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COVID-19 Symptoms: Longitudinal Evolution and Persistence in Outpatient Settings

Our take —

In this brief report from Geneva, Switzerland, at least one-third of non-hospitalized COVID-19 patients reported persistent symptoms at an average of 43 days after diagnosis via telephone interviews. The most common persistent symptoms were fatigue, difficulty breathing, and loss of taste or smell. This study adds to the accumulating evidence base on long-term COVID-19 symptoms, though studies that follow larger groups of people over longer durations are needed to enhance our understanding of the natural history of this disease.

Study design

Case Series

Study population and setting

The authors described longitudinal COVID-19 symptoms among 669 symptomatic ambulatory patients (60% female, mean age 43 years) who were initially diagnosed at a single hospital in Geneva, Switzerland from March 18 to May 15, 2020. Patients who were not hospitalized were referred to ambulatory care centers for remote follow-up. Patients were telephoned every 48 hours for the first two days after diagnosis, then once from 30 to 45 days after diagnosis. Standardized interviews regarding self-reported symptoms were performed at each telephone contact. The authors considered two-day intervals for analysis during the first 10 days of follow-up.

Summary of Main Findings

Of all patients testing positive during the study period, 22% were hospitalized and 703 patients were enrolled in remote follow-up. Of the 669 eligible patients, 25% were healthcare workers and 31% had at least one underlying comorbidity. The number of patients reached during the first 10 days diminished due to hospitalization, patients declining follow-up, and clinical recovery (e.g., 376 of 669 patients [56%] were interviewed 9-10 days after diagnosis). Forty patients (6%) were hospitalized during follow-up. The authors attempted to reach all 669 patients during the day 30-45 interval; 510 patients (76%) were interviewed at a mean of 43 days after diagnosis. During this 30-45 day interval, 32% of the original cohort of 669 patients were reached and reported at least one persistent symptom, while 24% of patients could not be reached. The most commonly reported persistent symptoms were fatigue, dyspnea, and loss of taste or smell.

Study Strengths

A reasonably large sample of outpatients provided information on symptoms at least 4 weeks following COVID-19 diagnosis.


Those enrolled in remote follow-up represented a small proportion (16%) of all non-hospitalized symptomatic patients testing positive for SARS-CoV-2 infection in Geneva during the study period, and may not be representative of the larger target population. For example, included patients may have been more likely to initially experience dyspnea or loss of taste or smell, making them more concerned than other patients about longer-term effects. Detailed information about patient demographics and comorbidities were not reported, making it difficult to apply these data to other patient populations. Loss to follow-up was considerable, so the prevalence of persistent symptoms more than 30 days after diagnosis must be regarded as a lower bound. Finally, symptom prevalence was assessed via self-report, which is subject to possible over-or under-ascertainment.

Value added

This is one of the few studies to date assessing symptoms among non-hospitalized COVID-19 patients, particularly beyond 30 days after symptom onset.

This review was posted on: 22 January 2021