Cut-off values of MASK-air® Patient-Reported Outcome Measures (PROMs)

In clinical and epidemiological studies, cut-offs of Patient-Reported Outcome Measures (PROMs) can be used to classify patients into groups of statistical and clinical relevance. However, visual analog scale (VAS) cut-offs in MASK-air® have not been tested.To calculate cut-offs for VAS global, nasal, ocular, and asthma symptoms.In a cross-sectional study design of all MASK-air® participants, we compared (i) approaches based on the percentiles (tertiles or quartiles) of VAS distributions, and (ii) data-driven approaches based on clusters of data from two comparators (VAS work and VAS sleep). We then performed sensitivity analyses for individual countries and for VAS levels corresponding to full allergy control. Finally, we tested the different approaches using MASK-air® real-world cross-sectional and longitudinal data to assess the most relevant cut-offs.We assessed 395,223 days from 23,201 MASK-air® users with self-reported allergic rhinitis. The percentile-oriented approach resulted in lower cut-off values than the data-driven approach. We obtained consistent results in the data-driven approach. Following the latter, the proposed cut-off differentiating "controlled" and "partly-controlled" patients was similar to the cut-off value which had been arbitrarily used (20/100). However, a lower cut-off was obtained to differentiate between "partly-controlled" and "uncontrolled" patients (35 versus the arbitrarily-used value of 50/100).Using a data-driven approach, we were able to define cut-off values for MASK-air® VASs on allergy and asthma symptoms. This may allow for a better classification of rhinitis and asthma patients according to different levels of control, supporting improved disease management.