Longitudinal investigation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in older patients in the province of Palermo (Southern Italy) during the early wave of the pandemic

Abstract

Introduction: Clinical presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in old adults from Southern Italy is little known. This study aims to investigate the mortality risk related to risk factors, therapy and clinical course and to suggest prognostic indicators based on day-to-day follow-up of clinical and laboratory findings.

Material and methods: It was designed as a retrospective longitudinal cohort study of adult SARS-CoV-2 patients admitted at Partinico COVID Hospital in Palermo, Southern Italy. Patients were recruited between 4 March and 25 April and followed up until 31 May 2020, day-to-day until death or hospital discharge. Clinical data, laboratory tests and treatment data were extracted from medical records and epidemiologic information was obtained by clinical history and the medical interview.

Results: Forty-seven patients (median age = 75 IQR: 59.50-86.00) were followed up during a 87 days observation period, accounting for a total of 1,035 person days. At the end of follow-up, 28 (60%) patients were discharged and 19 (40%) died, so that the estimated incidence density rate was 0.018 deaths per day (18 SARS-CoV-2-related deaths per 1,000 patient days). Diabetes (HR = 8.13, 95% CI: 1.91-34.67), chronic kidney failure (HR = 5.86, 95% CI: 1.36-25.21), dementia (HR = 7.84, 95% CI: 1.80-34.20), and neutrophil/lymphocyte ratio > 7 (HR = 10.37, 95% CI: 2.24-48.14) were found as significant prognostic factors.

Conclusions: The joint evaluation of dementia, diabetes, chronic kidney failure and neutrophil/lymphocyte ratio showed an optimal prognostic value already in the first week of follow-up. The day-to-day follow-up provides essential information for clinical monitoring and treatment of the disease in a hospital setting and improves the disease's home management, especially for older patients with frailty.

Keywords: D-dimer; chronic kidney failure; dementia; diabetes; neutrophil/lymphocyte ratio; prognostic factors.

Figure 1

Comparison between survivors and non-survivors in terms of day-to-day mean NLR variation, with horizontal line at NLR = 7 (A) and mean D-dimer variation (B)

Figure 2

Predictive performance of the model: time-dependent ROC curves and predicted AUCs at times 3 (A), 5 (B), 7 (C), 14 (D), 21 (E), 28 (F)