2017/2018 Cohort
The Hopkin’s statistic for 2017/2018 was 0.810. The 3-cluster model was selected with the highest average silhouette width of 0.15 (Figure 1). The silhouette plots indicate the possibility of minor misclassification of some individuals. There were significant differences in race, age, CCI, and diabetes between clusters (Table 2). For the variables included in the PAM algorithm, those in Cluster 1 (C171) had significantly higher mean glucose (minimum mean 210.4mg/dL, SD 66.9) than those in Cluster 2 (C172) (minimum mean 90.5mg/dL, SD 16.4) and Cluster 3 (C173) (minimum mean 110.0mg/dL, SD 26.7). Those in C172 had significantly lower maximum heart rate, maximum systolic blood pressure, minimum white blood cell count, minimum platelets, and estimated glomerular filtration rate than the other two clusters. Those in C172 also had significantly higher maximum creatinine than the other clusters. The rate of being mechanically ventilated was higher in C171 than C172 (22.6% vs. 6.9%), and the overall hospital length of stay was longer for those in C171 than C173 (mean 4.5 days (SD 4.4) vs. mean 2.8 days (SD 2.4)).
After adjustment for age group, sex, hospital, continuous CCI, and influenza vaccination status, those in C171 had 5.6 times the odds of having a mechanical ventilator than those in C172 (95%CI:1.49,21.1; Figure 2). Additionally, those in C171 had a significantly longer model-adjusted mean hospital length of stay than those in both C172 (mean 1.5 days longer, 95%CI:0.2,2.7) and C173 (mean 1.4 days longer, 95%CI:0.3,2.5). There were no significant differences between clusters for the outcomes of ICU stay or prolonged hospital stay. Vaccination status was not associated with adverse outcomes in the fully adjusted models.