Technical validity and usability of a novel smartphone-connected spirometry device for pediatric patients with asthma and cystic fibrosis.

"CONFLICT OF INTERESTS The authors declare that there are no conflict of interests."

"The authors would like to thank Mohamed Chouchouh el Khattabi for performing the variability assessments, the pulmonary function technicians for performing the conventional pulmonary function tests, and the clinical trial assistants and other support staff at the Centre for Human Drug Research. The study was funded by the Centre for Human Drug Research. This was an investigator‐initiated study by the Centre for Human Drug Research, an independent clinical research foundation in Leiden, the Netherlands."

"This study was conducted at the Juliana Children's Hospital (HAGA teaching hospital, The Hague, The Netherlands) and Sophia Children's Hospital (Erasmus Medical Centre, Rotterdam, The Netherlands) from November 2018 to January 2020. The study protocol was reviewed and approved by the Medical Ethics Committee, Zuidwest Holland (The Hague, The Netherlands) before initiation of the study. The study was conducted according to the Dutch Act on Medical Research Involving Human Subjects (WMO) and in compliance with Good Clinical Practice. Written informed consent was obtained from all parents and children aged 12 years and older. Assent was obtained from children aged younger than 12. The trial was registered at the Dutch Trial Registry (NTR, Trial NL7611)."