Kelly D. Getz

Laterality defects in the national birth defects prevention study (1998-2007): birth prevalence and descriptive epidemiology.

Little is known epidemiologically about laterality defects. Using data from the National Birth Defects Prevention Study (NBDPS), a large multi‐site case‐control study of birth defects, we analyzed prevalence and selected characteristics in children born with laterality defects born from 1998 to 2007. We identified 517 nonsyndromic cases (378 heterotaxy, 73.1%; 139 situs inversus totalis [SIT], 26.9%) resulting in an estimated birth prevalence of 1.1 per 10,000 live births (95% confidence interval 1.0–1.2). Prevalence did not differ significantly across sites, over time, or by inclusion of pregnancy termination. Laterality defects were more common among preterm cases compared to term cases, and in children born to mothers who were non‐white or younger than 20 years compared to white mothers or those age 25–29 years. The distribution of associated cardiac and extra‐cardiac defects, excluding the expected heterotaxy anomalies, varied by type of laterality defect. Cases with heterotaxy were significantly more likely than those with SIT to have double outlet right ventricle, atrioventricular canal defects, pulmonary stenosis, non‐tetralogy of Fallot pulmonary atresia with ventricular septal defect, totally and partially anomalous pulmonary venous return; also more likely to have orofacial clefts, esophageal atresia, bowel atresias, and omphalocele, though not reaching statistical significance. Relatively more common among cases with SIT were Dandy‐Walker malformation, anotia/microtia, and limb deficiency. The similarity in the demographic characteristics of heterotaxy and SIT supports the hypothesis that they are part of a continuum of abnormal left‐right axis patterning. These findings on laterality defects may help guide clinical care, future research, and prevention strategies.

Delayed diagnosis of critical congenital heart defects: trends and associated factors

OBJECTIVE: We aimed to examine trends in timing of diagnosis of critical congenital heart defects (CCHDs) and factors associated with delayed diagnosis (diagnosis after discharge home following delivery). METHODS: We examined a population-based retrospective cohort of CCHD cases among live births identified through the Massachusetts Birth Defects Monitoring Program. Congenital heart defects were considered critical if the infant received corrective surgery, interventional catheterization, palliative care, or died as a result of the defect within 12 months of birth. Timing of initial diagnosis was classified as prenatal, postnatal before discharge home, or delayed. Demographic, perinatal, and mortality information was obtained from the Registry of Vital Records and Statistics. Prevalence ratios (PRs) were used to examine associations with delayed diagnosis. RESULTS: Among 460 467 live births to Massachusetts residents between 2004 and 2009, we identified 916 CCHD cases, of which 126 (13.8%) had delayed diagnosis. Rates of prenatal CCHD diagnosis increased from 44.9% in 2004 to 63.8% in 2009, whereas rates of delayed diagnosis decreased from 17.1% to 10.6% over the same time period. Among cases with delayed diagnosis, the most common defects were coarctation, pulmonary valve stenosis, and tetralogy of Fallot. Delayed diagnosis was associated with delivery outside a tertiary hospital (adjusted PR: 3.6 [95% confidence interval: 2.5–5.2]) and isolated CCHD (adjusted PR: 1.7 [95% confidence interval: 1.1–2.7]). CONCLUSIONS: Despite increasing prenatal diagnosis of CCHDs, delayed diagnosis still occurs in over 10% of cases. Understanding factors associated with delayed diagnosis could help to improve prenatal and postnatal screening efforts, including pulse oximetry testing.

Maternal Pre-pregnancy Body Mass Index and Autism Spectrum Disorder among Offspring: A Population-Based Case–Control Study

BACKGROUND Previous studies have attributed high maternal weight gain during pregnancy and pre-pregnancy obesity to a higher risk for autism spectrum disorder (ASD). Maternal underweight was not previously explored with respect to ASD risk. METHODS We evaluated the association between maternal pre-pregnancy body mass index (BMI) and ASD occurrence among singletons born into the General Practice Research Database from 1993 to 2008. Case subjects were children with a diagnosis of ASD from birth to 2010. Up to four control subjects were matched to each case subject on birth year, sex, and general practice. Restricted cubic splines were used to assess the non-linearity of the association between maternal BMI and ASD. All study subjects were classified as underweight, normal weight, overweight, or obese based on maternal pre-pregnancy BMI using the WHO Classification Standard. Conditional logistic regression was used to calculate unadjusted and multivariable adjusted odds ratios for the association between categorical BMI (reference=normal weight) and the occurrence of ASD. RESULTS The association between maternal BMI and ASD occurrence was non-linear and J-shaped. The adjusted ORs for maternal underweight and obesity were 1.43 (95% CI 1.01, 2.04) and 1.54 (95% CI 1.26, 1.89) respectively. CONCLUSIONS Results suggest that extremes in maternal BMI may be associated with modest increases in the risk for ASD among offspring.

Short interpregnancy interval and gastroschisis risk in the national birth defects prevention study

BACKGROUND The micronutrient depletion hypothesis proposes that consecutive pregnancies spaced too closely may leave insufficient time for maternal micronutrient replenishment. Short interpregnancy intervals (IPI) have been associated with an increased risk for several adverse pregnancy outcomes, but an association with gastroschisis risk has not been previously explored. METHODS Within a population-based, case-control study, we evaluated the association between IPI length and gastroschisis risk using multivariable logistic regression models to estimate gastroschisis odds ratios for IPI <12 months and 12 to 17 months relative to those 18 to 23 months. We further evaluated the association between IPI and gastroschisis risk stratified by maternal age, periconceptional multivitamin use, preceding pregnancy outcome, study center region, and season of conception to explore whether observed associations were compatible with the hypothesis of maternal micronutrient depletion. RESULTS For women with IPI <12 months, the adjusted odds ratio (aOR) was 1.7 (95% confidence interval [CI]: 1.1-2.5). The magnitude of the observed effect did not differ among strata of maternal age or periconceptional multivitamin use. However, the association was more pronounced after a miscarriage or termination (aOR: 2.5; 95% CI: 1.1-5.6) and among women who resided in northern study areas (aOR: 2.8; 95% CI: 1.3-5.9). The higher risk observed with short IPI among women in northern study areas was attenuated for spring/summer conceptions. CONCLUSION Short IPI was associated with an increased risk for gastroschisis, particularly among women whose preceding pregnancy resulted in a miscarriage or termination and among those who resided in northern study areas with winter/fall conception.

Prenatal and Early Childhood Exposure to Tetrachloroethylene and Adult Vision

Background: Tetrachloroethylene (PCE; or perchloroethylene) has been implicated in visual impairments among adults with occupational and environmental exposures as well as children born to women with occupational exposure during pregnancy. Objectives: Using a population-based retrospective cohort study, we examined the association between prenatal and early childhood exposure to PCE-contaminated drinking water on Cape Cod, Massachusetts, and deficits in adult color vision and contrast sensitivity. Methods: We estimated the amount of PCE that was delivered to the family residence from participants’ gestation through 5 years of age. We administered to this now adult study population vision tests to assess acuity, contrast sensitivity, and color discrimination. Results: Participants exposed to higher PCE levels exhibited lower contrast sensitivity at intermediate and high spatial frequencies compared with unexposed participants, although the differences were generally not statistically significant. Exposed participants also exhibited poorer color discrimination than unexposed participants. The difference in mean color confusion indices (CCI) was statistically significant for the Farnsworth test but not Lanthony’s D-15d test [Farnsworth CCI mean difference = 0.05, 95% confidence interval (CI): 0.003, 0.10; Lanthony CCI mean difference = 0.07, 95% CI: –0.02, 0.15]. Conclusions: Prenatal and early childhood exposure to PCE-contaminated drinking water may be associated with long-term subclinical visual dysfunction in adulthood, particularly with respect to color discrimination. Further investigation of this association in similarly exposed populations is necessary.

Comparison of in-patient costs for children treated on the AAML0531 clinical trial: A report from the Children's Oncology Group.

A better understanding of drivers of treatment costs may help identify effective cost containment strategies and prioritize resources. We aimed to develop a method for estimating inpatient costs for pediatric patients with acute myeloid leukemia (AML) enrolled on NCI‐funded Phase III trials, compare costs between AAML0531 treatment arms (standard chemotherapy ± gemtuzumab ozogamicin (GMTZ)), and evaluate primary drivers of costs for newly diagnosed pediatric AML.

Merging Children's Oncology Group Data with an External Administrative Database Using Indirect Patient Identifiers: A Report from the Children's Oncology Group.

Purpose Clinical trials data from National Cancer Institute (NCI)-funded cooperative oncology group trials could be enhanced by merging with external data sources. Merging without direct patient identifiers would provide additional patient privacy protections. We sought to develop and validate a matching algorithm that uses only indirect patient identifiers. Methods We merged the data from two Phase III Children’s Oncology Group (COG) trials for de novo acute myeloid leukemia (AML) with the Pediatric Health Information Systems (PHIS). We developed a stepwise matching algorithm that used indirect identifiers including treatment site, gender, birth year, birth month, enrollment year and enrollment month. Results from the stepwise algorithm were compared against the direct merge method that used date of birth, treatment site, and gender. The indirect merge algorithm was developed on AAML0531 and validated on AAML1031. Results Of 415 patients enrolled on the AAML0531 trial at PHIS centers, we successfully matched 378 (91.1%) patients using the indirect stepwise algorithm. Comparison to the direct merge result suggested that 362 (95.7%) matches identified by the indirect merge algorithm were concordant with the direct merge result. When validating the indirect stepwise algorithm using the AAML1031 trial, we successfully matched 157 out of 165 patients (95.2%) and 150 (95.5%) of the indirectly merged matches were concordant with the directly merged matches. Conclusions These data demonstrate that patients enrolled on COG clinical trials can be successfully merged with PHIS administrative data using a stepwise algorithm based on indirect patient identifiers. The merged data sets can be used as a platform for comparative effectiveness and cost effectiveness studies.

A comparison of resource utilization following chemotherapy for acute myeloid leukemia in children discharged versus children that remain hospitalized during neutropenia.

Comparisons of early discharge and outpatient postchemotherapy supportive care in pediatric acute myeloid leukemia (AML) patients are limited. We used data from the Pediatric Health Information System on a cohort of children treated for newly diagnosed AML to compare course‐specific mortality and resource utilization in patients who were discharged after chemotherapy to outpatient management during neutropenia relative to patients who remained hospitalized. Patients were categorized at each course as early or standard discharge. Discharges within 3 days after chemotherapy completion were considered “early”. Resource utilization was determined based on daily billing data and reported as days of use per 1000 hospital days. Inpatient mortality, occurrence of intensive care unit (ICU)‐level care, and duration of hospitalization were compared using logistic, log‐binomial and linear regression methods, respectively. Poisson regression with inpatient days as offset was used to compare resource use by discharge status. The study population included 996 patients contributing 2358 treatment courses. Fewer patients were discharged early following Induction I (7%) than subsequent courses (22–24%). Across courses, patients discharged early experienced high readmission rates (69–84%), yet 9–12 fewer inpatient days (all P < 0.001). Inpatient mortality was low across courses and did not differ significantly by discharge status. The overall risk for ICU‐level care was 116% higher for early compared to standard discharge patients (adjusted risk ratio: 2.16, 95% confidence interval: 1.50, 3.11). Rates of antibiotic, vasopressor, and supplemental oxygen use were consistently elevated for early discharge patients. Despite similar inpatient mortality to standard discharge patients, early discharge patients may be at greater risk for life‐threatening chemotherapy‐related complications, including infections.

The Role of Acuity of Illness at Presentation in Early Mortality in Black Children with Acute Myeloid Leukemia.

Black patients with acute myeloid leukemia (AML) experience higher mortality than White patients. We compared induction mortality, acuity of illness prior to chemotherapy, and insurance type between Black and White patients to assess whether acuity of presentation mediates the disparity. Within a retrospective cohort of 1,122 children with AML treated with two courses of standard induction chemotherapy between 2004 and 2014 in the Pediatric Health Information System (PHIS) database, the association between race (Black versus White) and inpatient mortality during induction was examined. Intensive Care Unit (ICU)‐level resource utilization during the first 72 hours following admission for initial AML chemotherapy was evaluated as a potential mediator. The total effect of race on mortality during Induction I revealed a strong association (unadjusted HR 2.75, CI: 1.18, 6.41). Black patients had a significantly higher unadjusted risk of requiring ICU‐level resources within the first 72 hours after initial presentation (17% versus 11%; RR 1.52, CI: 1.04, 2.24). Mediation analyses revealed the indirect effect of race through acuity accounted for 61% of the relative excess mortality during Induction I. Publicly insured patients experienced greater induction mortality than privately insured patients regardless of race. Black patients with AML have significantly greater risk of induction mortality and are at increased risk for requiring ICU‐level resources soon after presentation. Higher acuity amongst Black patients accounts for a substantial portion of the relative excess mortality during Induction I. Targeting factors affecting acuity of illness at presentation may lessen racial disparities in AML induction mortality.

Resource Utilization and Toxicities After Carboplatin/Etoposide/Melphalan and Busulfan/Melphalan for Autologous Stem Cell Rescue in High-Risk Neuroblastoma Using a National Administrative Database

High‐dose chemotherapy with autologous stem cell rescue (ASCR) is a key component of high‐risk neuroblastoma therapy. Resources required to support patients treated with ASCR conditioning regimens [carboplatin/etoposide/melphalan (CEM) and busulfan/melphalan (BuMel)] have not been directly compared.