Questionnaire format of modified frailty index as a predictor for 30-day readmission and length of stay in elderly patients undergoing multi-level lumbar interbody fusion

Background: Frailty is a spectrum describing a demographic more likely to experience adverse events such as falls, disability, and hospital admission which can be quantified by the modified frailty index (mFI). Several studies have associated increased mFI score with higher rates of hospital readmission and length of stay (LOS). This study tests the predictive value of a frailty questionnaire based on the mFI on LOS and 30-day readmission rates. Methods: This retrospective chart review included all patients aged 60 or older who underwent multi-level LIF by 13 surgeons at a single institution. Patients were classified as frail (mFI > 1) or non-frail (mFI <= 1). Statistical analysis was performed on Microsoft Excel and included t-testing, linear correlations, and analysis of variance. Results: A total of 213 patients were included in the study with an average frailty score of 2.26. Frail patients had significantly increased LOS (P < 0.001) with no significant difference between vertebral levels (P = 0.27). Linear correlations between frailty score and LOS or readmission rate were positive in all cases with variable strength dependent on number of levels fused. Conclusions The frailty questionnaire is an effective method of predicting LOS and risk of 30-day post-operative readmission in elderly patients undergoing multi-level LIF. The questionnaire format will allow for increased ease of obtaining frailty scores, so that improved pre-operative decision-making can be made among clinicians and patients alike. Future studies may be performed to identify the best method of interpreting frailty scores and may be expanded to a multi-institutional level.