Proposed integrative model for post-COVID symptoms.

BACKGROUND AND AIMS: To propose an integrative model for post-COVID symptoms by considering the absence/presence of previous symptomatology. METHODS: We searched different databases for original articles and reviews on post-COVID symptoms. RESULTS: The first consideration is to define which symptoms are of "new-onset" (symptoms never experienced by a patient before COVID-19 and experienced the first time after) and which symptoms are "exacerbated" (symptoms experienced by a patient prior to COVID-19 but aggravated later) after infection. The second consideration includes defining "persistent" (symptoms experienced at the acute phase and continuing after without remission period) and "delayed-onset" (symptoms not experienced at the acute phase of the infection but appearing after a "latency period"). This model integrates predisposing individual factors, biological factors associated to the severity of disease, hospitalization/treatment factors, and outbreak surrounding factors which may promote post-COVID. CONCLUSION: Since current literature on post-COVID is heterogeneous, this integrative model could help to a better characterization of long-COVID.