The in-hospital survival of patients suffering from acute pancreatitis (AP) is 95-98%. However, there is growing evidence that patients discharged after AP may be at risk of serious morbidity and mortality. Here, we aimed to investigate the risk, causes, and predictors of the most severe consequence of the post-AP period: mortality.2,613, well-characterized patients from twenty-five centers were collected and followed by the Hungarian Pancreatic Study Group between 2012 and 2021. A general and a hospital-based population was used as the control group.After an AP episode patients have an approximately three-fold higher incidence rate of mortality than the general population (0.0404vs.0.0130 person-years). First-year mortality after discharge was almost double than in-hospital mortality (5.5%vs.3.5%), with 3.0% occurring in the first 90-day period. Age, comorbidities, and severity were the most significant independent risk factors for death following AP. Furthermore, multivariate analysis identified creatinine, glucose, and pleural fluid on admission as independent risk factors associated with post-discharge mortality. In the first 90-day period, cardiac failure and AP-related sepsis were among the main causes of death following discharge, while cancer-related cachexia and non-AP-related infection were the key causes in the later phase.Almost as many patients in our cohort die in the first 90-day period after discharge as during their hospital stay. Evaluation of cardiovascular status, follow-up of local complications, and cachexia-preventing oncological care should be an essential part of post-AP patient care. Future study protocols in AP must include at least a 90-day follow-up period after discharge
