Abstract
Background Asthma comprises of several phenotypes which are still not well defined. Little is known about change over time of clinically important characteristics of asthma.
Aim To study stability of clinical characteristics in a randomly selected adult asthma cohort.
Method: From a population study, 744 subjects with current asthma were identified by detailed clinical examinations. Of them, 64 randomly selected asthmatics were re-evaluated with identical methods. Mean follow-up time was 3.5y (SD 1.0). Mean age at follow up was 46y (SD 18).
Results Asthma medications were used by 59 subjects at both visits, and altogether 61 used medications at follow-up. ICS (alone or in combination) were used by 42 at the first visit, 5 of whom discontinued, and in all 44 used ICS at the follow-up. Wheeze in the last 12 months was initially reported by 51, 7 of whom ceased to complain, and in all 48 reported wheeze at follow-up. The repeatability of attacks of shortness of breath, allergic rhinitis and ACT-scores was high, as well as the proportion of those with post bronchodilator FEV1/FVC <0.7. The sensitization profile and FeNO were stable. Regarding GINA status, 7 were uncontrolled at both examinations, 4 changed from either controlled to uncontrolled or vice versa, while all others remained at similar level of control. The only significant changes in the follow-up were a lower FEV1% (87% vs 94% pred, p<0.001) and a low repeatability of sputum production, longstanding cough and chronic productive cough.
Conclusion Clinical characteristics remained stable over 3-4 years in this well-defined asthma cohort, except for FEV1 and variability in symptoms of bronchitis. These preliminary data suggest relative stability of asthma phenotype characteristics in adults.
- © 2014 ERS