Clinical and Safety Outcomes of Patients Admitted to Different Specialty Wards: The Prospective, Multi-center, Controlled SISIFO Study

Objectives: Patients’ admission to different specialty wards (the so-called “outliers”) due to a hospital bed shortage may significantly reduce the quality and safety of clinical care. However, data on clinical outcomes are limited, heterogeneous, and mainly retrospective. For this reason, we performed a prospective controlled study, the Survival and Safety Issues for Medical Outliers (SISIFO) study. Methods: We conducted the SISIFO study, a prospective, multicenter, controlled study to primarily evaluate clinical and safety outcomes in outliers from October 2018 to March 2020. Results: Thirty-seven Italian Internal Medicine Units enrolled 2056 medically ill patients, 988 outliers, and 1068 controls. Overall, the median length of hospital stay was 10 days [interquartile range (IQR) 7-15]. The median stay in the different specialty wards was 2 days (IQR 2-4). The in-hospital mortality of outliers was significantly higher than that of controls ( OR =2.1, 95% CI: 1.3-3.3) at multivariate analysis. Among outliers, modified early warning score (MEWS) >3, reduced mobility, and dysphagia at baseline were significantly associated with a higher risk of in-hospital death. No significant differences between “outliers” and controls were observed for secondary outcomes, including postdischarge 90-day mortality and readmission rate, requests for diagnostic tests, or specialist consultations. In-hospital adverse events presented some noteworthy findings. Conclusions: Our study suggests a significant increase in in-hospital mortality associated with admission to different specialty wards. Future studies should investigate the specific reasons for this finding.