Development and Preliminary Validation of the Asthma Intensity Manifestations Score (AIMS) Derived from Asthma Control Test, FEV₁, Fractional Exhaled Nitric Oxide, and Step Therapy Assessments

Abstract

Objective. Inherent asthma severity is difficult to assess clinically. The purpose of this study was to develop an Asthma Intensity Manifestations Score (AIMS) as a surrogate for asthma severity. Methods. Three hundred and four patients treated with inhaled corticosteroids completed the Asthma Control Test (ACT), underwent spirometry, and fractional exhaled nitric oxide (FENO) testing, and reported their current medications. These parameters (defined as ACT < 16, forced expiratory volume in 1 second [FEV₁] < 80% predicted, FENO > 50 ppb, and Expert Panel Report [EPR3] step care level >3) were related to prior year outcomes to develop the AIMS and to follow-up year outcomes to validate it. Results. FENO was independently related to prior year short-acting beta agonist (SABA) ≥ 7 (odds ratio [OR] 2.9); ACT (OR 4.9), FEV₁ (OR 3.3), and step care (OR 3.9) were independently related to prior year systemic corticosteroid (SCS) ≥ 2. Thus, all the four items were chosen for the AIMS (0–4 points). AIMSs were linearly related to follow-up year SABA ≥ 7, any SCS, SCS ≥ 2, and emergency hospital care (all p < .01). Compared to patients with AIMSs <2, patients with AIMSs ≥2 were at more than a fourfold greater risk of requiring ≥2 SCS in the following year and were at a 2–2.8-fold greater risk of experiencing other adverse outcomes during that time period. Conclusions. The AIMS is linearly related to future year adverse asthma outcomes. Further studies will be necessary to confirm its utility as a surrogate for asthma severity in clinical practice and clinical research.

• asthma control
• asthma exacerbations
• asthma impairment
• asthma risk
• asthma severity
• exhaled nitric oxide
• spirometry

Acknowledgements

The authors thank Kjell Alving, M.D., for his helpful suggestions regarding this manuscript. The study was supported by investigational grants to the Southern California Permanente Medical Group Research and Evaluation Department from Aerocrine AB, Solna, Sweden, and Panasonic Shikoku Electronics Co., Ltd., Tõon City, Ehime, Japan.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.