Vital Sign Abnormalities on Discharge Do Not Predict 30-Day Readmission

Hospital readmissions are common and expensive. Risk factors for hospital readmission may include vital sign abnormalities (VSA) at the time of discharge. The study aimed to validate VSA at the time of discharge as a useful predictor of hospital readmission within 30 days of discharge. VSA was compared to the validated HOSPITAL score and LACE index readmission risk prediction models.

All adult medical patients discharged from internal medicine hospitalist service were studied retrospectively. Variables such as age, gender, diagnoses, vital signs at discharge, 30-day hospital readmission, and components for the HOSPITAL score and LACE index were extracted from the electronic health record for analysis.

A 507-bed university-affiliated tertiary care center.

During the 2-year study period, a cohort of 1,916 discharges for the hospitalist service were evaluated. The final analysis was based on the data from 1,781 hospital discharges that met the inclusion criteria.

VSA was found in 13% of the study population. Only one abnormal vital sign was present in a higher proportion readmitted to the hospital within 30 days of discharge. No discharges had three 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 VSA (C statistic of 0.52, P = 0.318) indicated that VSA at time of discharge was not a useful predictor of hospital readmission within 30 days of discharge.

Our study indicated that VSA at the time of discharge is not a useful predictor of 30-day hospital readmission at a university-affiliated teaching hospital. The more complex and validated HOSPITAL score and LACE index were useful predictors of hospital readmission in this patient population.