The occurrence of delirium was significantly associated with the variables age (p = 0.01), prior history of neurodegenerative disease (p < 0.0001), COVID-19 disease severity as captured by the WHO grading scale (p < 0.0001) and the need for ICU admission (p < 0.0001), the inflammatory parameters leukocyte count, CRP, PCT and IL-6 (each p < 0.0001), and the renal function parameters BUN and creatinine (each p < 0.0001; all p-values corrected for multiple comparisons, see Table 2). This evidence concerns the gene CRP and neurodegenerative disease.