Predictors of Duration of Hospital Stay in COVID-19 Disease: A Retrospective Study

Abstract

Introduction: A cluster of pneumonia cases were recognised at the end of the year 2019, and later designated as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It was declared as pandemic in early 2020. Coronavirus Disease 2019 (COVID-19) caused considerable morbidity and mortality. Further, it was discovered that presence of co-morbidities like diabetes mellitus, ischaemic heart disease and appearance of cytokine storm caused increased mortality. Aim: To identify co-morbidities and laboratory parameters associated with prolonged hospitalisation in COVID-19 disease. Materials and Methods: This retrospective study was conducted in Department of General Medicine at SDM College of Medical Sciences and Hospital, Shri Dharmasthala Manjunatheshwara University, Dharwad, Karnataka, India (tertiary care hospital). Data between 1st July 2020 to 30th September 2020 was collected, and analysis and interpretation was done from November 2020 to March 2021 from data obtained from medical records. Data of 402 participants was analysed for baseline characteristics like demographic distribution (age and gender), presence of co-morbidities like diabetes mellitus, hypertension, ischaemic heart disease. Patients were divided as per level of oxygen requirements, duration of hospitalisation and usage of remdesivir or steroid or both. Laboratory parameters studied were complete blood count, platelet count, serum sodium, parameters of hyperinflammation like C-reactive Protein (CRP), Lactate dehydrogenase (LDH), ferritin. Markers of COVID-19 associated with high mortality like Neutrophil to Lymphocyte Ratio (NLR) and D-dimer were also taken. Mean hospital stay was associated with all the parameters. Data was analysed by one way Analysis of Variance (ANOVA) and Independent t-test. Results: Maximum patients seen were in the age group of 40-60 years (45.52%). Common co-morbidities observed were diabetes mellitus (48.26%) and hypertension (45.27%). Presence of co-morbidities like diabetes mellitus (p-value=0.0171), hypertension (p-value =0.0238), ischaemic heart disease (p-value=0.0024) was associated with prolonged hospitalisation. Among laboratory markers higher level of parameters of inflammation like NLR >2 (p-value=0.0183), CRP >6 mg/L (p-value=0.004), ferritin >300 ng/mL (p-value=0.05) and indicators of hypercoagulable state {D-dimer >500 ng/mL (p-value=0.0014)} were associated with significantly prolonged stay. patient who received both remdesivir and steroids stayed longer compared to either remdesivir alone or only steroids (p-value=0.0001). Conclusion: State of hyperinflammation and presence of co-morbidity especially uncontrolled diabetes mellitus and usage of steroids were associated with prolonged hospitalisation. Periodic assessment of these patients until recovery may help reducing mortality and morbidity.

Keywords

• coronavirus disease-2019
• cytokine storm
• high neutrophil-lymphocyte ratio
• hyperinflammation
• hyperferritenaemia
• uncontrolled hyperglycaemia