Dissecting Racial Outcome Disparities In Children With CHD Using Big Data
Lindsey Loveland Baptist M.D., Susan C. Nicolson M.D.
As soon as I read this article by Nasr et al.,(1) I asked Lindsey Loveland Baptist and Susan Nicolson to review it for the Pediatric Anesthesia Article of the Day. Lindsey and Susan are half of our pediatric cardiac anesthesia review team, the other half, Viviane Nasr and Jim Dinardo, are the authors of today’s article. Unfortunately, this article is yet another in a string of recent publications (mainly by Olubukola Nafiu at Nationwide Children’s Hospital)(2-5) revealing significantly worse outcomes following all kinds of surgery in non-white children. I applaud our colleagues for posing this question, despite the disappointing conclusion. Myron Yaster MD
Original Article
Nasr VG, Staffa SJ, DiNardo JA, Faraoni D. The Association Between Race and Adverse Postoperative Outcomes in Children With Congenital Heart Disease Undergoing Noncardiac Surgery. Anesth Analg. 2022 Feb 1;134(2):357-368. PMID: 33999011.
The survival rates of children with congenital heart disease (CHD) have increased significantly in recent years resulting in a growing population of children with CHD presenting for non-cardiac procedures and surgery. Nasr and colleagues set out to determine if there is an association between race and adverse postoperative outcomes in children with CHD undergoing non-cardiac surgery, stratified by severity of heart disease. They retrospectively analyzed big data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, from 2012-2018, including all children <18 years with CHD. The severity of CHD was classified as minor, major, or severe based on residual lesion burden and functional status. Minor was defined as a cardiac condition with or without medication and maintenance (e.g. ASD, small to moderate VSD with no symptoms) or repaired CHD with normal cardiovascular function and no chronic treatment. Major CHD was defined as repaired CHD with residual hemodynamic abnormality with or without medications (e.g. tetralogy of Fallot with wide open pulmonary insufficiency, hypoplastic left heart syndrome including S/P stage 1 repair). Severe CHD is defined as uncorrected cyanotic heart disease, patients with documented pulmonary hypertension, or patients listed for heart transplant. Primary comparisons were between white and black cohorts.
The primary outcome evaluated was 30-day mortality and secondary outcomes were: post-operative cardiac arrest, post-operative reintubation, infections (superficial or deep surgical site, respiratory, or urinary tract infections) renal failure (defined as acute renal failure or renal insufficiency), neurologic complications (seizures, coma, cerebral vascular events intraventricular hemorrhage), thromboembolic complications, reoperation, and any hospital readmission. The cohorts were propensity score matched (PSM). Absolute standardized mean differences (SMD) were used to evaluate the quality of the matching and balance of the groups.
In total, 55,859 children were included in this review, 76% were white and 19.4% were black. There were 28,601 children with minor, 23,839 with major and 3,419 with severe CHD. Before PSM there was an imbalance in the groups in prematurity, weight, preoperative mechanical ventilation, preoperative transfusion, and chronic lung disease. After PSM the balance was improved, although not equal. Following matching, in the overall cohort there were significantly more adverse postoperative outcomes among black patients as compared to white in multiple domains: 30-day mortality, the composite of all secondary outcomes, cardiac arrest, 30-day reoperation, and reintubation. In the propensity matched minor and major CHD groups significant differences remained between the black and white cohorts. No race-related outcome disparities were found between white and black children in the severe CHD subgroup.
The authors concluded that race is associated with postoperative mortality and complications in children with minor and major CHD who underwent non- cardiac surgery. Black children have a higher incidence of post-operative mortality and morbidity when compared to white children. The relative difference in outcome ranges from 10 – 113% higher among black children as compared to white. They didn’t find a difference in the severe cohort. This is consistent with previous findings that in patients with severe CHD residual lesions, and functional status are the leading predictors of outcomes. The authors speculated that children with severe CHD were more likely to be cared for at a specialized centers with expertise caring for this subset of patients.
The authors discuss the known higher risk of adverse events and mortality for black patients in other cohorts. Further analysis of the NSQIP database showed that the prevalence of preoperative risk factors associated with post-operative mortality was significantly higher for black than for white children and may account for the worse outcomes. However, many of the risk factors associated with death after surgery (mechanical ventilation, oxygen support, wound infection, and neonatal status) carried a higher risk when they occurred in black children. Because of the PSM the authors assert that the outcome differences are not explained by differences in patient condition and health status. That requires consideration of other possible determinants – size of the cohort, social determinants, hospital location and variables, family, and health care providers factors.
A simulation of regionalization of all congenital heart surgery in the U.S. demonstrated an overall mortality decrease from 3.5% to 3.1% (P <0.01) with a significant increase in mean patient travel distance from 38.5 to 69.6 miles.(6) This simulation sequentially moved patients to higher and higher volume centers by closest proximity to their home zip code, until the surgical volume was >311 cases per institution, And 37 hospitals remained in the model. However, modeling regionalization of just the high-risk operations did not result in a decrease in overall mortality. This suggests that regionalization of non-cardiac procedures for those with CHD may improve outcomes for patients with minor and major disease similar to how this model predicted an improvement in mortality by regionalizing cardiac procedures. In another recent study, Anderson et al.(7) found that children from the lowest income neighborhoods had a 1.18-time higher risk of mortality following cardiac surgery. The difference in mortality was only partially explained by differences in race, insurance, or hospital. This article is important because even in the fully adjusted model presented, black non-Hispanic children had 1.23 times the odds of mortality as white non-Hispanic children. This article also asks why these disparities exist despite adjusting for the factors that are believed to most strongly influence outcome. (7)
“Racial disparities may be related to issues at the provider level. Conscious careful analytical thinking (system II) relies on intuitive and unconscious System I thinking, which is where implicit bias resides. The data analyzed in this study is deidentified, so individual hospital and provider data is not available. Future studies to understand the mechanism leading to the racial difference, including institutional, clinical, and individual factors are needed.”(1)
The association between race and poorer outcomes has been well known to the black community for years and has been frustratingly difficulty to improve. Maternal mortality has been identified as starkly different for decades, and disparities have not changed significantly between 2007-08 and 2015-16. (https://www.cdc.gov/healthequity/features/maternal-mortality/index.html ) Nafiu et al. undertook an investigation of postoperative complications and death in healthy children (ASA 1 and 2) and found that African American children had 3.32 times the odds of dying withing 30 days of surgery as compared to their white peers. (4)
Nasr and colleagues are the 1st to put data to the problem in children with CHD, which is a shared language we can all use to become actively anti-racist. The article gives us another way to explore implicit bias, not only in individuals but at a systematic level and continue the dialogue and work.
References
1. Nasr VG, Staffa SJ, DiNardo JA, Faraoni D. The Association Between Race and Adverse Postoperative Outcomes in Children With Congenital Heart Disease Undergoing Noncardiac Surgery. Anesth Analg 2022;134:357-68.
2. Willer BL, Mpody C, Tobias JD, Nafiu OO. Racial Disparities in Failure to Rescue Following Unplanned Reoperation in Pediatric Surgery. Anesth Analg 2021;132:679-85.
3. Sivak E, Mpody C, Willer BL, Tobias J, Nafiu OO. Race and major pulmonary complications following inpatient pediatric otolaryngology surgery. Paediatr Anaesth 2021;31:444-51.
4. Nafiu OO, Mpody C, Kim SS, Uffman JC, Tobias JD. Race, Postoperative Complications, and Death in Apparently Healthy Children. Pediatrics 2020;146.
5. Baetzel AE, Holman A, Dobija N, Reynolds PI, Nafiu OO. Racial Disparities in Pediatric Anesthesia. Anesthesiol Clin 2020;38:327-39.
6. Welke KF, Pasquali SK, Lin P, Backer CL, Overman DM, Romano JC, Karamlou T. Regionalization of Congenital Heart Surgery in the United States. Semin Thorac Cardiovasc Surg 2020;32:128-37.
7. Anderson BR, Fieldston ES, Newburger JW, Bacha EA, Glied SA. Disparities in Outcomes and Resource Use After Hospitalization for Cardiac Surgery by Neighborhood Income. Pediatrics 2018;141.