Rothman Index as a Predictor of 30-Day Hospital Readmission

Introduction: The Centers for Medicare and Medicaid services financially penalize hospitals for elevated 30-day readmission rates. Identifying patients at high risk for short-term readmission would allow health systems to strategically allocate resources to this vulnerable population. The objective of this study was to determine whether there was a difference in mean Rothman Index value for patients readmitted to the hospital within 30 days of index stay versus patients not readmitted in order to evaluate the Rothman Index’s utility as a predictive tool. Materials and Methods: Data from 100 subjects from a single academic medical center, with a balanced number of readmit (n=50, mean age 68.9 years, 54% female) and non-readmits (n=50, 46% female, mean age 70.9 years), was collected. Results: Non-readmits demonstrated significantly higher mean Rothman Index values (70.94 ± 1.3) compared to patients readmitted within 30 days (mean Rothman Index of 61.68 ± 1.6) at (P< .001; 95% CI, 5.10 to 13.41). Age (95% CI, -0.052 to 0.006; P= .12), gender (95% CI, -0.949 to 0.948; P= .99) and primary discharge diagnosis from index stay (P= 0.31) were not predictive of readmission; only the Rothman Index was (95% CI, -0.136 to -0.039; P<.001).The coefficient of the Rothman Index was -0.088, indicating that for each 1 point increase in Rothman Index, a patient’s odds of readmission within 30 days declined by 8.8% (95% CI, -0.136 to -0.039; P< .001). Conclusions: The Rothman Index can be utilized as a predictive tool to identify patients at high risk of unplanned 30-day hospital readmission, thereby allowing health systems to strategically allocate outside hospital resources.