Association of platelet count with 28-day mortality in medical-surgical ICU patients with sepsis: a multicenter retrospective cohort study

Abstract Background The association between platelet count and 28-day mortality in medical-surgical intensive care unit (ICU) patients with sepsis remains inconclusive. The aim of this study was to investigate whether platelet count is associated with 28-day mortality in these patients. Methods This retrospective cohort study extracted 6,122 adult patients with sepsis in medical-surgical ICU from the eICU Collaborative Research Database (eICU-CRD). The logistic regression models were used to estimate the covariates and investigate the relatioshiop between platelet count and 28-day mortality rate. Then, a generalized additive model (GAM) was used to investigate the dose-response relationship between the platelet count (every 10-unit change in platelet count) and 28-day mortality rate. Moreover, a two-piece-wise linear regression model was applied to assess the threshold effect of the platelet count and 28-day mortality rate. Results After adjustment for the covariates, the platelet count had a nonlinear relationship with 28-day mortality (P < 0.001). On the left side of the inflection point (platelet count < 127 x10ˆ9/L), an increase of 10 in the platelet count was associated with a 10% decreased risk 0f 28-day mortality rate (OR = 0.90, 95% CI = 0.87–0.93, P < 0.001). Nevertheless, when the platelet count ≥ 127 x10ˆ9/L, every 10-unit increase in platelet count was not significantly associated with 28-day mortality rate. Conclusion The relationship between platelet count and 28-day mortality rate in medical-surgical ICU patients with sepsis was nonlinear. This indicates that low platelet count may receive attention in medical-surgical ICU patients with sepsis.