BackgroundThe COVID-19 pandemic seems to have a different picture in Africa; the first case was identified in the continent after it has already caused a significant loss to the rest of the world and the reported number of cases and mortality rate has been low. Understanding the characteristics and outcome of the pandemicin the African setup is therefore crucial.AimTo assess the characteristics and outcome of COVID-19 patients and to identify determinants of the disease outcome among patients admitted to Millennium COVID-19 Care Center in Ethiopia.MethodsA prospective cohort study was conducted among 1345 consecutively admitted RT-PCR confirmed COVID-19 patients from July to September, 2020. Frequency tables, KM plots, median survival times and Log-rank test were used to describe the data and compare survival distribution between groups. Cox proportional hazard survival model was used to identify determinants of time to clinical improvement and the independent variables, where adjusted hazard ratio, P-value and 95% CI for adjusted hazard ratio were used for testing significance and interpretation of results. Binary logistic regression model was used to assess the presence of a statistically significant association between disease outcome and the independent variables, where adjusted odds ratio, P-value and 95% CI for adjusted odds ratio were used for testing significance and interpretation of resultsResultsAmong the study population, 71 (5.3%) died, 72 (5.4%) were transferred and the rest 1202 (89.4%) were clinically improved. The median time to clinical improvement was 14 days. On the multivariable Cox proportional hazard model; temperature (AHR= 1.135, 95% CI= 1.011, 1.274, p-value=0.032), COVID-19 severity (AHR= 0.660, 95% CI= 0.501, 0.869, p-value=0.003), and cough (AHR= 0.705, 95% CI= 0.519, 0.959, p-value=0.026) were found to be significant determinants of time to clinical improvement. On the binary logistic regression, the following factors were found to be significantly associated with disease outcome; SPO2 (AOR= 0.302, 95% CI= 0.193, 0.474, p-value=0.0001), shortness of breath (AOR= 0.354, 95% CI= 0.213, 0.590, p-value=0.0001) and diabetes mellitus (AOR= 0.549, 95% CI= 0.337, 0.894, p-value=0.016).ConclusionsThe average duration of time to clinical improvement was 14 days and 89.4 % of the patients achieved clinical improvement. The mortality rate of the studied population is lower than reports from other countries including those in Africa. Having severe COVID-19 disease severity and presenting with cough were found to be associated with delayed clinical improvement of the disease. On the other hand, being hyperthermic is associated with shorter disease duration (faster time to clinical improvement). In addition, lower oxygen saturation and subjective complaint of shortness of breath and being diabetic were associated with unfavorable disease outcome. Therefore, patients with these factors should be followed cautiously for a better outcome.