Time between Symptom Onset, Hospitalisation and Recovery or Death: Statistical Analysis of Belgian COVID-19 Patients

TLDR

COVID‑19 outbreak patterns differ between the general population and nursing home residents. The study examines symptom‑onset to diagnosis/hospitalization intervals and hospital length of stay across patient groups. Data from 14,618 hospitalized Belgian patients were analyzed using interval‑censoring and right‑truncation techniques to estimate event‑time distributions. Median symptom‑onset to hospitalization ranged 3–10.4 days, longer in 20–60 year olds and nursing‑home residents; hospital length of stay also 3–10.4 days, increasing with age, shorter for nursing‑home survivors but longer to death, and overall decreased during the first wave.

Abstract

There are different patterns in the COVID-19 outbreak in the general population and amongst nursing home patients. We investigate the time from symptom onset to diagnosis and hospitalization or the length of stay (LoS) in the hospital, and whether there are differences in the population. Sciensano collected information on 14,618 hospitalized patients with COVID-19 admissions from 114 Belgian hospitals between 14 March and 12 June 2020. The distributions of different event times for different patient groups are estimated accounting for interval censoring and right truncation of the time intervals. The time between symptom onset and hospitalization or diagnosis are similar, with median length between symptom onset and hospitalization ranging between 3 and 10.4 days, depending on the age of the patient (longest delay in age group 20–60 years) and whether or not the patient lives in a nursing home (additional 2 days for patients from nursing home). The median LoS in hospital varies between 3 and 10.4 days, with the LoS increasing with age. The hospital LoS for patients that recover is shorter for patients living in a nursing home, but the time to death is longer for these patients. Over the course of the first wave, the LoS has decreased.