Figure 2.

Nonlinear association between age and 28-day mortality stratified by number of risk factors. Nonlinear association of age (continuous) with 28-day mortality stratified by categories of the number of significant preexisting comorbidities and acute physiologic ICU factors. p for nonlinearity in each group less than 0.001. Risk factors: male sex, hypertension, diabetes mellitus, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, active cancer, symptom onset less than or equal to 3 d, lymphocyte count less than 1,000/µL, invasive mechanical ventilation, shock, SOFA Coagulation Score greater than 0, SOFA Renal Score greater than 0, SOFA Liver Score greater than 0, and number of ICU beds less than 100. Models are further adjusted for body mass index (in categories), White versus non-White, current smoker, remdesivir, tocilizumab, and corticosteroids. SOFA = Sequential Organ Failure Assessment.