Association between phase angle and adverse clinical outcomes in hospitalized patients with COVID-19: A systematic review.

Phase angle, obtained by bioelectrical impedance, is an indicator of cellular integrity and has been proposed as a prognostic parameter in patients who are critically ill. This systematic review aimed to evaluate the association between phase angle and adverse clinical outcomes in hospitalized patients with coronavirus disease-2019 (COVID-19). An extensive literature search was performed in the MEDLINE/PubMed, Embase, and Web of Science databases, with interest in observational studies evaluating the association between phase angle and adverse clinical outcomes in individuals aged ≥18 years hospitalized with COVID-19. Studies were independently selected by two reviewers, according to eligibility criteria. Subsequently, data were extracted and presented in a qualitative synthesis. The evaluation of the quality of the studies was performed according to the Newcastle-Ottawa scale. The full methodology was published in PROSPERO (ID CRD42022306177). A total of 392 articles were identified, resulting in seven selected studies, of which six were prospective cohorts and one was retrospective. In the quality assessment, six studies obtained scores equal to or greater than seven, indicating a low risk of bias. A total of 750 participants composed the samples of the selected studies. Five studies reported an independent association between phase angle and adverse clinical outcomes during hospitalization for COVID-19, with emphasis on prolonged hospitalization and mechanical ventilation and higher mortality in patients with a lower phase angle. Thus, phase angle measurement can be useful in the early identification of risks in patients hospitalized with COVID-19, for the purpose of adequacy of clinical management.