Predictors of Length of Hospital Stay in Patients with COVID-19: A Retrospective Study

Introduction: Known independent predictors of extended Length Of Stay (LOS) in Coronavirus Disease 2019 (COVID-19) included older age, chronic kidney disease, elevated maximum temperature, and low minimum oxygen saturation. Additional known predictors of prolonged hospitalisation included male sex, chronic obstructive pulmonary disease, hypertension, and diabetes. Elevated levels of C-Reactive Protein (CRP), creatinine, and ferritin are proven determinants of hospitalisation and LOS. Determining predictors of LOS will aid in triaging and management of COVID-19 patients.

Aim: To assess the clinical, biochemical and radiological profile of admitted COVID-19 patients and determine the predictors of prolonged length of stay at hospital.

Materials and Methods: It was a retrospective, cross-sectional observational, record-based study included hospital records of 544 confirmed COVID-19 patients, above age of 18 years admitted at Bharati Vidyapeeth Medical College and Hospital, Pune, Maharashtra, India, during February 2021 to June 2021. Possible determinants of LOS were studied including their demographic, epidemiological, clinical and radiological characteristics. The patients were divided into two groups as per median LOS i.e, group I with LOS <10 days (n=277) and group II with LOS ≥10 days (n=267). Statistical analysis was done using Chi-square test, proportion test, Z test, Mann-Whitney U test, regression analysis by Statistical Package for the Social Sciences (SPSS) software version 23.0.

Results: Mean age in group I and II was 47.83±16.34 years and 53.21±15.63 years (p-value <0.0001), respectively. The fatigue was significantly more in group II than group I (p-value=0.018). Diabetes mellitus was more (p-value=0.026) and severity of illness (p-value <0.0001) was significantly higher in group II than group I. In univariate analysis, mean Neutrophil/Lymphocyte ratio (p-value <0.0001), serum LDH (p-value <0.018), blood urea level (p-value <0.0001), random blood sugar (p-value=0.003), glycated haemoglobin (HbA1c) (p-value=0.072) and serum creatinine (p-value=0.41) were significantly more in group II. Median CRP (p-value <0.0001), D-dimer (p-value <0.0001), serum ferritin (p-value <0.0001), procalcitonin (p-value <0.0001), Serum Glutamic Oxaloacetic Transaminase (SGOT) (p-value=0.002) was significantly higher in group II. Lung involvement {chest radiograph or High-Resolution Computed Tomography (HRCT) chest} was significantly (p-value <0.0001) more in group II.

Conclusion: Fatigue, older age, diabetes mellitus, severity of illness, mean neutrophil/lymphocyte ratio, CRP, D-dimer, serum ferritin, serum Lactate Dehydrogenase (LDH), procalcitonin, blood urea, SGOT were associated with prolonged LOS among hospitalised COVID-19 patients.