This study estimates the time between onset of symptoms and outcome (death or discharge from hospital) for individuals with COVID-19 infections. Findings provide fatality ratios across the spectrum of COVID-19 disease and demonstrate a strong age-gradient in risk.
A range of case fatality ratio (CFR) estimates for COVID 19 have been produced that differ substantially in magnitude.
Used individual-case data from 44,672 laboratory-confirmed COVID-19 cases from mainland China, this study estimates the time between onset of symptoms and death or discharge from hospital by age. Using data on age stratified severity in a subset of 3,665 cases from China, they also estimated the proportion of infections that will likely require hospitalization.
The mean duration from onset-of-symptoms to death was 17.8 days (95% CI 16.9 to 19.2 days) and from onset-of-symptoms to hospital discharge was 22.6 days (95% CI 21.1 to 24.4 days).
The crude CFR was 3.67% (95% CI 3.56% to 3.80%) in cases from mainland China. The CFR adjusted for demography and under-ascertainment of milder cases in Wuhan relative to the rest of China was 1.38% (95% CI 1.23% to 1.53%) with substantially higher values in older ages.
The CFR from international cases stratified by age (under 60 or 60 and above) were consistent with these estimates from China.
