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.
ABSTRACT
COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has been associated with over 5 million deaths worldwide since December 2019. Red cell distribution width (RDW) is a routine full blood count parameter that reflects the level of change in size between red cells (anisocytosis) and has been widely researched as an independent predictor of mortality in different hospital settings, including critically ill patients with sepsis. This study aims to investigate if RDW results on admission may be used as a prognostic marker in patients with acute COVID-19 infection. This retrospective study included 81 hospitalised patients with COVID-19 at the General Hospital in Jersey (Channel Islands, UK), subject to inclusion criteria. Differences between groups were calculated using the t test if data were normally distributed, otherwise the Mann-Whitney test was used. p < 0.05 was considered significant for all tests. Area under curve (AUC) and the 95% confidence interval (CI) were determined to establish optimal cut-off point that maximised sensitivity and specificity to predict death by the Youden's index. Logistic regression was then used to determine the odds of in-hospital mortality. Non-survivors were found to be significantly older (median age: 82 years;overall range: 50-94 vs. 74 years;overall range: 28-92 in survivors;p = 0.003) and presented with higher RDW when compared with survivors (14.1 vs. 13.4;p = 0.028). A total of 63 patients (78%) received ward-based care, while 18 patients (22%) required intensive care. Men accounted for most deaths (males: 16 deaths, 59.3% vs. females: 11 deaths, 40.7%), although the mortality rate in males and females was undistinguishable (males: 33.3% vs. females: 33.3%). Multivariate logistic analysis demonstrated that RDW >14% on admission was associated with a 5-fold increased mortality risk in hospitalised patients with COVID-19 (OR = 5.335 [95% CI 1.524-18.674];p = 0.009). This association was shown to be independent of age and other potential confounders such as lymphocyte count, white cells, or creatinine levels. This study confirms the prognostic potential of RDW in hospitalised patients with COVID-19. Identifying patients with higher risk of in-hospital mortality may enable prioritisation of resources and targeted treatments, which could ultimately improve outcomes.