Journal Article Annotations
2023, 1st Quarter

Critical Care

Annotations by Natalie Fedotova, MD, PhD
April, 2023

Association Between Preexisting Mental Health Disorders and Adverse Outcomes in Adult Intensive Care Patients: A Data Linkage Study.

PUBLICATION #1 — Critical Care

Association Between Preexisting Mental Health Disorders and Adverse Outcomes in Adult Intensive Care Patients: A Data Linkage Study.

Julia K Pilowsky, Rosalind Elliott, Michael A Roche

Abstract: Crit Care Med. 2023 Apr 1;51(4):513-524. doi: 10.1097/CCM.0000000000005792. Epub 2023 Feb 8.

Objectives:
Mental illness is known to adversely affect the physical health of patients in primary and acute care settings; however, its impact on critically ill patients is less well studied. This study aimed to determine the prevalence, characteristics, and outcomes of patients admitted to the ICU with a preexisting mental health disorder.

Design:
A multicenter, retrospective cohort study using linked data from electronic ICU clinical progress notes and the Australia and New Zealand Intensive Care Society Adult Patient Database.

Setting/patients:
All patients admitted to eight Australian adult ICUs in the calendar year 2019. Readmissions within the same hospitalization were excluded.

Interventions:
None.

Measurements and main results:
Natural language processing techniques were used to classify preexisting mental health disorders in participants based on clinician documentation in electronic ICU clinical progress notes. Sixteen thousand two hundred twenty-eight patients (58% male) were included in the study, of which 5,044 (31.1%) had a documented preexisting mental health disorder. Affective disorders were the most common subtype occurring in 2,633 patients (16.2%), followed by anxiety disorders, occurring in 1,611 patients (9.9%). Mixed-effects regression modeling found patients with a preexisting mental health disorder stayed in ICU 13% longer than other patients (β-coefficient, 0.12; 95% CI, 0.10-0.15) and were more likely to experience invasive ventilation (odds ratio, 1.42; 95% CI, 1.30-1.56). Severity of illness and ICU mortality rates were similar in both groups.

Conclusions:
Patients with preexisting mental health disorders form a significant subgroup within the ICU. The presence of a preexisting mental health disorder is associated with greater ICU length of stay and higher rates of invasive ventilation, suggesting these patients may have a different clinical trajectory to patients with no mental health history. Further research is needed to better understand the reasons for these adverse outcomes and to develop interventions to better support these patients during and after ICU admission.

Annotation

The finding:
This multicenter, retrospective cohort study examined the connection between preexisting mental health disorders (PMHDs) and various outcomes from first episode ICU admissions in calendar year 2019, from eight general hospital ICUs across New South Wales, Australia. Patients with PMHDs were more likely to require invasive ventilation and had longer ICU lengths of stay (LOS). These patients also tended to be younger—despite a similar severity of illness on admission (based on APACHE3), were more likely to have an unplanned admission, were more likely to be admitted with a trauma-related diagnosis, required ventilation for a greater duration, and were more likely to experience delirium. Patients with PMHDs did not differ in terms of mortality or readmission rate.

Strength and weaknesses:
This is a multicenter study that was able to include a high percentage of eligible patients and used natural language processing techniques on clinical progress notes rather than relying on ICD codes to identify PMHDs (90% accuracy compared to gold standard manual chart review). The main analysis, however, collapsed across various subtypes of mental health disorders (e.g., affective disorders, anxiety, schizophrenia, substance use, alcohol use, etc.), which may have different trajectories and pose distinct—though overlapping—challenges in the critical care setting.

Relevance:
The data on ICU outcomes—including mortality and length of stay (LOS)—for patients with PMHDs are mixed. This study adds to the existing literature in a unique way: by showing that LOS and need for ventilation appear to be higher in patients with PMHDs but without a comparable increase in mortality. C-L psychiatrists are particularly well positioned to address many of the potential reasons for less favourable outcomes in the PMHD population in the ICU, including addressing anxiety and motivation to engage in early mobilization, maintaining access to home psychotropic regimens as appropriate, preventing/diagnosing and effectively managing delirium, and managing agitation in the peri-extubation phase to facilitate a successful outcome.