Rationale: Mobile electronic health journals (EHJ) which capture patient-reported health outcomes in real time have potential to be a powerful tool for longitudinal studies of disease progression in chronic respiratory conditions. The patientMpower platform (pMp) is an EHJ developed for pulmonary fibrosis (PF) patients which enables them to regularly record medication adherence, activity, objective [e.g. forced vital capacity (FVC), oximetry] and subjective measurements (e.g. dyspnea) and other health outcomes (e.g. quality of life). Methods: pMp was evaluated in an open-label, single-arm, prospective, observational survey (6 weeks) of participants with PF enrolled through invitation by the PF Warriors support group. (Previously reported: Am J Respir Crit Care Med 2018; 197: A4932.) After the 6-week observation period, participants were free to use pMp with home spirometry (MIR Spirobank Smart) as often as they wished. There were no prompts to record spirometry. This report describes the pattern of participants’ use of pMp in a real-world setting over 12 months of observation. Results: 23 (100%) participants [12 f/11 m; mean 61Y; mean FVC 64% predicted] used pMp and provided spirometry data. There was wide variation in duration and frequency of recording of spirometry on pMp over 365 days (see Figure). Eighteen (78%) participants recorded spirometry ≥once after 6 weeks, 16 (69%) after 90 days and 6 (27%) at or after day 360. Eight participants (35%) recorded spirometry on ≥25% of days and 4 (17%) recorded on ≥50% of days over a 365-day period. Six participants (26%) provided dyspnea data and 5 (22%) provided oxygen saturation data on multiple occasions for ≥180 days. Conclusions: Electronic informed consent and remote installation of healthcare apps (with associated sensor devices) is feasible for observational studies for some patient populations with PF. Recruiting participants for observational studies via patient support groups is achievable. This approach is useful to capture patient-reported long-term trends in PF and generate richer real-world evidence. Long-term use of the patientMpower EHJ with integrated spirometry is acceptable and feasible for some PF patients, even if not involved in a formal study or survey. It is anticipated that prompts to record home spirometry and other data would result in more sustained and frequent collection of data. We would like to thank the PF Warriors for their participation.