Risk factors related to the occurrence of post-COVID-19 Syndrome: a systematic review

Background: Post-COVID-19 Syndrome is characterized by a set of signs and symptoms that appear after the acute phase, persist for more than 12 weeks, and cannot be explained by another diagnosis. This systematic review aimed to identify the main risk factors associated with Post-COVID-19 Syndrome and their relationship with disease severity regarding the persistence of signs and symptoms that, alone or combined, characterize the syndrome. Methods: Seventy-three articles published between 2021 and 2023 were selected based on Joanna Briggs Institute manuals and guidelines. Data collection occurred from March 2019 to April 2023 in the databases PubMed (MEDLINE), LILACS, Scopus, EMBASE, Web of Science, Google Scholar, LIVIVO, and ProQuest. Cross-sectional, case-control, and cohort studies in English, Portuguese, or Spanish were included. Results: Fatigue was the most reported symptom (39.42%), followed by a reduced or absent sense of smell (32.87%). Dyspnea (28.56%), persistent cough (28.56%), headache (24.65%), loss of taste (23.28%), sleep disturbances (20.54%), and depression (20.54%) were also frequent. The most associated comorbidities were diabetes mellitus (72.60%), systemic arterial hypertension (61.64%), cardiovascular disease (45.20%), and cancer (35.61%). Conclusion: Risk factors for Post-COVID-19 Syndrome are multifactorial and linked to pre-existing clinical conditions, with emphasis on diabetes, hypertension, and cardiovascular disease.