Differences in long-term outcomes between ICU patients with persistent delirium, non-persistent delirium and no delirium: A longitudinal cohort study

Purpose: Determine differences in physical, mental and cognitive outcomes 1-year post-ICU between patients with persistent delirium (PD), non-persistent delirium (NPD) and no delirium (ND). Materials and methods: A longitudinal cohort study was performed in adult ICU patients of two hospitals admitted between July 2016-February 2020. Questionnaires on physical, mental and cognitive health, frailty and QoL were completed regarding patients' pre-ICU health status and 1-year post-ICU. Delirium data were from patients' total hospital stay. Patients were divided in PD (>= 14 days delirium), NPD (<14 days delirium) or ND patients. Results: 2400 patients completed both questionnaires, of whom 529 (22.0%) patients developed delirium; 35 (6.6%) patients had PD and 494 (93.4%) had NPD. Patients with delirium (PD or NPD) had worse outcomes in all domains compared to ND patients. Compared to NPD, more PD patients were frail (34.3% vs. 14.6%, p = 0.006) and fatigued (85.7% vs. 61.1%, p = 0.012). After adjustment, PD was significantly associated with long-term cognitive impairment only (aOR 3.90; 95%CI 1.31-11.63). Conclusions: Patients with PD had a higher likelihood to develop cognitive impairment 1-year post-ICU compared to NPD or ND. Patients with PD and NPD were more likely to experience impairment on all health domains (i.e. physical, mental and cognitive), compared to ND patients.