Recovery rates are not uniform, and more ill patients die faster than well patients recover. #deaths/(#deaths + #recoveries) will overestimate CFR, and #deaths

Recovery rates are not uniform, and more ill patients die faster than well patients recover. #deaths/(#deaths + #recoveries) will overestimate CFR, and #deaths/#cases will underestimate CFR. The final result will be somewhere in the middle, around 1-1.5%, unless the hospital system gets overloaded in the UK.