text: Recognition of Long COVID 19 Patients in a Canadian Tertiary Hospital Setting A Retrospective Analysis of Their Clinical and Laboratory Characteristics A proportion of patients with COVID 19 have symptoms past the acute disease phase which may affect quality of life It is important for clinicians to be aware of this long COVID 19 syndrome to better diagnose treat and prevent it We reviewed clinical and laboratory characteristics of a COVID 19 cohort in a Toronto Ontario tertiary care center Demographic clinical and laboratory data were collected and patients were classified as long COVID 19 or non long COVID 19 using consensus criteria Of 397 patients who tested positive for COVID 19 223 met inclusion criteria and 62 27 had long COVID 19 These patients had a similar age distribution compared to non long COVID 19 patients overall but were younger in the admitted long COVID 19 group The long COVID 19 group had more inpatients compared to the non long COVID 19 group 39 vs 25 and more frequent supplemental oxygen or mechanical ventilation use However long COVID 19 patients did not differ by duration of mechanical ventilation length of stay comorbidities or values of common laboratory tests ordered The most frequent symptoms associated with long COVID 19 were fatigue and weakness as reported most commonly by the infectious disease respirology and cardiology disciplines In conclusion by retrospective chart review 27 of COVID 19 patients presenting to a tertiary care center in Toronto Canada were found to meet criteria for long COVID 19 Past medical history and routine laboratory testing at presentation did not predict for long COVID 19 development 