Comparable on-therapy mortality and supportive care requirements in Black and White patients following initial induction for pediatric acute myeloid leukemia

Understanding Disparities in the Pediatric ICU: A Scoping Review

BACKGROUND AND OBJECTIVES

Health disparities are pervasive in pediatrics. We aimed to describe disparities among patients who are likely to be cared for in the PICU and delineate how sociodemographic data are collected and categorized.

METHODS

Using MEDLINE as a data source, we identified studies which included an objective to assess sociodemographic disparities among PICU patients in the United States. We created a review rubric, which included methods of sociodemographic data collection and analysis, outcome and exposure variables assessed, and study findings. Two authors reviewed every study. We used the National Institute on Minority Health and Health Disparities Research Framework to organize outcome and exposure variables.

RESULTS

The 136 studies included used variable methods of sociodemographic data collection and analysis. A total of 30 of 124 studies (24%) assessing racial disparities used self- or parent-identified race. More than half of the studies (52%) dichotomized race as white and "nonwhite" or "other" in some analyses. Socioeconomic status (SES) indicators also varied; only insurance status was used in a majority of studies (72%) evaluating SES. Consistent, although not uniform, disadvantages existed for racial minority populations and patients with indicators of lower SES. The authors of only 1 study evaluated an intervention intended to mitigate health disparities. Requiring a stated objective to evaluate disparities aimed to increase the methodologic rigor of included studies but excluded some available literature.

CONCLUSIONS

Variable, flawed methodologies diminish our understanding of disparities in the PICU. Meaningfully understanding and addressing health inequity requires refining how we collect, analyze, and interpret relevant data.

Pre- and Postnatal Exposures to Tobacco Smoking and Survival of Childhood Acute Lymphoblastic and Myeloid Leukemias in California, United States

BACKGROUND

Tobacco smoke adversely affects the prognosis of adult cancers including myeloid leukemia, but less is known in children.

METHODS

We evaluated whether pre- and postnatal exposures to tobacco smoke decrease 5-year survival of 1,235 childhood acute lymphoblastic leukemia (ALL) and 188 childhood acute myeloid leukemia (AML) cases derived from a population-based case-control study in California. Cases were diagnosed between 1995 and 2015 (median follow-up time of 13.2 years overall). We obtained data on tobacco smoking (before conception, during pregnancy, after birth), parental education and income, clinical features, and vital status through 2020. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for mortality associated with smoking, adjusting for sociodemographic characteristics and risk group (ALL only).

RESULTS

About 23% of mothers and 39% of fathers reported smoking and 130 children with ALL and 52 with AML died within 5 years. For AML, increased risks of death were observed among children whose fathers smoked before conception compared with nonsmoking fathers [HR = 1.41; 95% confidence interval (CI), 0.95-3.44 and 3.47; 95% CI, 1.37-8.81, respectively for <20 vs. ≥20 cigarettes per day; Ptrend = 0.01]. HR for child's passive smoking was 1.74, 95% CI, 0.81-3.73. Paternal preconception smoking may also reduce 5-year survival among ALL with favorable prognostic molecular subtypes (high hyperdiploidy and absence of IKZF1 gene deletion), although the associations did not reach statistical significance (Pheterogeneity = 0.07).

CONCLUSIONS

Paternal preconception smoking decreased 5-year survival of childhood AML.

IMPACT

Knowledge of exposure to tobacco smoking should be integrated in the treatment plan of childhood leukemias.

Racial and ethnic disparities in acuity of presentation among children with newly diagnosed acute leukemia

We evaluated disparities in disease burden, organ dysfunction, vital signs, and timing of therapy in children newly presenting with acute leukemia. Among 899 patients with acute leukemia diagnosed at two large children's hospitals, a priori lab-based definitions of high disease burden, infection risk, renal dysfunction, and coagulopathy were applied to electronic health record data. Black patients with acute myeloid leukemia had increased prevalence of elevated white blood cell count and uric acid; Black patients with acute lymphoblastic leukemia demonstrated increased prevalence of coagulopathy. Black patients' presentation more frequently included multiple lab abnormalities consistent with advanced physiologic dysfunction. No differences were found in days to therapy initiation.

Leveraging machine learning to identify acute myeloid leukemia patients and their chemotherapy regimens in an administrative database

BACKGROUND

Administrative datasets are useful for identifying rare disease cohorts such as pediatric acute myeloid leukemia (AML). Previously, cohorts were assembled using labor-intensive, manual reviews of patients' longitudinal chemotherapy data.

METHODS

We utilized a two-step machine learning (ML) method to (i) identify pediatric patients with newly diagnosed AML, and (ii) among the identified AML patients, their chemotherapy courses, in an administrative/billing database. Using 2558 patients previously manually reviewed, multiple ML algorithms were derived from 75% of the study sample, and the selected model was tested in the remaining hold-out sample. The selected model was also applied to assemble a new pediatric AML cohort and further assessed in an external validation, using a standalone cohort established by manual chart abstraction.

RESULTS

For patient identification, the selected Support Vector Machine model yielded a sensitivity of 0.97 and a positive predictive value (PPV) of 0.97 in the hold-out test sample. For course-specific chemotherapy regimen and start date identification, the selected Random Forest model yielded overall PPV greater than or equal to 0.88 and sensitivity greater than or equal to 0.86 across all courses in the test sample. When applied to new cohort assembly, ML identified 3016 AML patients with 10,588 treatment courses. In the external validation subset, PPV was greater than or equal to 0.75 and sensitivity was greater than or equal to 0.82 for patient identification, and PPV was greater than or equal to 0.93 and sensitivity was greater than or equal to 0.94 for regimen identifications.

CONCLUSION

A carefully designed ML model can accurately identify pediatric AML patients and their chemotherapy courses from administrative databases. This approach may be generalizable to other diseases and databases.

In-hospital Mortality and Racial Disparity in Children and Adolescents With Acute Myeloid Leukemia: A Population-based Study

Survival disparities in children and adolescents with acute myeloid leukemia (AML) are documented, however, the etiology of these disparities is understudied. Few studies have evaluated factors that predict in-hospital mortality in childhood AML and racial/ethnic disparities associated with in-hospital death. Our study aimed to investigate factors associated with the risk of in-hospital death among childhood AML hospitalizations. We conducted a retrospective study of childhood AML hospitalizations using the National Inpatient Sample (NIS) from 2003 to 2017. We estimated incidences of in-hospital death among AML hospitalizations. We performed survey logistic regression models to measure the association between patient and hospital characteristics and in-hospital mortality. We identified 71,050 hospitalizations of children with AML. Compared with non-Hispanic (NH) whites, NH-black children had a higher risk of in-hospital mortality (adjusted odds ratio: 1.41, 95% confidence interval: 1.06-1.87, P<0.02). Further, NH-black patients with hematopoietic stem cell transplant experienced the highest risk of mortality (adjusted odds ratio: 5.88, 95% confidence interval: 3.13-11.06, P<0.001) as compared with NH-black children who did not receive hematopoietic stem cell transplant. Our findings highlight that NH-black children with AML continue to experience a disproportionately higher likelihood of in-hospital mortality when compared with their NH-white counterparts. Further studies are needed to delineate the etiology of these disparities.

Demographic and socioeconomic disparities in pediatric cancer in the United States: Current knowledge, deepening understanding, and expanding intervention

While survival of pediatric cancer has improved greatly over the past 40 years, demographic and socioeconomic disparities have meant that some groups have not benefitted as much from these advances. We conducted a rapid review to summarize literature on demographic and socioeconomic disparities in outcomes of childhood cancer, starting in 2000. We find that unequal outcomes have been noted for many of these groups across hematologic malignancies, central nervous system tumors, and other solid tumors, although occasional studies have noted absence of disparities for particular at-risk groups and diseases, and gaps in understanding of disparities for some cancer subtypes and groups still exist. These include disparities in duration of overall survival, risk of death, more extensive disease at presentation, and differences/delays in treatment. Black race, Hispanic ethnicity, lack of private insurance, and adolescent/young adult age are most often associated with these poorer outcomes. We then delve into documented and theorized causes of these disparities, including impaired access to care and clinical trials, differences in cancer biology, treatment non-adherence, language barriers, and implicit racial bias. Here, it is clear that socioeconomic factors account for a large proportion of disparities seen, although not all, and that the causes of disparities are complex and interconnected and still need to be better understood. Finally, in an effort to shift emphasis to addressing disparities, we review interventions against disparities that have been studied in childhood cancer patients and other populations, including improving clinical trial representation, communication, health literacy, and family navigation. We suggest ways forward in disparity mitigation toward a goal of achieving equitable cancer outcomes for all children.

Association of race and ethnicity with clinical phenotype, genetics, and survival in pediatric acute myeloid leukemia

Cytogenetic lesions in pediatric AML differ by race-ethnicity including higher rates of specific poor prognosis lesions among Black children.

Racial-ethnic minorities experience worse outcomes in pediatric AML regardless of genetic disease features.

Black and Hispanic children with acute myeloid leukemia (AML) have worse outcomes compared with White children. AML is a heterogeneous disease with numerous genetic subtypes in which these disparities have not been specifically investigated. In this study, we used the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database to examine the association of race-ethnicity with leukemia cytogenetics, clinical features, and survival outcomes within major cytogenetic subgroups of pediatric AML. Compared with White non-Hispanic patients, t(8;21) AML was more prevalent among Black (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.28-3.74) and Hispanic patients (OR, 1.74; 95% CI, 1.05-2.83). The poor prognosis KMT2A rearrangement t(6;11)(q27;q23) was more prevalent among Black patients (OR, 6.12; 95% CI, 1.81-21.59). Among those with KMT2Ar AML, Black race was associated with inferior event-free survival (EFS) (hazard ratio [HR], 2.31; 95% CI, 1.41-3.79) and overall survival (OS) (HR, 2.54; 1.43-4.51). Hispanic patients with KMT2Ar AML also had inferior EFS (HR, 2.20; 95% CI, 1.27-3.80) and OS (HR, 2.07; 95% CI, 1.09-3.93). Similarly, among patients with t(8;21) or inv(16) AML (ie, core-binding factor [CBF] AML), Black patients had inferior outcomes (EFS HR, 1.93; 95% CI, 1.14-3.28 and OS HR, 3.24; 95% CI, 1.60-6.57). This disparity was not detected among patients receiving gemtuzumab ozogamicin (GO). In conclusion, racial-ethnic disparities in survival outcomes among young people with AML are prominent and vary across cytogenetic subclasses. Future studies should explore the socioeconomic and biologic determinants of these disparities.

Racial/Ethnic Minority Children With Cancer Experience Higher Mortality on Admission to the ICU in the United States

OBJECTIVE

We investigated whether differences in survival exist between children of various racial/ethnic groups with cancer admitted to the PICU.

DESIGN

A retrospective multicenter analysis was conducted using Virtual Pediatric Systems data from reporting centers. Demographic information, Pediatric Risk for Mortality III score, and outcome variables were analyzed using mixed-effects logistic regression modeling to assess for differences in mortality.

SETTING

One hundred thirty-five PICUs in the United States.

PATIENTS

Pediatric patients with cancer admitted to PICUs in the United States.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

This study details the analysis of 23,128 PICU admissions of 12,232 unique oncology patients representing 3% of all PICU admissions with 1,610 deaths (7.0% case fatality). African American (8.5%) and Hispanic children (8.1%) had significantly higher mortality (p < 0.05) compared with Caucasian children (6.3%). Regional analysis showed Hispanic patients to have higher mortality in the West in the United States, whereas African American patients in the South in the United States had higher mortality. A pulmonary disease diagnosis in Hispanics increased odds of mortality (odds ratio, 1.39; 95% CI, 1.13-1.70), whereas a diagnosis of shock/sepsis increased risk for mortality in African Americans (odds ratio, 1.56; 95% CI, 1.11-2.20) compared with Caucasians. There were no differences between races/ethnic groups in the rates of limitations of care. After controlling for Pediatric Risk of Mortality III, PICU length of stay, stem cell transplant status, readmissions, cancer type (solid, brain, hematologic), mechanical ventilation days, and sex, Hispanic (odds ratio, 1.24; 95% CI, 1.05-1.47) and African Americans (odds ratio, 1.37; 95% CI, 1.14-1.66) had significantly higher odds of mortality compared with Caucasians.

CONCLUSIONS

The results show that after controlling for severity and cancer type, a child's race, ethnicity, and region of presentation influence mortality in the PICU. This suggests that additional investigation is warranted along with a need to rethink our approach to the evaluation and treatment of critically ill African American and Hispanic children with cancer.

Cost-effectiveness of levofloxacin prophylaxis against bacterial infection in pediatric patients with acute myeloid leukemia

BACKGROUND

Infections are the leading cause of therapy-related mortality in pediatric patients with acute myeloid leukemia (AML). Although effectiveness of levofloxacin antibacterial prophylaxis in oncology patients is recognized, its cost-effectiveness is unknown. This study evaluated epidemiologic data regarding levofloxacin use and the cost-effectiveness of this strategy as the cost per bacteremia episode, intensive care unit (ICU) admission, and death avoided in children with AML.

PROCEDURE

A retrospective cohort study using the Pediatric Health Information System (PHIS) database compared demographic and clinical characteristics and receipt of levofloxacin prophylaxis in children with AML admitted for chemotherapy from January 1, 2014, through December 31, 2018. We then developed a decision analysis model in this population that compared costs associated with bacteremia, ICU admission, or death secondary to bacteremia to levofloxacin prophylaxis cost from a healthcare perspective. Time horizon is one chemotherapy cycle. Probabilistic and one-way sensitivity analyses evaluated model uncertainty.

RESULTS

Prophylaxis cost $8491 per bacteremia episode prevented compared with an average added hospital cost of $119 478. Prophylaxis cost $81 609 per ICU admission avoided, compared with an average added hospital cost of $94 181. Prophylaxis cost $220 457 per death avoided. In sensitivity analysis, at a willingness-to-pay threshold of $100 000 per bacteremia episode avoided, prophylaxis remained cost-effective in 94.6% of simulations. Prophylaxis use was more common in recent years in patients with relapsed disease and with chemotherapy regimens considered more intensive.

CONCLUSION

Prophylaxis is cost-effective in preventing bacterial infections in patients with AML. Findings support increased use in patients considered at high risk of bacterial infection secondary to myelosuppression.

Distance to treatment center is associated with survival in children and young adults with acute lymphoblastic leukemia

BACKGROUND

Socioeconomic and demographic categories such as income, race, insurance status, and treatment center type are associated with outcomes in acute leukemia. This study was aimed at determining whether the distance to treatment center affects overall survival for children and young adults with acute leukemia.

METHODS

The National Cancer Database was queried for patients 39 years old or younger who were diagnosed with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL). A backward elimination procedure was used to select final multivariate Cox models.

RESULTS

In total, 12,301 patients with AML and 22,683 patients with ALL were analyzed. The ALL model included distance to treatment center, Charlson-Deyo score, age, race, insurance status, and community income level. US census definitions of urban and rural were not statistically significant, and no interaction was significant for included variables. Compared with distances > 50 miles, all other distances were associated with improved survival (hazard ratio [HR] for ≤10 miles, 0.91; P = .04; HR for >10 to ≤20 miles, 0.86; P = .004; HR for >20 to ≤50 miles, 0.87; P = .005). The final model for AML included the same variables as the ALL model except for distance to treatment center, which was not statistically significant.

CONCLUSIONS

For children and young adults with ALL, distances > 50 miles are associated with inferior overall survival; however, no difference is seen for AML. Although it is unknown whether differences in survival for patients with ALL based on distance are driven by relapse or treatment-related mortality, increased attention to adherence, supportive care, and logistics for patients traveling long distances is warranted.

LAY SUMMARY

For children and young adults with acute lymphoblastic leukemia, living more than 50 miles from the treatment center is associated with worse outcomes.