Courtney Walker

Ms. Courtney Walker


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
10 February 2023 in Cancer Epidemiology, Biomarkers & Prevention
Verified
Journal Article
Open access
PDF file
SKShama D Karanth
Shama D Karanth
TATomi Akinyemiju
Tomi Akinyemiju
CWCourtney Walker
Courtney Walker
DYDanting Yang
Danting Yang
CMCesar Migliorati
Cesar Migliorati
Dejana BraithwaiteDejana Braithwaite
Dejana Braithwaite
Background: Head and neck cancer (HNC) mortality differs by race, ethnicity, and socioeconomic status (SES). However, it is unclear whether the relationship between race/ethnicity and HNC-specific mortality varies according to the residence-level SES. Methods: Data from the Surveillance Epidemiology and End Results database included participants with primary HNC between 2006 and 2017 (followed through 2018) to assess the joint association of race/ethnicity and census-tract level SES Yost-index groups (quintiles) with all-cause and HNC-specific mortalities. Relative survival rates at 1, 5, and 10 years were calculated. Multivariable Cox proportional hazard regression models estimated hazard-ratios and 95% confidence intervals for all-cause mortality, and Fine-Gray subdistribution hazard models for HNC-specific mortality. Cumulative incidence curves for HNC-specific deaths were estimated. Results: 76,095 patients were included in the analysis: 63.2% were <65 years, 73.4% male, and 11.3% non-Hispanic (NH) Black. Most patients (58.3%) were diagnosed at regional or distant stages and 20.6% died of HNC. The five-year relative survival rate increased with SES group, with 51.6% in the lowest SES group, and 74.1% in the highest SES group. NH-Black patients had higher risk of all-cause and HNC-specific mortality than NH-White patients, regardless of the SES group. NH-Asian/Pacific Islander and Hispanic patients had higher risk of HNC-specific mortality in some SES groups. Conclusions: NH-Black patients of all SES strata had significantly worse outcomes. Other factors, such as healthcare quality, may be associated with persistent disparities. Impact: The study highlights the persistence of significant racial disparities in HNC survival across socioeconomic categories. There is need to consider additional factors underlying these disparities.

20 September 2022 in PLOS ONE
Verified
Journal Article
Open access
PDF file
CWCourtney Walker
Courtney Walker
WCWarren Christian
Warren Christian
AKAnna Kucharska-Newton
Anna Kucharska-Newton
SBSteven R. Browning
Steven R. Browning
This cross-sectional study assessed geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP) in primiparous mothers and exposure to industrial emissions using geocoded residential information from Kentucky live (N = 210,804) and still (N = 1,247) birth records (2008–2017) and census block group estimates of aerosol concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), selenium (Se), and zinc (Zi) from the Risk Screening Environmental Indicators (RSEI) model. A latent class analysis allowed for the identification of four district exposure classes—As, Cd, and Pb (12.6%); Se and Zi (21.4%); Pb and Cr (8%); and low or no exposures (57.9%). Women classified as having a high probability of exposure to both Pb and Cr had a statistically significantly greater prevalence of eHDP after adjusting for demographic factors (aPR = 1.22, 95% CI: 1.04, 1.44) relative to those with low or no exposure. Our findings contribute to the emerging literature on the association of metal exposures with pregnancy outcomes.

11 August 2022 in PLOS ONE
Verified
Journal Article
Open access
PDF file
DCDaniel B. Cooper
Daniel B. Cooper
CWCourtney Walker
Courtney Walker
WCWarren Christian
Warren Christian
Extraction of coal through mountaintop removal mining (MTR) alters many dimensions of the landscape. Explosive blasts, exposed rock, and coal washing have the potential to pollute air and water. Previous research suggests that infants born to mothers living in areas with MTR have a higher prevalence of birth defects. In this cross-sectional study, we further examine the relationship between MTR activity and several types of birth defects. Maternal exposure to MTR was assessed using remote sensing data from Skytruth, which captures MTR activity in the Central Appalachian region of the United States. Active MTR area was quantified within a five-kilometer buffer surrounding geocoded maternal address captured on birth records for live births to Appalachian Kentucky mothers between 1997 and 2003 (N = 95,581). We assigned high, medium, and low exposure based on the tertile of total MTR area within 5-km, and births with no MTR within this buffer were assigned zero exposure. The presence or absence of a birth defect grouped into six major organ systems was identified using birth records alone. Finally, we applied conditional multiple imputation for variables with missing values before conducting separate multivariable log-binomial regression models for each birth defect group. Prevalence ratio (PR) estimates were adjusted for individual level covariates from birth records. The prevalence of gastro-intestinal defects was significantly higher in birth records with high and low active MTR exposure compared to records with no exposure. (High exposure: PR = 1.99, 95% CI = 1.14–3.47; low exposure PR = 1.88, 95% CI = 1.06–3.31). This study supports some of the existing findings of previous ecological studies. Research addressing the relationship between gastro-intestinal birth defects and MTR coal mining is warranted but should carefully consider temporal dimensions of exposure.

6 May 2022 in Geospatial Health
Verified
Journal Article
Open access
PDF file
CWCourtney Walker
Courtney Walker
SSteve Browning
Steve Browning
JLJeffrey E. Levy
Jeffrey E. Levy
WCWarren Christian
Warren Christian
Maternal address information captured on birth records is increasingly used to estimate residential environmental exposures during pregnancy. However, there has been limited assessment of the geocoding precision of birth records, particularly since the adoption of the 2003 standard birth certificate in 2015. To address this gap, this study evaluated the geocoding precision of live and stillbirth records of Kentucky residents over ten years, from 2008 through 2017. This study summarized the demographic characteristics of imprecisely geocoded records and, using a bivariate logistic regression, identified covariates associated with poor geocoding precision among three population density designations-metro, non-metro, and rural. We found that in metro areas, after adjusting for area deprivation, education, and the race, age and education of both parents, records for Black mothers had 48% lower odds of imprecise geocoding (aOR=0.52, 95% CI: 0.48, 0.56), while Black women in rural areas had 96% higher odds of imprecise geocoding (aOr=1.96, 95% CI: 1.68, 2.28). This study also found that over the study period, rural and non-metro areas began with a high proportion of imprecisely geocoded records (38% in rural areas, 19% in non-metro), but both experienced an 8% decline in imprecisely geocoded records over the study period (aOr=0.92, 95% CI: 0.92, 0.94). This study shows that, while geocoding precision has improved in Kentucky, further work is needed to improve geocoding in rural areas and address racial and ethnic disparities.

19 June 2023 in BMC Pregnancy and Childbirth
Verified
Journal Article
Open access
PDF file
CWCourtney Walker
Courtney Walker
AKAnna M. Kucharska-Newton
Anna M. Kucharska-Newton
SBSteven R. Browning
Steven R. Browning
WCW. Jay Christian
W. Jay Christian
Background: Early-onset hypertensive disorders of pregnancy (eHDP) are associated with more severe maternal and infant outcomes than later-onset disease. However, little has been done to evaluate population-level trends. Therefore, in this paper, we seek to address this understudied area by describing the geospatial and temporal patterns of county-level incidence of eHDP and assessing county-level demographics that may be associated with an increased incidence of eHDP. Methods: Employing Kentucky certificates of live and stillbirth from 2008–2017, this ecological study detected county-level clusters of early-onset hypertensive disorders of pregnancy using SaTScan, calculated average annual percent change (AAPC) with a join point analysis, and identified county-level covariates (% of births to women ≥ 35 years of age, % with BMI ≥ 30 kg/m2, % currently smoking, % married, and % experienced eHDP) with a fixed-effects negative binomial regression model for longitudinal data with an autoregressive (AR) correlation structure offset with the natural log of the number of births in each county and year. Results: County-level incidence of eHDP had a non-statistically significant increase of almost 3% (AAPC: 2.84, 95% CI: -4.26, 10.46), while maternal smoking decreased by almost 6% over the study period (AAPC:-5.8%, 95%CI: -7.5, -4.1), Risk factors for eHDP such as pre-pregnancy BMI ≥ 30 and proportion of births to women ≥ 35 years of age increased by 2.3% and 3.4% respectively (BMI AAPC:2.3, 95% CI: 0.94, 3.7; ≥ 35 years AAPC:3.4, 95% CI: 0.66, 6.3). After adjusting for race, county-level proportions of college attainment, and maternal smoking throughout pregnancy, counties with the highest proportion of births to women with BMI ≥ 30 kg/m2 reported an eHDP incidence 20% higher than counties with a lower proportion of births to mothers with a BMI ≥ 30 kg/m2 and a 20% increase in eHDP incidence (aRR = 1.20, 95% CI: 1.00, 1.44). We also observed that counties with the highest proportion vs. the lowest of mothers ≥ 35 years old (> 6.1%) had a 26% higher incidence of eHDP (RR = 1.26, 95%CI: 1.04, 1.50) compared to counties with the lowest incidence (< 2.5%). We further identified two county-level clusters of elevated eHDP rates. We also observed that counties with the highest vs. lowest proportion of mothers ≥ 34 years old (> 6.1% vs. < 2.5%) had a 26% increase in the incidence of eHDP (RR = 1.26, 95% CI: 1.04, 1.50). We further identified two county-level clusters of elevated incidence of eHDP. Conclusions: This study identified two county-level clusters of eHDP, county-level covariates associated with eHDP, and that while increasing, the average rate of increase for eHDP was not statistically significant. This study also identified the reduction in maternal smoking over the study period and the concerning increase in rates of elevated pre-pregnancy BMI among mothers. Further work to explore the population-level trends in this understudied pregnancy complication is needed to identify community factors that may contribute to disease and inform prevention strategies.