Insights into the Risk Factors and Outcomes of Post-COVID-19 Syndrome—Results from a Retrospective, Cross-Sectional Study in Romania

Post-Coronavirus Disease 2019 (post-COVID-19) syndrome represents a cluster of persistent symptoms following Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection that can severely affect quality of life. The pathogenic mechanisms and epidemiology in different regions are still under evaluation. To assess the outcomes of post-COVID-19 syndrome, we performed a questionnaire-based, cross-sectional study in previously infected individuals. Out of 549 respondents, (male:female ratio: 0.32), 29.5% had persistent symptoms at 3 months, 23.5% had persistent symptoms at 6 months, and 18.3% had persistent symptoms at 12 months after the initial infection. The most common symptoms included fatigue (8.7%), sleep disturbances (7.1%), and cognitive impairment (6.4%). The risk of developing post-COVID-19 syndrome increased for those with more symptoms in the acute phase (OR 4.24, <i>p</i> < 0.001) and those experiencing reinfections (OR 2.405, <i>p</i> < 0.001), while SARS-CoV-2 vaccination halved the risk (OR = 0.489, <i>p</i> = 0.004). Individuals with post-COVID-19 syndrome had a 5.7-fold higher risk of being diagnosed with a new chronic condition, with 44% reporting cardiovascular disease, and a 6.8-fold higher likelihood of needing medical care or leave. Affected individuals reported significant impairments in mobility, pain/discomfort, and anxiety/depression, with 20.7% needing to adjust their work schedules. Overall, patients with post-COVID-19 syndrome require ongoing monitoring and rehabilitation, and further socio-economic impact studies are needed.