Table 2 Unadjusted hazard ratio (95% CI) for 90-day survival probability by clusters

At baseline

 Cluster 1 (n = 1402)

383 (27.3%)

Reference

 Cluster 2 (n = 2341)

1025 (43.8%)

1.82

1.62–2.05

Day 3

 Cluster 1 (n = 1557)

321 (20.6%)

Reference

 Cluster 2 (n = 2086)

1023 (49.0%)

2.97

2.62–3.37

Change from baseline to day 3

 From 1 to 1 (n = 919)

172 (18.7%)

Reference

 From 1 to 2 (n = 458)

200 (43.7%)

2.77

2.26–3.40

 From 2 to 1 (n = 638)

149 (23.4%)

1.26

1.02–1.58

 From 2 to 2 (n = 1628)

823 (50.6%)

3.45

2.93–4.07