Background: Coronavirus disease (COVID-19) has imposed unprecedented stressors on South Africa (SA)'s healthcare system. Superimposed on the country's quadruple burden of disease, pandemic-related care further exposes existing inequities. Some of these inequities are specific to hospital-based inpatient services, such as the geographical maldistribution of hospital beds, lack of oxygen supplies and assisted ventilation, and scarcity of trained healthcare workers. Certain high-risk groups, such as individuals with cardiometabolic comorbidity, are likely to develop severe COVID-19 disease requiring hospitalisation with potential for a prolonged length of stay (LoS). It may be helpful for health authorities to identify those at risk for prolonged LoS to facilitate appropriate health systems planning.
Objectives: To identify hospital admission laboratory parameters associated with a hospital stay >14 days in patients with COVID-19 pneumonia.
Methods: A retrospective observational study design was used. Laboratory data were obtained from an SA private laboratory for 642 inpatients with suspected or confirmed COVID-19 pneumonia, comprising 7 months of admission laboratory data from six private hospitals in Johannesburg, Gauteng Province.
Results: Of 642 hospital admissions for pneumonia, 497 were confirmed to have COVID-19 infection (reverse transcription-polymerase chain reaction test positive). In the COVID-19-positive group, hospital LoS was prolonged in 35.4% of admissions. Univariate analysis demonstrated an association with the following risk factors for prolonged LoS: older age; male sex; high serum creatinine, sodium (Na), chloride, potassium and urea levels and low estimated glomerular filtration rate; raised white blood cell count, lymphopenia, neutrophilia and an elevated neutrophil-to-lymphocyte ratio (NLR); and elevated levels of D-dimers, interleukin-6 (IL-6), and procalcitonin (PCT). The strongest univariate associations (relative risk (RR) ≥2.0) with a hospital stay >14 days were high Na levels, NRL >18, high PCT levels and IL-6 >40 pg/mL. On multivariable analysis, the following factors remained significantly associated with prolonged LoS: older age (RR 1.015 per year of age; 95% confidence interval (CI) 1.005 - 1.024); hypernatraemia (RR 1.80; 95% CI 1.25 - 2.60); hyperkalaemia (RR 1.61; 95% CI 1.18 - 2.20); and neutrophilia (RR 1.47; 95% CI 1.15 - 1.88).
Conclusions: COVID-19 pandemic preparedness requires hospital-based inpatient care to be prioritised in resource-limited settings, and availability of beds and prompt admissions are essential to ensure good clinical outcomes. In this study of COVID-19 patients admitted with pneumonia, multivariable analysis showed older age, hypernatraemia, hyperkalaemia and neutrophilia to be associated with LoS >14 days. This may assist with healthcare systems planning.