Subgroups of ICU patients identified by self-reported symptoms - A prospective multicenter study

Background: Intensive care unit (ICU) patients experience several symptoms, yet patterns of symptoms and their relationship with demographic and clinical characteristics have not previously been investigated. Objectives: To identify and compare subgroups (i.e. latent symptom classes) of intensive ICU patients based on prevalence of co-occurring symptoms over seven days. Research methodology: Prospective cohort study of adult ICU patients ' self-reports of five symptoms during seven days in ICU. Latent class analysis was applied to identify subgroups of ICU patients. Setting: Multicenter study with patients from six mixed ICUs in Norway. Main Outcome Measures: Patient Symptom Survey was used to assess five symptoms (i.e., thirst, pain, anxiousness, tiredness, shortness of breath). Results: Among 353 included patients, median age was 63 years and 60.3 % were male. Subgroups of patients were identified in a Low class (n = 126, 35.7 %), Middle Class (n = 177, 50.1 %) and High Class (n = 50, 14.2 %) based on reporting of the prevalence of five symptoms. Patients in the Low class had a low prevalence of all symptoms. Middle Class patients had a high prevalence of thirst and tiredness and a low prevalence of pain, anxiousness and shortness of breath. The High class patients had a high prevalence of all symptoms. Symptom prevalence remained stable in the Low and Middle class over time and increased over time in the High class. There were significant differences among symptom classes in use of mechanical ventilation (p = 0.012), analgesics (p < 0.001), alpha-2 agonists (p = 0.004) and fluid restriction (p = 0.006). Patients in the High class received more of these ICU-treatments. Conclusions: Findings suggest that subgroups of ICU patients with distinct symptom experiences can be identified. The High prevalence class patients had consistently high levels of all symptoms across seven ICU days and received more ICU-related interventions. Implication for clinical practice: Some ICU patients experience a consistently high prevalence of co-occurring symptoms. Clinicians should be aware of treatment factors that could be linked to a high burden of symptoms.