 e4 +1 +2
• The baseline measurement was defined as the routine measurement before the clinical onset of an asthma exacerbation, denoted by t=0. The routine measurements before t=0 were coded t= -1, -2, -3, etc. The time interval between these measurements was 2 months. During the exacerbation, measurements were denoted by t=e1, e2, e3 and e4, referring to the additional measurements at day 1, 3 and 5, and at the end of the event, respectively. After the exacerbation, the standard measurements continued (denoted as t= +1, +2, etc.).