BackgroundAllergic rhinitis (AR) and asthma may impact health-related quality-of-life. However, national estimates on the quality-of-life of patients with AR or asthma are lacking. ObjectiveTo provide estimates for utility scores and EQ-5D Visual Analog Scale (VAS) for patients with AR or asthma. MethodsWe conducted a cross-sectional study using direct patient data from the MASK-air® app on European MASK-air® users with self-reported AR or asthma. We used a multiattribute instrument (EQ-5D) to measure quality-of-life (as utility scores and EQ-5D VAS values). Mean scores were calculated per country and disease control level using multilevel regression models with post-stratification, accounting for age and sex biases. ResultsWe assessed data from up to 7905 MASK-air® users reporting a total of up to 82,737 days. For AR, utilities ranged from 0.86-0.99 for good control versus 0.72-0.85 for poor control; EQ-5D VAS levels ranged from 78.9-87.9 for good control versus 55.3-64.2 for poor control. For asthma, utilities ranged from 0.84-0.97 for good control versus 0.73-0.87 for poor control; EQ-5D VAS levels ranged from 68.4-81.5 for good control versus 51.4-64.2 for poor control. Poor disease control was associated with a mean loss of 0.14 utilities for both AR and asthma. For the same control levels, AR and asthma were associated with similar utilities and EQ-5D VAS levels. However, lower values were observed for asthma+AR when compared to AR alone. ConclusionPoor AR or asthma control are associated with reduced quality-of-life. The estimates obtained from mHealth data may provide valuable insights for health technology assessment studies.