Disparities in reportable quality metrics by insurance status in the primary spine neoplasm population

The Centers for Medicare and Medicaid Services (CMS) defines "adverse quality events" as the incidence of certain complications such as postsurgical hematoma or iatrogenic pneumothorax during an inpatient stay. Patient safety indicators (PSI) are a means to measure the incidence of these adverse events. When adverse events occur, reimbursement to the hospital decreases. The incidence of adverse quality events among patients hospitalized for primary spinal neoplasms is unknown. Similarly, it is unclear what the impact of insurance status is on adverse care quality among this patient population.

We aimed to determine the incidence of PSI among patients admitted with primary spinal neoplasms, and to determine the association between insurance status and the incidence of PSI in this population.

This is a retrospective cohort study.

We included all patients, 18 years and older, in the Nationwide Inpatient Sample (NIS) who were hospitalized for primary spine neoplasms from 1998 to 2011.

Incidence of PSI from 1998 to 2011 served as outcome variable.

The NIS was queried for all hospitalizations with a diagnosis of primary spinal neoplasm during the inpatient episode from 1998 to 2011. Incidence of PSI was determined using publicly available lists of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes. Logistic regression models were used to determine the effect of primary payer status on PSI incidence. All comparisons were made between privately insured patients and Medicaid or self-pay patients.

We identified 6,095 hospitalizations in which a primary spinal neoplasm was recorded during the inpatient episode. We excluded patients younger than 18 years and those with "other" or "missing" primary insurance status, leaving 5,880 patients for analysis. After adjusting for patient demographics and hospital characteristics, Medicaid or self-pay patients had significantly greater odds of experiencing one or more PSI (odds ratio [OR] 1.81 95% confidence interval [CI] 1.11-2.95) relative to privately insured patients.

Among patients hospitalized for primary spinal neoplasms, primary payer status predicts the incidence of PSI, an indicator of adverse health-care quality used to determine hospital reimbursement by the CMS. As reimbursement continues to be intertwined with reportable quality metrics, identifying vulnerable populations is critical to improving patient care.