Individual clusters revealed unique clinical differences in baseline cognition, frailty, delirium burden, physiological derangements and premorbid prescriptions (Fig. 2, full variables of each cluster in Additional file 4: Supplementary Fig. 2): cluster 1 was composed of participants with higher measures of baseline cognition (MMSE item scores, fewer years of education), lower premorbid frailty (lower clinical frailty score, higher Barthel Index), lower burden of delirium during acute illness (lower MDAS and OSLA scores), biochemically demonstrated lower C-reactive protein and creatinine. The gene discussed is CRP; the disease is delirium.