Tinschert P, et al. – Researchers of this multicenter, longitudinal observational study with two stages aim to determine the prevalence and trends of nocturnal cough in asthma, develop and evaluate smartphone-based machine learning models for automated nocturnal cough detection and sleep quality assessment, and examine the potential of nocturnal cough frequency as a marker for asthma control in combination with sleep quality. Study participants include asthmatic adults. Although the design of the study prioritizes external validity rather than internal validity, selection bias due to poor adoption of technology in the elderly and the limited sample size could undermine the generalizability. The potential clinical usefulness of the investigated markers might vary considerably between subgroups of individuals with asthma due to the heterogeneity of asthma.