Inpatient and 90-day post-discharge outcomes in elective Medicare spine fusion surgery.

BACKGROUND CONTEXT: Elective spine surgery is a commonly performed operative procedure, that requires knowledge of risk-adjusted results to improve outcomes and reduce costs.

PURPOSE: To develop risk-adjusted models to predict the adverse outcomes (AOs) of care during the inpatient and 90-day post-discharge period for spine fusion surgery.

STUDY DESIGN/SETTING: To identify the significant risk factors associated with AOs and to develop risk models that measure performance.

PATIENT SAMPLE: Hospitals that met minimum criteria of both 20 elective cervical and 20 elective non-cervical spine fusion operations in the 2012-2014 Medicare limited dataset.

OUTCOME MEASURES: The risk-adjusted AOs of inpatient deaths, prolonged length-of-stay for the index hospitalization, 90-day post-discharge deaths, and 90-day post-discharge readmissions were dependent variables in predictive risk models.

METHODS: Over 500 candidate risk factors were used for logistic regression models to predict the AOs. Models were then used to predicted risk-adjusted AO rates by hospitals.

RESULTS: There were 874 hospitals with a minimum of both 20 cervical and 20 non-cervical spine fusion patients. There were 167,395 total cases. A total of 7,981 (15.9%) of cervical fusion patients and 17,481 (14.9%) of non-cervical fusion patients had one or more AOs for an overall AO rate of 15.2%. A total of 54 hospitals (6.2%) had z-scores that were 2.0 better than predicted with a median risk adjusted AO rate of 9.2%, and 75 hospitals (8.6%) were 2.0 z-scores poorer than predicted with a median risk-adjusted AO rate of 23.2%.

CONCLUSIONS: Differences among hospitals defines opportunities for care improvement.