Table 3.

Relationship between early (0–7 days) changes in platelet count (10^9/L) and death in 532 COVID-19 patients derived from a generalized additive mixed model (GAMM)

Outcome	Model I		Model II
	β (95%CI)	p value	β (95%CI)	p value
Intercept	167.9 (141.5, 194.2)	< 0.0001	168.9 (142.1, 195.74)	< 0.0001
Day	2.9 (2.4, 3.5)	< 0.0001	2.9 (2.4, 3.5)	< 0.0001
Death	− 27.9 (− 55.7, − 0.1)	0.05	− 27.9 (− 56.1, 0.1)	0.0509
Day × death	− 5.3 (− 7.1, − 3.4)	< 0.0001	− 5.3 (− 7.1, − 3.4)	< 0.0001

CI, confidence interval; Intercept, the mean of platelet count at day = 0 and death = 0; Day, the mean of the increasing of platelet count at death = 0 over time (daily); Death, the difference of platelet count at day = 0 between the group of death = 1 and the group of death = 0; Day × death, the average increasing in platelet count daily under the condition of the group of death = 1 compared with the group of death = 0; Model I: adjusted for Sex; Age, years; Neutrophil count, 10^9/L; Lymphocyte count, 10^9/L; Model II: adjusted for Sex; Age, years; White blood cell count, 10^9/L; Neutrophil count, 10^9/L; Lymphocyte count, 10^9/L; History of hypertension; History of diabetes