Age differences in clinical features and outcomes in patients with COVID-19, Jiangsu, China: a retrospective, multicentre cohort study

OBJECTIVES: To determine the age-specific clinical presentations and incidence of adverse outcomes among patients with COVID-19 in Jiangsu, China. DESIGN AND SETTING: Retrospective, multicentre cohort study performed at 24 hospitals in Jiangsu, China. PARTICIPANTS: 625 patients with COVID-19 enrolled between 10 January and 15 March 2020. RESULTS: Of the 625 patients (median age, 46 years; 329 (52.6%) men), 37 (5.9%) were children (18 years or younger), 261 (41.8%) young adults (19–44 years), 248 (39.7%) middle-aged adults (45–64 years) and 79 (12.6%) elderly adults (65 years or older). The incidence of hypertension, coronary heart disease, chronic obstructive pulmonary disease and diabetes comorbidities increased with age (trend test, p<0.0001, p=0.0003, p<0.0001 and p<0.0001, respectively). Fever, cough and shortness of breath occurred more commonly among older patients, especially the elderly, compared with children (χ(2) test, p=0.0008, 0.0146 and 0.0282, respectively). The quadrant score and pulmonary opacity score increased with age (trend test, both p<0.0001). Older patients had many significantly different laboratory parameters from younger patients. Elderly patients had the highest proportion of severe or critically-ill cases (33.0%, χ(2) test p<0.0001), intensive care unit use (35.4%, χ(2) test p<0.0001), respiratory failure (31.6%, χ(2) test p<0.0001) and the longest hospital stay (median 21 days, Kruskal–Wallis test p<0.0001). CONCLUSIONS: Elderly (≥65 years) patients with COVID-19 had the highest risk of severe or critical illness, intensive care use, respiratory failure and the longest hospital stay, which may be due partly to their having a higher incidence of comorbidities and poor immune responses to COVID-19.