We have data on the follow-up of 260 Covid’19 patients at major hospital in Madagascar. According to specialists, the patient’s daily oxygen saturation and requirement allow us to characterize the form of the patient’s case in free different states: mild form, moderate form, severe form. We propose a semi-Markovian model with five states (Mild form, Moderate form, Sever form, Cured and Deceased) to analyze the time scales of recovery and death as well as the probability of recovery and death as a function of patient status. The model was also used to measure the dynamic reliability of care up to hospital discharge, i.e. the probability of not being severely ill as a function of hospitalization time.