Using the Rothman index to predict early unplanned surgical intensive care unit readmissions

The Rothman index (RI) is a numerical score calculated hourly from 26 data points in the electronic medical record by a commercial software package. Although it is purported to serve as an indicator of change in a patient's condition, it has not been extensively evaluated in the literature. Our objective was to determine whether the RI can be used to predict early surgical intensive care unit (SICU) readmissions.

This is a single-institution, retrospective 12-month period review of all patients transferred from the SICU to the surgical floor. Patients readmitted to the SICU within 48 hours were compared with patients who did not require readmission during this time (control). Demographics and continuous RI scores were collected at admission, 24 hours before SICU transfer, and for the first 48 hours on the surgical floor or until readmission to the SICU.

A total of 1,152 SICU patients were transferred to the surgical floor; 27 patients were readmitted within 48 hours of transfer. Demographics were similar in both groups. The SICU length of stay was longer in the readmission group (mean [SD], 4.7 [8.1] vs. 16.5 [15.2]; p < 0.001). The RI immediately before SICU transfer was higher in the control group (70.4 [20.3] vs. 49.1 [20.9], p < 0.001) and was uniformly improved from the RI at the initial SICU admission. In comparison, readmitted patients had more variable RI trends from admission to SICU transfer (mean Δ, 6.51; range, -54.10 to 48.6), and 40.74% of readmitted patients actually had a decreased RI score on transfer. No patient with a RI score greater than 82.90 required readmission within 48 hours.

An increased RI score or a score greater than 82.90 correlates with appropriateness for SICU transfer to the surgical floor. A decreased RI score is strongly associated with SICU readmission within 48 hours and should be explored as a potential quality metric.

Epidemiologic/prognostic study, level III.