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.