Insurance status and reportable quality metrics in the cervical spine fusion population.

BACKGROUND CONTEXT

The incidence of adverse care quality events among patients undergoing cervical fusion surgery is unknown using the definition of care quality employed by the Centers for Medicare and Medicaid Services (CMS). The effect of insurance status on the incidence of these adverse quality events is also unknown.

PURPOSE

This study determined the incidence of hospital-acquired conditions (HAC) and patient safety indicators (PSI) in patients with cervical spine fusion and analyzed the association between primary payer status and these adverse events.

STUDY DESIGN

This is a retrospective cohort design.

PATIENT SAMPLE

All patients in the Nationwide Inpatient Sample (NIS) aged 18 and older who underwent cervical spine fusion from 1998 to 2011 were included.

OUTCOME MEASURES

Incidence of HAC and PSI from 1998 to 2011 served as outcome variables.

METHODS

We queried the NIS for all hospitalizations that included a cervical fusion during the inpatient episode from 1998 to 2011. All comparisons were made between privately insured patients and Medicaid or self-pay patients because Medicare enrollment is confounded with age. Incidence of nontraumatic HAC and PSI was determined using publicly available lists of International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes. We built logistic regression models to determine the effect of primary payer status on PSI and nontraumatic HAC.

RESULTS

We identified 419,424 hospitalizations with cervical fusion performed during an inpatient episode. The estimated national incidences of nontraumatic HAC and PSI were 0.35% and 1.6%, respectively. After adjusting for patient demographics and hospital characteristics, Medicaid or self-pay patients had significantly greater odds of experiencing one or more HAC (odds ratio [OR] 1.51 95% conflict of interest [CI] 1.23-1.84) or PSI (OR 1.52 95% CI 1.37-1.70) than the privately insured cohort.

CONCLUSIONS

Among patients undergoing inpatient cervical fusion, primary payer status predicts PSI and HAC (both indicators of adverse health-care quality used to determine hospital reimbursement by CMS). As the US health-care system transitions to a value-based payment model, the cause of these disparities must be studied to improve the quality of care delivered to vulnerable patient populations.