Peer Review Report For: Prevalence and Predictors of Long COVID During the Omicron Variant Dominant Epidemic at 3 and 6 Months in Thailand [version 1; peer review: 1 approved, 1 approved with reservations]

Background Long Covid is defined as conditions that continue or develop after acute COVID-19 infection more than 3 months. This study aimed to analyze the point prevalence and predictors of long Covid in the Omicron variant dominant epidemic at 3 and 6 months in Thailand. Methods Prospective cohort study on the COVID-19 cohort at Thammasat University Hospital (TUH) and Thammasat Field Hospital (TFH) during the Omicron variant dominant epidemic was performed. The phone interview for long Covid symptoms was performed among 1,388 patients at 3 months and 917 patients at 6 months after the infection. Clinical characteristics of all participants were retrieved from the database of the hospital. Results The point prevalence of long Covid was 52.59% at 3 months and 28.57% at 6 months. The most prevalent symptom group at both time points was fatigue and weakness, affecting 31.70% of patients at 3 months and 15.81% at 6 months. Three significant predictors of long Covid were identified at both 3 and 6 months: severe-to-critical illness during the acute phase, female sex, and healthcare worker occupation. The adjusted odds ratios (aOR) for severe-to-critical illness were 4.50 [95% CI, 1.59–12.75] at 3 months and 9.15 [95% CI, 1.35–62.10] at 6 months. Female sex was associated with aORs of 2.04 [95% CI, 1.61–2.58] at 3 months and 2.41 [95% CI, 1.71–3.34] at 6 months. Healthcare workers had aORs of 1.96 [95% CI, 1.39–2.78] at 3 months and 3.12 [95% CI, 1.85–5.27] at 6 months. Obesity was a significant predictor of long Covid only at 3 months. Conclusions The prevalence of long Covid remains substantial following the Omicron variant-dominant epidemic. Key predictors of long Covid at both 3 and 6 months include severe-to-critical illness during the acute phase, female sex, and healthcare worker occupation.