Amanda E. Janitz

Traffic-related air pollution and childhood acute leukemia in Oklahoma

BACKGROUND While many studies have evaluated the association between acute childhood leukemia and environmental factors, knowledge is limited. Ambient air pollution has been classified as a Group 1 carcinogen, but studies have not established whether traffic-related air pollution is associated with leukemia. The goal of our study was to determine if children with acute leukemia had higher odds of exposure to traffic-related air pollution at birth compared to controls. METHODS We conducted a case-control study using the Oklahoma Central Cancer Registry to identify cases of acute leukemia in children diagnosed before 20 years of age between 1997 and 2012 (n=307). Controls were selected from birth certificates and matched to cases on week of birth (n=1013). Using a novel satellite-based land-use regression model of nitrogen dioxide (NO2) and estimating road density based on the 2010 US Census, we evaluated the association between traffic-related air pollution and childhood leukemia using conditional logistic regression. RESULTS The odds of exposure to the fourth quartile of NO2 (11.19-19.89ppb) were similar in cases compared to controls after adjustment for maternal education (OR: 1.08, 95% CI: 0.75, 1.55). These estimates were stronger among children with acute myeloid leukemia (AML) than acute lymphoid leukemia, with a positive association observed among urban children with AML (4th quartile odds ratio: 5.25, 95% confidence interval: 1.09, 25.26). While we observed no significant association with road density, male cases had an elevated odds of exposure to roads at 500m from the birth residence compared to controls (OR: 1.39, 95% CI: 0.93, 2.10), which was slightly attenuated at 750m. CONCLUSIONS Although we observed no association overall between NO2 or road density, this was the first study to observe an elevated odds of exposure to NO2 among children with AML compared to controls suggesting further exploration of traffic-related air pollution and AML is warranted.

Benzene and childhood acute leukemia in Oklahoma

Background Although childhood cancer is a leading cause of childhood mortality in the US, evidence regarding the etiology is lacking. The goal of this study was to evaluate the association between benzene, a known carcinogen, and childhood acute leukemia. Methods We conducted a case‐control study including cases diagnosed with acute leukemia between 1997 and 2012 (n = 307) from the Oklahoma Central Cancer Registry and controls matched on week of birth from birth certificates (n = 1013). We used conditional logistic regression to evaluate the association between benzene, measured with the 2005 National‐Scale Air Toxics Assessment (NATA) at census tract of the birth residence, and childhood acute leukemia. Results We observed no differences in benzene exposure overall between cases and controls. However, when stratified by year of birth, cases born from 2005 to 2010 had a three–fold increased unadjusted odds of elevated exposure compared to controls born in this same time period (4th Quartile OR: 3.53, 95% CI: 1.35, 9.27). Furthermore, the estimates for children with acute myeloid leukemia (AML) were stronger than those with acute lymphoid leukemia, though not statistically significant. Conclusions While we did not observe an association between benzene and childhood leukemia overall, our results suggest that acute leukemia is associated with increased benzene exposure among more recent births, and children with AML may have increased benzene exposure at birth. Using the NATA estimates allowed us to assess a specific pollutant at the census tract level, providing an advantage over monitor or point source data. Our study, however, cannot rule out the possibility that benzene may be a marker of other traffic‐related exposures and temporal misclassification may explain the lack of an association among earlier births. HighlightsBenzene is a suspected, but uncertain, risk factor for childhood acute leukemia.Enhanced benzene estimates account for activity and multiple sources of exposure.Potential dose‐response relation revealed for benzene and acute myeloid leukemia.

Childhood cancer in children with congenital anomalies in Oklahoma, 1997 to 2009.

BACKGROUND Data-linkage studies have reported an association between congenital anomalies and childhood cancer. However, few studies have focused on the differences in the effect of congenital anomalies on cancer as a function of attained age. We aimed to examine associations between anomalies and childhood cancer as a function of attained age among children born in Oklahoma. METHODS Data were obtained from the Oklahoma State Department of Health from 1997 to 2009 (n = 591,235). We linked Vital Statistics records for singleton deliveries to the Oklahoma Birth Defects Registry and the Oklahoma Central Cancer Registry using name and birth date. To assess the relation between anomalies and childhood cancer, we used Cox regression analysis allowing for a nonproportional hazards for anomalies as a function of age. RESULTS There were 23,368 (4.0%) children with anomalies and 531 (0.1%) children with cancer. When considering 3-year age intervals, we detected an increased hazard of any childhood cancer in children with anomalies compared with those without anomalies before 1 year of age (hazard ratio, 14.1; 95% confidence interval, 8.3-23.7) and at 3 years of age (hazard ratio, 2.3; 95% confidence interval, 1.6-3.2). The increased hazard declined with increasing time since birth, with the effect diminished by 6 years of age. CONCLUSION Our results were consistent with previous studies indicating an increased rate of childhood cancer among children with anomalies at younger ages. Furthermore, our study added a methodological refinement of assessing the effect of anomalies as a function of attained age. Birth Defects Research (Part A) 106:633-642, 2016.

Racial and Ethnic Differences in Pregnancy Rates Following Intrauterine Insemination with a Focus on American Indians

BackgroundNo research exists on American Indian pregnancy rates following infertility treatment. Most racial/ethnic fertility research has focused on pregnancy following in vitro fertilization, with only rare studies looking at intrauterine insemination (IUI). The objective of our study was to compare fecundability following IUI by race/ethnicity, with a special focus on American Indians.MethodsThis was a retrospective analysis of subjects undergoing IUI July 2007–May 2012 at a university-based infertility clinic. The primary outcome was positive pregnancy test, with a secondary outcome of ongoing pregnancy/delivery (OP/D). We calculated risk ratios (RR) and 95% confidence intervals (CI) using cluster-weighted generalized estimating equations method to estimate modified Poisson regression models with robust standard errors to account for multiple IUI cycles in the same patient.ResultsA total of 663 females (median age 32) undergoing 2007 IUI cycles were included in the analysis. Pregnancy rates overall were 15% per IUI cycle. OP/D rates overall were 10% per IUI cycle. The American Indian patients had significantly lower pregnancy (RR 0.34, 95% CI 0.16–0.72) and OP/D rates (RR 0.33, 95% CI 0.12–0.87) compared to non-Hispanic whites when patient and cycle characteristics were controlled. Pregnancy and OP/D rates for blacks, Asians, and Hispanics did not differ from those of non-Hispanic whites.ConclusionsOur finding of lower IUI treatment success among American Indian patients is novel, as no published studies of assisted reproductive technology or other fertility treatments have examined this subgroup separately. Further investigation of patient and clinical factors that may mediate racial/ethnic disparities in fertility treatment outcomes is warranted.

Maternal and paternal occupational exposures and hepatoblastoma: results from the HOPE study through the Children’s Oncology Group

Little is known about the etiology of hepatoblastoma. We aimed to confirm the results of a previous study evaluating the association between parental occupational exposures and hepatoblastoma. In our case–control study, we identified cases (n=383) from the Children’s Oncology Group and controls from birth certificates (n=387), which were frequency matched to cases on year and region of birth, sex, and birth weight. Occupational exposure in the year before and during the index pregnancy was collected through maternal interview and analyzed using unconditional logistic regression. The odds of both paternal and maternal “Likely” exposure to paints was elevated among cases compared with controls (paternal odds ratio (OR): 1.71, 95% confidence interval (CI): 1.04, 2.81; maternal OR: 3.29, 95% CI: 0.32, 33.78) after adjustment for matching factors and the confounding factors of maternal race (maternal only) and household income. In addition, paternal exposure to other chemicals was also elevated when adjusting for matching factors only (OR: 1.53, 95% CI: 1.02, 2.30). The results of our study provide further evidence of an association between parental occupation and hepatoblastoma. These results warrant further investigation of the etiologically relevant timing of occupational exposure to fumes and chemicals related to hepatoblastoma.

Association between benzene and congenital anomalies in Oklahoma, 1997–2009

Objectives Although the most common cause of death in infants, little is known about the aetiology of congenital anomalies. Recent studies have increasingly focused on environmental exposures, including benzene. While benzene is known to affect the central nervous system, the effects on the developing fetus are unclear. Methods We conducted a retrospective cohort study to evaluate the association between ambient benzene exposure and the prevalence of congenital anomalies among 628 121 singleton births in Oklahoma from 1997 to 2009. We obtained benzene from the Environmental Protection Agency’s 2005 National-Scale Air Toxics Assessment for the census tract of the birth residence. We used modified Poisson regression with robust SEs to calculate prevalence proportion ratios (PPRs) and 95% CIs between quartiles of benzene exposure and critical congenital heart defects (CCHDs), neural tube defects (NTDs) and oral clefts adjusted for maternal education and tobacco use. Results Median benzene exposure concentration in Oklahoma was 0.57 µg/m3. We observed no association between benzene exposure and oral clefts, CCHDs or NTDs. When specific anomalies were examined, we observed an increased prevalence of cleft lip among those exposed to the second quartile of benzene compared with the first (PPR 1.50, 95% CI 1.05 to 2.13), though no association with higher levels of exposure. Conclusions Our findings do not provide support for an increased prevalence of anomalies in areas more highly exposed to benzene. Future studies would benefit from pooling data from multiple states to increase statistical power and precision in studies of air pollutants and specific anomalies.

Racial/Ethnic Differences in the Utilization of Infertility Services: A Focus on American Indian/Alaska Natives

Objectives Previous studies have identified racial/ethnic disparities in infertility care, but patterns among American Indian/Alaska Natives (AI/AN) have not been reported. Our objective was to evaluate infertility services use in the US by race/ethnicity using data from the National Survey of Family Growth (NSFG). Methods We analyzed female respondent data from the pooled NSFG cycles 2002, 2006–2010 and 2011–2013. Respondents reported use of infertility services and types of services. We calculated weighted crude and adjusted prevalence proportion ratios (PPR) and 95% confidence intervals (95% CI) using modified Poisson regression with robust error variances accounting for the complex survey design to compare infertility services use across race/ethnicities. Results Overall, 8.7% of women reported using medical services to get pregnant. The prevalence of using any medical service to help get pregnant was lower for American Indian/Alaska Native (AI/AN) (PPR: 0.60, 95% CI 0.43–0.83) and black (PPR: 0.53, 95% CI 0.44–0.63) compared to white women and in Hispanic compared to non-Hispanic women (PPR: 0.57, 95% CI 0.48–0.67). The prevalence of accessing treatment, testing, and advice also differed by race and ethnicity. Conclusions for Practice We observed disparities in accessing services to get pregnant among AI/AN and black women and reduced use of advice among Asian/Pacific Islanders compared to whites. We also observed reduced service utilization for Hispanic compared to non-Hispanic women. Differential utilization of specific services suggests barriers to infertility care may contribute to reproductive health disparities among underserved populations.

Assessing Statewide Need for Older Adult Health Promotion Services: The Oklahoma Experience

ABSTRACT The growing senior population and persistent poor health status of seniors in Oklahoma compels a fresh look at what health promotion services would be well received. Surveys were distributed to a list of registered voters aged 65 and older in Oklahoma with a total of 1,248 surveys returned (19.8%). Survey items asked about interests in services, classes, and activities, plus current barriers to accessing and/or engaging in such programs. To account for survey weighting, Rao-Scott Chi-Square Tests were performed to determine differences by demographic characteristics. We identified services, classes, and activities that were (and were not) of interest to seniors in Oklahoma with legal assistance (52.1%), exercise classes (46.6%), internet classes (40.7%), and indoor exercise activities (45.5%) receiving the highest level of interest. Barriers to interest in participating in programs included not wanting to go and not knowing availability of such services. The results of this survey provide useful data on health promotion gaps for seniors, interests and barriers to engaging in such activities, and guidance for statewide program development. Future program development needs to be focused on areas of interest for older adults, including legal assistance, exercise classes, and internet classes.

Results from the 2013 Senior's Health Services Survey: Rural and Urban Differences

Purpose: The purpose of this study was to compare and contrast health education needs of rural Oklahomans aged 65 and older compared to urban and sub-urban populations. Methods: Surveys were distributed to a list of registered voters age 65 and older in Oklahoma with a total of 1,248 surveys returned. Survey items asked about interests in services, classes and activities, plus current barriers to accessing and/or engaging in such programs. Findings: Survey respondents living in large rural towns (23.7%) and the urban core (21.5%) were significantly more likely than those in small rural towns (14.0%) or sub-urban areas (15.5%) to have attended a free health information event in the past year (P=0.0393). Older Oklahomans in small towns and isolated rural areas reported more frequently than those in the urban core that they would participate in congregate meals at a center (small town/isolated rural: 14.4%, urban core: 7.2%) (P=0.05). Lack of adequate facilities was more frequently reported by those residing in small town and isolated rural areas compared to urban core areas (16.4% vs. 7.8%, P=0.01). Finally, older Oklahomans in the large rural towns (0.6%) and small town and isolated rural locations (2.13%) less frequently reported use of senior information lines (Senior Infoline) than those in the urban core (6.0%) and in sub-urban areas (7.1%) (P=0.0009). Conclusions: Results of this survey provide useful data on senior interests and current barriers to community programs/activities have some unique trends among both urban and rural populations.

Evaluation of geoimputation strategies in a large case study

BackgroundHealth data usually has missing or incomplete location information, which impacts the quality of research. Geoimputation methods are used by health professionals to increase the spatial resolution of address information for more accurate analyses. The objective of this study was to evaluate geo-imputation methods with respect to the demographic and spatial characteristics of the data.MethodsWe evaluated four geoimputation methods for increasing spatial resolution of records with known locational information at a coarse level. In order to test and rigorously evaluate two stochastic and two deterministic strategies, we used the Texas Sex Offender registry database with over 50,000 records with known demographic and coordinate information. We reduced the spatial resolution of each record to a census block group and attempted to recover coordinate information using the four strategies. We rigorously evaluated the results in terms of the error distance between the original coordinates and recovered coordinates by studying the results by demographic sub groups and the characteristics of the underlying geography.ResultsWe observed that in estimating the actual location of a case, the weighted mean method is the most superior for each demographic group followed by the maximum imputation centroid, the random point in matching sub-geographies and the random point in all sub-geographies methods. Higher accuracies were observed for minority populations because minorities tend to cluster in certain neighborhoods, which makes it easier to impute their location. Results are greatly affected by the population density of the underlying geographies. We observed high accuracies in high population density areas, which often exist within smaller census blocks, which makes the search space smaller. Similarly, mapping geoimputation accuracies in a spatially explicit manner reveals that metropolitan areas yield higher accuracy results.ConclusionsBased on gains in standard error, reduction in mean error and validation results, we conclude that characteristics of the estimated records such as the demographic profile and population density information provide a measure of certainty of geographic imputation.