Heatmaps showing prevalence of binary features within each cluster found by each approach. OXY refers to use of oxygen therapy and LOS refers to the length of stay. Note that the features shown in the third row, Demographic information, were not used for clustering - they are shown only to aid interpretation of the clusters. For the Layered Axes K-Modes clusters, labels are in the form number-letter where the number indicates the clusters found from the first axis, and the letter the subclusters found within that cluster using features from the second axis. Note also that for the Prognosis Space approach, DBSCAN has been used and -1 indicated points described as ‘noise’.