Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) wrote:
As of 20 February, 2114 of the 55,924 laboratory confirmed cases have died (crude fatality ratio, CFR2 3.8%) (note: at least some of whom were identified using a case definition that included pulmonary disease). The overall CFR varies by location and intensity of transmission (i.e. 5.8% in Wuhan vs. 0.7% in other areas in China). In China, the overall CFR was higher in the early stages of the outbreak (17.3% for cases with symptom onset from 1- 10 January) and has reduced over time to 0.7% for patients with symptom onset after 1 February (Figure 4). The Joint Mission noted that the standard of care has evolved over the course of the outbreak.
Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)Note in this WHO report that the CFR (mortality rate) decreased over time and the standard of care increased over time. In other words, the mortality rate can vary with the health care standards (as well as demographics of the population, ie age) in each region. This means generalized data from one region should only be used as a guide for other regions if there are differences in contributing factors like age, health status, quality of available health care, etc.