Tracking Survivors With Long COVID: Method, Implementation, and Results of an Observational Study.

While the coronavirus disease 2019 (COVID-19) pandemic has declined, many survivors continue to suffer debilitating symptoms, such as fatigue, pain, and foggy thoughts. Sustained COVID-19 symptoms, or Long COVID, challenge health care resources and economic recovery. This article describes the methodology, implementation, and results of an observational study investigating how time since diagnosis may affect lingering symptoms among the adult COVID-19 population. The descriptive distribution and overall symptoms experience by individuals' characteristics were examined. Random samples from two patient cohorts (n = 147 in 2020-2021 and n = 137 in 2021-2022) were recruited from a COVID-19 patient registry in mid-Michigan. Samples were drawn from a pool of patients ≥ 3 months following their COVID-19 diagnosis. Overall symptoms experience (number, severity, interference) was self-reported using a comprehensive symptom inventory. The findings showed that 66% of the 2020-2021 cohort and 47% of the 2021-2022 cohort reported ≥ 1 lingering symptom with an average of 11.2 (±3.0) and 8.9 (±3.3) months, respectively, after COVID-19 diagnosis. Females reported significantly more symptoms (p = 0.018), higher symptom severity (p = 0.008) and interference (p = 0.007) compared to males. Compared to patients admitted to emergency departments, outpatients reported significantly lower symptom severity (p = 0.020) and less symptom interference (p = 0.018). Our analyses showed that a moderate proportion (43%) of adults remained symptomatic nearly a year after COVID-19 infection and time since diagnosis did not affect symptom experience in either cohort. Female sex and admission setting are important factors to consider for managing and studying Long COVID.