Patients admitted on weekends have higher in-hospital mortality than those admitted on weekdays: Analysis of national inpatient sample.

Introduction: Since the 1999 Institute of Medicine report, hospitals have implemented a myriad of measures to protect patients from medical errors. At this point, looking beyond errors may bring additional safety benefits. This study aims to analyze predictors of in-hospital death regardless of underlying diagnoses in an effort to identify additional targets for improvement. Methods: We performed a retrospective study of hospitalizations from the 2016-2019 National Inpatient Sample (NIS) database. Logistic regression analyses were used to calculate adjusted odds ratios (OR) for variables associated with in-hospital death. Results: There were 121,026,484 adult hospital discharges in the database. Multivariable analysis showed the following variables were associated with higher in-hospital death: Age (OR, 1.04), Charlson Comorbidity Index (OR, 1.23), male (OR, 1.16), income Q1 (OR, 1.12), income Q2 (OR, 1.07), west region (OR, 1.07), non-elective admission (OR, 2.01), urban hospital location (OR, 1.17), and weekend admission (OR, 1.14). Percentage of deaths for weekend versus weekday admissions was 2.7% versus 2.1%. Fewer procedures (ICD-10-PCS) were done in first 24 hours of weekend admissions when compared to weekday admissions (34.8% vs 46.8%; p<0.001). Only 524,295 in-hospital deaths were expected for weekend admissions but 673,085 were observed. Conclusion: Weekend hospital admissions were associated with higher adjusted mortality and a lower rate of procedures when compared to weekday admissions. Further studies should be done to further clarify and confirm if additional staffing and procedural availability on weekends could improve hospital outcomes.