Myelomeningocele: surgical trends and predictors of outcome in the United States, 1988-2010

Abstract

Object: Myelomeningocele repair is an uncommonly performed surgical procedure. The volume of operations has been decreasing in the past 2 decades, probably as the result of public health initiatives for folate supplementation. Because of the rarity of myelomeningocele, data on patient or hospital factors that may be associated with outcome are scarce. To determine these factors, the authors investigated the trends in myelomeningocele surgical repair in the United States over a 23-year period and examined patient and hospital characteristics that were associated with outcome.

Methods: The Nationwide Inpatient Sample database for 1988-2010 was queried for hospital admissions for myelomeningocele repair. This database reports patient, hospital, and admission characteristics and surgical trends. The authors used univariate and multivariate logistic regression to assess associations between patient and hospital characteristics and in-hospital deaths, nonroutine discharge, long hospital stay, and shunt placement.

Results: There were 4034 hospitalizations for surgical repair of myelomeningocele. The annual volume decreased since 1988 but plateaued in the last 4 years of the study. The percentages of myelomeningocele patients with low income (30.8%) and Medicaid insurance (48.2%) were disproportionately lower than those for the overall live-born population (p < 0.0001). More operations per 10,000 live births were performed for Hispanic patients (3.2) than for white (2.0) or black (1.5) patients (p < 0.0001). Overall, 56.6% of patients required shunt placement during the same hospital stay as for surgical repair; 95.0% of patients were routinely discharged; and the in-hospital mortality rate was 1.4%. Nonwhite race was associated with increased in-hospital risk for death (OR 2.8, 95% CI 1.2-6.3) independent of socioeconomic or insurance status.

Conclusions: Overall, the annual surgical volume of myelomeningocele repairs decreased after public health initiatives were introduced but has more recently plateaued. The most disproportionately represented populations are Hispanic, low-income, and Medicaid patients. Among nonwhite patients, increased risk for in-hospital death may represent a disparity in care or a difference in disease severity.

Keywords: HCUP = Healthcare Cost and Utilization Project; ICD-9-CM = International Classification of Diseases, Ninth Revision, Clinical Modification; NIS = Nationwide Inpatient Sample; congenital; cost; epidemiology; myelomeningocele; socioeconomics; spina bifida.