Table 3.

Summary of studies evaluating the impacts of COVID-19 in patients with anemia and haematological malignancies

Country	Time of study	Patient	Results	Type of malignancy	Ref
Italy	Feb 25 and May 18, 2020	• 198 (37%) of 536 patients died • Compared to the general Italian population with covid-19, the standardized mortality ratio was 2.04 in our entire study group and 72.3 in people younger than 70 years • Compared to the non-COVID-19 group with haematological malignancies, the standardized mortality ratio was 41·3	People with haematological malignancies experience worse outcomes compared to the general population with COVID-19 and patients with haematological malignancies who are not infected with COVID-19	Leukaemias, myelodysplastic syndromes, myeloproliferative neoplasms, lymphomas, and MM	[214]
Turkey	11 March 2020 and 22 June 2020	• COVID-19 patients with haematological malignancy (n = 740)	Patients with haematological malignancies are at increased risk of experiencing severe COVID-19 events, such as ICU admission, MV support, or death, compared with non-malignant COVID-19 patients	NHL (30.1%), myelodysplastic syndrome (19.7%), and myeloproliferative neoplasm (15.7%) were the most common haematological malignancies	[215]
China	Jan 13 and Mar 18, 2020	• 205 patients with cancer and laboratory-confirmed SARS-CoV-2 infection and 22 patients (11%) had haematological malignancies	Patients with cancer and COVID-19 who were hospitalized had a high mortality rate	Haematological malignancies	[216]
Spain	March 7, 2020, and April 7, 2020	• Mortality of patients with haematological malignancies compared to non-cancer patients (35.9% vs. 13.2%)	Mortality from COVID-19 is significantly higher in patients with haematological malignancies compared to non-cancer patients	Lymphoma (30%) and MM (30%)	[217]
Italy	March 1, 2020, and April 11, 2020	• 206 patients with COVID-19 and the prevalence of anemia in COVID-19 was 61%	COVID-19 often leads to anemia as a widespread symptom. While anemia may not have a direct impact on mortality, it can significantly affect the well-being of the elderly and vulnerable, thereby reducing their quality of life	Non-malignant	[218]
China	1 December 2019 to 20 March 2020	• 222 confirmed patients including 79 patients with anaemia and 143 patients without anaemia	Anemic COVID-19 patients showed higher rates of comorbidities, more severe inflammatory responses, and organ damage compared to non-anemic controls	Non-malignant	[219]
Italy	May 01 and June 15, 2020	• 860 patients with malignancy were tested, of which 474/860 (55%) had haematological malignancies and 386/860 (45%) had solid tumors	Increased risk of contracting COVID‐19 in patients with haematological malignancy	Neoplasms were lymphomas in 198/860 (23%) cases, breast cancer in 103/860 (12%) cases, MM in 103/860 (12%) cases, acute leukemia in 83/860 (9.5%) cases, and lung cancer in 81/860 (9%) cases	[220]
Japan	Feb-22	• The average (± SD) age of 9 individuals was 74 ± 7 years (ranging from 61 to 85 years), and 6 people (66.7%) were male. All participants had a case of ongoing HM: 3 (33.3%) with myeloproliferative disorder. 6 (66.7%) of the patients had received two vaccines more than half a year ago	Although the Omicron strain can be more serious than previous cases, the mortality rate for hospitalized people with underlying health conditions who are infected with the Omicron strain is still significant	4 (44.4%) with malignant lymphoma, and 2 (22.2%) with MM	[8]

Abbreviations: MM Multiple myeloma, NHL Non-hodgkin’s lymphoma