Abstract
BACKGROUND: Long COVID remains a significant public health concern. This study investigated risk factors for long COVID in outpatient settings. METHODS: A US-based prospective survey study (clinicaltrials.gov NCT05160636) was conducted in 2022 and replicated in 2023. Symptomatic adults testing positive for SARS-CoV-2 at CVS Pharmacies were recruited. CDC-based long COVID symptoms were collected at Week 4, Month 3, and Month 6 following SARS-CoV-2 testing. Logistic regression was used to develop a predictive model for long COVID using data from the 2022 cohort. The model was validated with data from the 2023 cohort. Model performance was evaluated with c-statistics. RESULTS: Patients characteristics were generally similar between the 2022 (N = 328) and 2023 (N = 505) cohorts. The prevalence of long COVID defined as ≥3 symptoms at Month 6 was 35.0% and 18.2%, respectively. The risk factors associated with long COVID were older age, female sex, lack of up-to-date vaccination, number of acute symptoms on the day of SARS-CoV-2 testing, increase in symptoms at Week 1, underlying comorbidities and asthma/chronic lung disease. The c-statistic was 0.79, denoting good predictive power. CONCLUSIONS: A predictive model for long COVID was developed for an outpatient setting. This research could help differentiate at-risk groups and target interventions.