Symptoms Experienced at the Acute Phase of SARS-CoV-2 Infection as Risk Factor of Long-term Post-COVID Symptoms: The LONG-COVID-EXP-CM Multicenter Study

OBJECTIVE: This multicenter study investigated clinical risk factors associated with the number of long-term symptoms after COVID. METHODS: Clinical features, symptoms at hospital admission, hospitalization data, and the number of symptoms after COVID was systematically assessed for patients who recovered from COVID-19 in 4 hospitals in Madrid (Spain) from February 20 to May 31, 2020. RESULTS: Overall, 1,969 patients (46.5% women, age: 61, SD: 16 years) were randomly assessed 8.4 months (SD 1.5) after hospital discharge. Female gender (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.57-2.10), number of morbidities (OR 1.182, 95% CI 1.08-1.29), number of symptoms at hospital admission (OR 1.309, 95% CI 1.15-1.49) and days at the hospital (OR 1.01, 95% CI 1.007-1.017) were associated (all, p <0.001) with more long-term symptoms after COVID. Further, vomiting (OR 1.78, 95% CI 1.26-2.52), throat pain (OR 1.36, 95% CI 1.02-1.81), diarrhea (OR 1.51, 95% CI 1.25-1.82), dyspnea (OR 1.20, 95% CI 1.01-1.41), or headache (OR 1.50, 95% CI 1.28-1.75) as symptoms at hospital admission were also associated (all, p <0.01) with a higher number of symptoms after COVID. CONCLUSION: This multicenter study found that a higher number of symptoms at hospital admission were the most relevant risk factor for developing more symptoms after COVID, supporting the assumption that a higher symptom load at the acute phase is associated with a greater likelihood of long-term symptoms after COVID.