ABSTRACT
COVID-19 is an acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first detected in China (December 2019) but now widespread. The aim of this study was to investigate the main haematological changes in severe cases of COVID-19 and if full blood count results at admission can be used to determine in-hospital mortality risk. This retrospective observational study included laboratory results of confirmed cases of hospitalised patients with SARS-CoV2 infection in Jersey between March and December 2020 (subject to inclusion criteria), split into two subgroups based on outcome (non-survivors versus survivors). Statistically significant changes between groups were defined by probability ( p ) <0.05, using t -test, Mann-Whitney test, or X2 /Fisher exact test, as appropriate. Multivariate and univariate logistic models were used to determine risk factors for in-hospital mortality. A total of 81 cases (out of 113 available cases) were included in this study: median age: 75 years;48 patients were men (59.3%);27 non-survivors (33.3%) and 18 (22%) required intensive care. Non-survivors showed the following statistically significant changes compared to survivors: non-survivors were older (median age: 82 vs. 74 years, p = 0.003);70.4% presented with marked lymphopenia (median: 0.63 vs. 0.99 × 109 /l, p = 0.025), 55.6% with raised creatinine (median: 103.0 μmol/l, p = 0.024), 40.7% with elevated white blood cells (WBC) (median: 9.5 vs. 7.3 × 109 /l, p = 0.042) and 14.8% with lower mean cell haemoglobin concentration (MCHC) (32.99 vs. 33.79 g/dl, p = 0.030). Univariate analysis showed age ≥ 82 years was significantly associated with death (odds ratio [OR] = 4.210, p = 0.005). Multivariate logistic analysis identified the following risk factors for in-hospital mortality: lymphocytes <0.85 × 109 /l (OR = 6.694, p = 0.004), WBC >9.5 × 109 /l (OR = 4.855, p = 0.015) and creatinine >100 μmol/l (OR = 3.280, p = 0.049). Full blood count results on hospital admission can be used to identify COVID-19 patients with higher mortality risk. Inhospital mortality risk was shown to be 6.7 times higher in patients presenting with a lymphocyte count <0.85 × 109 /l, 4.9 times higher in patients presenting with a WBC >9.5 × 109 /l and 3.3 times higher for those presenting with creatinine levels over 100 μmol/l. Age ≥ 82 years was significantly associated with death. Additionally, this study suggests male gender is a risk factor for hospital admission in COVID-19.