Fig. 4.

Clusters of the spirometry sequences over time (pooled data). After classifying each participant as normal, restrictive and obstructive at each time point, we clustered the individual participant's spirometry sequences. The grey colour represents missing values for the first or intermediate timepoints, whereas the white spaces represent loss to follow up. The normal cluster comprises those with Normal spirometry at all three time-points. In contrast, the Restrictive cluster comprises participants transitioning between normal and restrictive spirometry. The Obstructive cluster comprises participants mainly transitioning between normal and obstructive spirometry.