Development and Initial Validation of the Asthma Severity Scoring System (ASSESS)

Abstract Background Tools for quantification of asthma severity are limited. Objective To develop a continuous measure of asthma severity, the Asthma Severity Scoring System (ASSESS), for adolescents and adults incorporating domains of asthma control, lung function, medications, and exacerbations. Methods Baseline and 36-month longitudinal data from participants in Phase 3 of the Severe Asthma Research Program (SARP, NCT01606826) were utilized. Scale properties, responsiveness, and a minimal important difference (MID) were determined. External replication was performed in participants enrolled in SARP Phase 1/2. Utility of ASSESS for detecting treatment response was explored in participants undergoing corticosteroid responsiveness testing with intramuscular triamcinolone and participants receiving biologics. Results ASSESS scores ranged from 0 to 20 (8.78 ± 3.9; higher scores reflect worse severity) and differed between 5 phenotypic groups. Measurement properties were acceptable. ASSESS was responsive to changes in quality of life with a MID of 2, with good specificity for outcomes of asthma improvement and worsening, but poor sensitivity. Replication analyses yielded similar results, with a 2-point decrease (improvement) associated with improvements in quality of life. Participants with ≥2 point decrease (improvement) in ASSESS scores also had greater improvement in lung function and asthma control after triamcinolone, but these differences were limited to phenotypic clusters 3, 4 and 5. Participants treated with biologics also had ≥2 point decrease (improvement) in ASSESS scores overall. Conclusions The ASSESS tool is an objective measure that may be useful in epidemiologic and clinical research studies for quantification of treatment response in individual patients and in phenotypic groups. However, validation studies are warranted.