Table 2.

Roll out process.

•Clinicians provided a suitability and priority list of patients. •Child allocated suitable spirometer based on technique by the physiologist*. •Called parents to explain sending them a device and check they have a smart phone/table; and to confirm address. •Sent out in post spirometer with instructions for set up with a covering letter; and additional information including the child’s latest height, weight and ethnicity according to GLI reference ranges. •On receiving spirometer, patients and parents asked to set up and perform a spirometry session. •One of the devices had an automatic platform through which we received the data. The other one required parents to create a pdf from the accompanying app and email to us. •Once results received, physiologist checked acceptability/reproducibility in line with ATS/ERS criteria. •If satisfactory, results were uploaded to the patient’s electronic record so clinicians could access them. •Contacted patients if acceptability criteria not met and offered video call for further instruction. There was no time to offer video call routinely although this would have been preferable.

^*At first one of the spirometers did not give a flow volume loop so these were used for children we knew had reproducible technique; this was soon rectified.