Related Articles Comparison of the characteristics morbidity and mortality of COVID 19 and seasonal influenza a nationwide population based retrospective cohort study Lancet Respir Med 2020 Dec 17 Authors Piroth L Cottenet J Mariet AS Bonniaud P Blot M Tubert Bitter P Quantin C Abstract BACKGROUND To date influenza epidemics have been considered suitable for use as a model for the COVID 19 epidemic given that they are respiratory diseases with similar modes of transmission However data directly comparing the two diseases are scarce METHODS We did a nationwide retrospective cohort study using the French national administrative database PMSI which includes discharge summaries for all hospital admissions in France All patients hospitalised for COVID 19 from March 1 to April 30 2020 and all patients hospitalised for influenza between Dec 1 2018 and Feb 28 2019 were included The diagnosis of COVID 19 International Classification of Diseases 10th edition codes U07 10 U07 11 U07 12 U07 14 or U07 15 or influenza J09 J10 or J11 comprised primary related or associated diagnosis Comparisons of risk factors clinical characteristics and outcomes between patients hospitalised for COVID 19 and influenza were done with data also stratified by age group FINDINGS 89 530 patients with COVID 19 and 45 819 patients with influenza were hospitalised in France during the respective study periods The median age of patients was 68 years IQR 52 82 for COVID 19 and 71 years 34 84 for influenza Patients with COVID 19 were more frequently obese or overweight and more frequently had diabetes hypertension and dyslipidaemia than patients with influenza whereas those with influenza more frequently had heart failure chronic respiratory disease cirrhosis and deficiency anaemia Patients admitted to hospital with COVID 19 more frequently developed acute respiratory failure pulmonary embolism septic shock or haemorrhagic stroke than patients with influenza but less frequently developed myocardial infarction or atrial fibrillation In hospital mortality was higher in patients with COVID 19 than in patients with influenza 15 104 16 9 of 89 530 vs 2640 5 8 of 45 819 with a relative risk of death of 2 9 95 CI 2 8 3 0 and an age standardised mortality ratio of 2 82 Of the patients hospitalised the proportion of paediatric patients 18 years was smaller for COVID 19 than for influenza 1227 1 4 vs 8942 19 5 but a larger proportion of patients younger than 5 years needed intensive care support for COVID 19 than for influenza 14 2 3 of 613 vs 65 0 9 of 6973 In adolescents 11 17 years the in hospital mortality was ten times higher for COVID 19 than for influenza five 1 1 of 458 vs one 0 1 of 804 and patients with COVID 19 were more frequently obese or overweight INTERPRETATION The presentation of patients with COVID 19 and seasonal influenza requiring hospitalisation differs considerably Severe acute respiratory syndrome coronavirus 2 is likely to have a higher potential for respiratory pathogenicity leading to more respiratory complications and to higher mortality In children although the rate of hospitalisation for COVID 19 appears to be lower than for influenza in hospital mortality is higher however low patient numbers limit this finding These findings highlight the importance of appropriate preventive measures for COVID 19 as well as the need for a specific vaccine and treatment FUNDING French National Research Agency PMID 33341155 PubMed as supplied by publisher