Abstract
Background: Asthma control can be defined in various ways.
Objectives: To investigate the association between current and long-term asthma control.
Methods: We included 418 children using ICS participating in the PACMAN-cohort study. Current asthma control (last week) was defined using the ACQ. Long-term asthma control (last year) was based on GINA guidelines. This was analysed for the four different seasons separately. Not well-controlled asthma was defined as: ≥3 of the following items present in a specific season: day-time or night-time symptoms, limitations in activities and rescue medication use. Secondly, this first definition was adjusted for the frequency of symptoms during a season. When asthma control was present in ≥3 seasons we qualified this as long-term asthma control (control during the past year). Current and long-term asthma control were compared to investigate agreement.
Results: Long-term uncontrolled asthma rates were highest in winter (51%) and lowest in summer (33%) (P < 0.05). 42% of the patients did not have long-term asthma control during the past year. Overall agreement between current and long-term asthma control was 67% and kappa statistics (≤ 0.39) indicated “poor agreement”.
Conclusion: The congruence between current and long-term asthma control is poor in our cohort of asthma children using ICS. There existed significant seasonal differences in asthma control. In observational studies assessing asthma control, it is therefore important to calculate long-term asthma control (instead of using current asthma control as indicator) or to stratify at least for seasonal variation.
- © 2011 ERS