![](https://lifeboat.com/blog.images/hemoglobin-value-may-be-decreased-in-patients-with-severe-coronavirus-disease-2019.jpg)
The recent infective outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), now officially defined as coronavirus disease 2019 (COVID-19), has already affected over 1million people from nearly all countries worldwide, causing approximately 66,000 deaths. 1 The clinical characteristics of this pandemic disease may be complicated by the onset of a severe form of intestinal pneumonia in 10–15% of infected patients, which may then progress toward acute respiratory distress syndrome (ARDS) and eventually in multi-organ failure (MOF) and death. 2 Since laboratory hematology is a mainstay for screening, diagnosis, but also for prognostication and therapeutic monitoring of a kaleidoscope of human disorders, 3 the aim of this article was to investigate whether or not hemoglobin values may be a predictive factor of worse clinical progression in patients with COVID-19.
We performed an electronic search in Medline, Web of Science and Scopus, using the keywords “laboratory” OR “hemoglobin” AND “coronavirus 2019” OR “2019-nCoV” OR “SARS-CoV-2”, between 2019 and the present time (i.e., March 4, 2020), with no language restriction. The title, abstract and full text of documents identified according to these search criteria were analyzed and those reporting information on the hemoglobin values in COVID-19 patients with or without severe disease (i.e., those needing mechanical ventilation, intensive care unit (ICU) admission or those who died), were meta-analyzed. The reference list of all documents was examined to identify additional eligible studies. The final meta-analysis entailed the estimation of the weighted mean difference (WMD) and 95% confidence interval (95% CI) of hemoglobin values between subjects with or without severe disease. The statistical analysis was performed with the MetaXL software, Version 5.3 (EpiGear International Pty Ltd.