Differences in treatments and outcomes for idiopathic scoliosis patients treated in the United States from 1998 to 2007: impact of socioeconomic variables and ethnicity

Abstract

Background context: Scoliosis is a significant cause of disability and health-care resource utilization in the United States.

Purpose: Our aim was to evaluate potential disparities in the selection of treatments and outcomes for idiopathic scoliosis patients on a national level. To date, only one study has examined inpatient complications, discharge disposition, and mortality with respect to scoliosis treatment on a national scale.

Study design/setting: Retrospective review of cases having a primary diagnosis of idiopathic scoliosis using the nationwide inpatient sample (NIS) administrative data from 1998 to 2007.

Patient sample: The NIS data were queried to identify patients with a primary diagnosis of idiopathic scoliosis (International Classification of Diseases, Ninth Revision [ICD-9] diagnosis code: 737.30) admitted routinely. Surgically treated patients were identified as those patients who underwent a spinal fusion (ICD-9-Clinical Modification code: 81.08) as a principal procedure.

Outcome measures: Rates of surgical versus nonsurgical treatments were measured as were inhospital complications and mortality rates.

Methods: No external funding was received for this work. Univariate and multivariate analyses evaluated race, sex, socioeconomic factors, and hospital characteristics as predictors of surgical versus nonsurgical treatments, as well as inhospital complications and mortality rates.

Results: The study analyzed 9,077 surgically and 1,098 nonsurgically treated patients with idiopathic scoliosis. Univariate analysis showed both patient- and hospital-level variables as strongly associated with surgical versus nonsurgical treatments and outcomes. Multivariate analysis revealed that Caucasians and private insurance patients were more likely to undergo surgical treatment (p<.05) even when controlling for comorbidities. Additionally, Caucasians had a reduced risk of nonroutine discharge compared with non-Caucasians (p=.03). Large hospitals had higher surgery rates (p=.08) than small- or medium-sized facilities and a lower risk of mortality (p=.04). Caucasians (65.1%) were more commonly admitted to large teaching hospitals than African American (59.8%) or Hispanic (41.8%) patients.

Conclusions: Differences were found in the selection of surgical versus nonsurgical treatments, as well as inhospital morbidity for hospitalized idiopathic scoliosis patients based on ethnic and socioeconomic variables. This may in part be because of differences in access to the resources of large teaching hospitals for different ethnic and socioeconomic groups or variability in severity of scoliosis among these groups that was not captured in this database.