Nighttime intensive care unit admission increased 30-day mortality in sepsis patients: a retrospective propensity-score matched analysis based on MIMIC-IV database

Although there has been extensive research on the mortality and prognosis of sepsis, none of them has been focused on the association between mortality and timing of admission to intensive care unit (ICU) in sepsis patients. This study used MIMIC-IV data to compare mortality risk between daytime and nighttime ICU admission in sepsis patients. Propensity score matching (PSM) balanced baseline characteristics. Kaplan-Meier survival analysis and multivariable Cox regression were performed. Results of primary outcome showed after adjustment for covariates, nighttime admission was associated with a significantly higher 30-day mortality in both full cohort (1798 [15.05%] vs 3003 [22.26%], adjusted HR [95% CI] = 1.219 [1.148-1.293], p < 0.001) and PSM cohort (1704 [19.58%] vs 1805 [21.25%], adjusted HR [95% CI] = 1.081 [1.012-1.154], p = 0.021). Nighttime admission was also associated with increased 90- and 180-day mortality and higher incidences of sepsis-associated encephalopathy (SAE) and sepsis-induced acute lung injury (S-ALI). Subgroup and sensitivity analyses supported consistent associations across patient subgroups. Thus, nighttime ICU admission in sepsis patients may be associated with increased short- and long-term mortality risks and higher rates of SAE and S-ALI, indicating an important factor in prognosis of sepsis.