Symptom dimensions of anxiety and their association with mortality, hospitalization and quality of life in dialysis patients

Objective: Symptoms of anxiety are highly prevalent in dialysis patients and are associated with adverse clinical outcomes. Identifying symptom dimensions may help to understand the pathophysiology, improve screening and guide treatment. Currently, there are no data on symptom dimensions of anxiety in dialysis patients. This study aimed to identify the best fitting dimensional model for anxiety in dialysis patients and assess the association between symptom dimensions of anxiety and adverse clinical outcomes. Methods: This study is a prospective observational cohort study including patients from 10 urban dialysis centers between 2012 and 2017. Anxiety symptoms were measured using the self-reported questionnaire Beck Anxiety Inventory. Confirmatory factor analysis was used to identify symptom dimensions. The association between dimensions and mortality, hospitalization and quality of life was investigated using stepwise cox, poisson and lineair regression models. Multivariable models included demographic, social, laboratory and clinical variables to adjust for possible confounding. Results: In total 687 chronic dialysis patients were included. A Somatic and Subjective anxiety dimension were identified. Only Somatic anxiety symptoms showed an association with increased risk of hospitalization and mortality (Rate Ratio 1.73 (1.45–2.06) p = .007 and Hazard Ratio 1.65 (1.15–2.37) p = .007 respectively). These associations were independent from somatic comorbidity. All symptom dimensions of anxiety showed an association with Quality of Life. Conclusion: This study shows that anxiety is common in chronic dialysis patients and comprises of a somatic, subjective, and a total score. The discrimination between anxiety dimensions can be useful for clinical practice, as they are related to different clinical outcomes.