Longitudinal Pulmonary Function
Doctoral research — reading repeated screening spirometry as a trajectory to anticipate incident airflow obstruction.
Status. Ongoing doctoral research. Presented as a late-breaking poster at the ERS International Congress 2026; not yet published as a paper.
Research question. In health screening, spirometry is repeated over many years, yet each result is usually read on its own. Does the trajectory of repeated tests carry information about future airflow obstruction beyond the latest value, and is a nonlinear sequence model needed to capture it?
Methods. A landmark design: at three years after the first test, predict incident airflow obstruction (FEV1/FVC < 0.70) over the next five years using only earlier tests. Three readings of the same history are compared — the latest value, a linear trajectory summary (slope, variability, test count, span), and a sequence model that reads every measurement in order.
Data and validation. 557,503 screening spirometry tests from 221,903 adults with normal airflow at their first test, from Samsung Medical Center. Internal validation, with sensitivity analyses that exclude outcomes within one or two years of the landmark, require two consecutive obstructed tests, or restrict to a higher baseline FEV1/FVC. The data are retrospective and single-centre, without smoking or diagnosis labels; clinically performed pulmonary function tests and a multicenter external validation are the planned next steps.
My role. First author, with Dayoon Lee, Prof. Jin-Young Lee, and Prof. Byung-Jae Lee (doctoral advisor; corresponding author).
Links. Poster (PDF) · Conference notes