The Rothman Index as a predictor of postdischarge adverse events after elective spine surgery

Background context: The Rothman Index (RI) is a comprehensive rating of overall patient condition in the hospital setting. It is used at many medical centers and calculated based on vital signs, laboratory values, and nursing assessments in the electronic medical record. Previous research has demonstrated an association with adverse events, readmission, and mortality in other fields, but it has not been investigated in spine surgery.

Purpose: The present study aims to determine the potential utility of the RI as a predictor of adverse events after discharge following elective spine surgery.

Study design/setting: This retrospective cohort study was carried out at a large academic medical center.

Patient sample: A total of 2,687 patients who underwent elective spine surgery between 2013 and 2016 were included in the present study.

Outcome measures: The occurrence of adverse events and readmission after discharge from the hospital, within postoperative day 30, was determined in the present study.

Methods: Patient characteristics and 30-day perioperative outcomes were characterized, with events being classified as "major adverse events" or "minor adverse events" using standardized criteria. Rothman Index scores from the hospitalization were analyzed and compared for those who did or did not experience adverse events after discharge. The association of lowest and latest scores on adverse events was determined with multivariate regression, controlling for demographics, comorbidities, surgical procedure, and length of stay.

Results: Postdischarge adverse events were experienced by 7.1% of patients. The latest and lowest RI values were significantly inversely correlated with any adverse events, major adverse events, minor adverse events and readmissions after controlling for age, gender, body mass index, American Society of Anesthesiologists (ASA) class, surgical site, and hospital length of stay. Rates of readmission and any adverse event consistently had an inverse correlation with lowest and latest RI scores, with patients at increased risk with lowest score below 65 or latest score below 85.

Conclusions: The RI is a tool that can be used to predict postdischarge adverse events after elective spine surgery that adds value to commonly used indices such as patient demographics and ASA. It is found that this can help physicians identify high-risk patients before discharge and should be able to better inform clinical decisions.