The Italian severe/uncontrolled asthma registry (RItA): A 12-month clinical follow-up

Background: follow-up studies on registries of severe/uncontrolled asthma (SUA) patients are scanty.

Objective: to analyze baseline and follow-up characteristics of SUA patients and their longitudinal patterns.

Methods: 180 adult patients (age ≥15 yrs) were investigated at baseline and 12-month follow-up through the Italian SUA registry (RItA). Latent transition analysis (LTA) was performed to detect cross-sectional SUA phenotypes and longitudinal patterns. Risk factors for longitudinal patterns were assessed through logistic regression.

Results: a significant/borderline improvement of asthma control outcomes in the last 2-4 weeks emerged at follow-up with respect to baseline for: daily activities limitations (Δ -16%), frequent diurnal symptoms (Δ -25%), uncontrolled asthma symptoms according to ACT (Δ -26%). Last 12-month use of oral corticosteroids was less frequent at follow-up than at baseline (Δ -25%). Health status improvement was confirmed by lung function test results. Through LTA, two longitudinal patterns were detected considering last 12-month control outcomes: "persistence/worsening" (53.9%), "under control/improvement" (46.1%). A lower likelihood of having "persistence/worsening" SUA was exhibited by patients under anti-IgE (OR 0.38, 95% CI 0.17-0.84) and inhaled corticosteroids-bronchodilator association treatment (OR 0.13, 95% CI 0.01-1.26, borderline value), while a higher likelihood was shown by older age at first asthma diagnosis (OR 1.04, 95% CI 1.01-1.07).

Conclusion: the implementation of a SUA registry, the availability of patient-level data and the application of an innovative longitudinal analysis allowed to observe a general improvement in asthma control, one year after baseline, and a lower risk of SUA "persistence/worsening" in patients under anti-IgE and regular ICS-bronchodilator association use.