Introduction
Hospital readmissions are common, expensive, and the target of the ambitious Medicare Hospital Readmission Reduction Program (HRRP). Risk factors for hospital readmission and more complex and validated risk assessment tools such as the HOSPITAL score and LACE index can be used to identify patients at high risk of hospital readmission. This study aims to evaluate the utility vital sign instability at the time of discharge for predicting hospital readmission within 30 days in a moderate sized university affiliated hospital in the Midwest of the United States.
Materials and Methods
All adult medical patients discharged from the SIU Medicine Hospitalist service from Memorial Medical Center (MMC) from January 1, 2015 to January 1, 2017, were studied retrospectively to determine if vital sign instability at the time of discharge was a significant predictor of hospital readmission within 30 days. Vital sign instability was compared to the established HOSPTIAL score and LACE index tools for readmission risk assessment.
Results
During the study period, 1,916 discharges were recorded for the hospitalist service. The analysis includes data for the 1,781 discharges that met inclusion criteria. The study population was 47% female, had an average age of 63 years, and spent 7.9 days in the hospital. Of these individuals, 456 (26%) were readmitted to the same hospital within 30 days. Vital sign instability was found 13% of the study population. The frequency of discharges with any vital sign instability was slightly higher (15% vs. 12%, p = 0.084) in the group that was readmitted to the same hospital within 30 days. Only one unstable vital sign was present in a higher proportion of the study population that was readmitted to the hospital within 30 days of discharge (14.5% vs. 10.6%, p = 0.024). Two unstable vital signs were more common in the group not readmitted within 30 days of discharge (1.4% vs. 0.06%, p = 0.196). No discharges had 3 or more unstable vital signs. Receiver operating characteristic (ROC) comparisons of the HOSPITAL score (C statistic of 0.67, p < 0.001), LACE index (C statistic of 0.61, p < 0.001), and vital sign instability (C statistic of 0.52, p = 0.318) indicated that vital sign instability at time of discharge was not a useful predictor of hospital readmission within 30 days of discharge.
Discussion
This single center retrospective study indicates that vital sign instability at the time of discharge is not a significant predictor of hospital readmission within 30 days at a medium sized university affiliated teaching hospital. The performance of the more complex HOSPITAL score and LACE index was good in the study population.
Conclusions
The presence of vital sign instability does not appear to be a useful tool to identify patients at high risk of hospital readmission within 30 days in a moderate sized university affiliated teaching hospital.