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ABSTRACT: Knowledge of patterns in prevalence of congenital heart defects (CHDs) is important for clinical care, etiologic research, and prevention. We evaluated temporal and racial/ethnic trends in the birth prevalence of CHDs in metropolitan Atlanta from 1978 to 2005.
Cases of CHDs were obtained from the Metropolitan Atlanta Congenital Defects Program among live born infants, stillborn infants, and pregnancy terminations of at least 20 weeks gestation. We calculated birth prevalence per 10,000 live births and used joinpoint regression analysis to calculate the average annual percent change for total CHDs and for 23 specific subtypes in the total population and among whites and blacks. To evaluate racial/ethnic variations, we calculated prevalence ratios among blacks and Hispanics compared with whites.
Between 1978 and 2005, 7301 infants and fetuses with major structural CHDs were ascertained among 1,079,062 live births (67.7 per 10,000). The prevalence of all CHDs in aggregate increased from 50.3 per 10,000 in 1978-1983 to 86.4 per 10,000 in 2000-2005. The prevalence of septal defects and vascular rings increased and the prevalence of tricuspid atresia decreased, while other CHD prevalences were stable. Racial/ethnic prevalence differences were found for all CHDs combined and muscular ventricular septal defects, aortic stenosis, and atrioventricular septal defects.
The prevalence of total CHDs, primarily common, less severe types, are increasing, with some racial/ethnic differences. Further studies could clarify the possible reasons for such variations including differences in ascertainment, risk factors, or susceptibility. Birth Defects Research (Part A) 2013. © 2013 Wiley Periodicals, Inc.
Birth Defects Research Part A Clinical and Molecular Teratology 02/2013; 97(2):87-94. · 2.27 Impact Factor
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Philip J Lupo,
Elaine Symanski,
Peter H Langlois,
Christina C Lawson,
Sadia Malik, Suzanne M Gilboa,
Laura J Lee,
A J Agopian,
Tania A Desrosiers,
Martha A Waters,
Paul A Romitti,
Adolfo Correa,
Gary M Shaw,
Laura E Mitchell
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ABSTRACT: BACKGROUND:There is evidence in experimental model systems that exposure to polycyclic aromatic hydrocarbons (PAHs) results in congenital heart defects (CHDs); however, to our knowledge, this relationship has not been examined in humans. Therefore, we conducted a case-control study assessing the association between estimated maternal occupational exposure to PAHs and CHDs in offspring. METHODS:Data on CHD cases and control infants were obtained from the National Birth Defects Prevention Study for the period of 1997 to 2002. Exposure to PAHs was assigned by industrial hygienist consensus, based on self-reported maternal occupational histories from 1 month before conception through the third month of pregnancy. Logistic regression was used to evaluate the association between maternal occupational PAH exposure and specific CHD phenotypic subtypes among offspring. RESULTS:The prevalence of occupational PAH exposure was 4.0% in CHD case mothers (76/1907) and 3.6% in control mothers (104/2853). After adjusting for maternal age, race or ethnicity, education, smoking, folic acid supplementation, and study center, exposure was not associated with conotruncal defects (adjusted odds ratio [AOR], 0.98; 95% confidence interval [CI], 0.58-1.67), septal defects (AOR, 1.28; 95% CI, 0.86-1.90), or with any isolated CHD subtype. CONCLUSIONS:Our findings do not support an association between potential maternal occupational exposure to PAHs and various CHDs in a large, population-based study. For CHD phenotypic subtypes in which modest nonsignificant associations were observed, future investigations could be improved by studying populations with a higher prevalence of PAH exposure and by incorporating information on maternal and fetal genotypes related to PAH metabolism. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Birth Defects Research Part A Clinical and Molecular Teratology 09/2012; · 2.27 Impact Factor
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ABSTRACT: Birth defects are a leading cause of infant mortality in the United States. Previous reports have highlighted black-white differences in overall infant mortality and infant mortality attributable to birth defects (IMBD). We evaluated the impact of gestational age on US racial/ethnic differences in IMBD.
We estimated the rate of IMBD as the underlying cause of death using the period-linked birth/infant death data for US residents for January 2003 to December 2006. We excluded infants with missing gestational age, implausible values based on Alexander's index of birth weight for gestational age norms, or gestational ages <20 weeks or >44 weeks; we categorized gestational age into 3 groups: 20 to 33, 34 to 36, and 37 to 44 weeks. Using Poisson regression, we compared neonatal and postneonatal IMBD for infants of non-Hispanic black and Hispanic mothers with that for infants of non-Hispanic white mothers stratified by gestational age.
IMBD occurred in 12.2 per 10 000 live births. Among infants delivered at 37 to 44 weeks, blacks (and Hispanics, to a lesser degree) had significantly higher neonatal and postneonatal IMBD than whites; however, among infants delivered at 20 to 33 or 34 to 36 weeks, neonatal (but not postneonatal) IMBD was significantly lower among blacks compared with whites.
Racial/ethnic differences in IMBD were not explained in these data by differences in gestational age. Further investigation should include an assessment of possible racial/ethnic differences in severity and/or access to timely diagnosis and management of birth defects.
PEDIATRICS 08/2012; 130(3):e518-27. · 4.47 Impact Factor
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ABSTRACT: To examine the relation between congenital heart defects (CHDs) in offspring and estimated maternal occupational exposure to chlorinated solvents, aromatic solvents and Stoddard solvent during the period from 1 month before conception through the first trimester.
The study population included mothers of infants with simple isolated CHDs and mothers of control infants who delivered from 1997 through 2002 and participated in the National Birth Defects Prevention Study. Two methods to assess occupational solvent exposure were employed: an expert consensus-based approach and a literature-based approach. Multiple logistic regression was used to calculate adjusted ORs and 95% CIs for the association between solvent classes and CHDs.
2951 control mothers and 2047 CHD case mothers were included. Using the consensus-based approach, associations were observed for exposure to any solvent and any chlorinated solvent with perimembranous ventricular septal defects (OR 1.6, 95% CI 1.0 to 2.6 and OR 1.7, 95% CI 1.0 to 2.8, respectively). Using the literature-based approach, associations were observed for: any solvent exposure with aortic stenosis (OR 2.1, 95% CI 1.1 to 4.1) and Stoddard solvent exposure with d-transposition of the great arteries (OR 2.0, 95% CI 1.0 to 4.2), right ventricular outflow tract obstruction defects (OR 1.9, 95% CI 1.1 to 3.3) and pulmonary valve stenosis (OR 2.1, 95% CI 1.1 to 3.8).
The authors found evidence of associations between occupational exposure to solvents and several types of CHDs. These results should be interpreted in light of the potential for misclassification of exposure.
Occupational and environmental medicine 07/2012; 69(9):628-35. · 3.64 Impact Factor
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ABSTRACT: OBJECTIVE: The objective of this study was to evaluate the association between the use of monotherapy topiramate in pregnancy and cleft lip with or without cleft palate (CL/P) in the offspring. STUDY DESIGN: Data from the Slone Epidemiology Center Birth Defects Study (BDS) from 1997 to 2009 and the National Birth Defects Prevention Study (NBDPS) from 1997 to 2007 were analyzed. Conditional logistic regression was used to compare the first-trimester use of topiramate monotherapy to no antiepileptic drug use during the periconceptional period between the mothers of infants with CL/P and the mothers of controls for each study separately and in pooled data. RESULTS: The BDS contained 785 CL/P cases and 6986 controls; the NBDPS contained 2283 CL/P cases and 8494 controls. The odds ratios (exact 95% confidence intervals) for the association between topiramate use and CL/P were 10.1 (1.1-129.2) in the BDS, 3.6 (0.7-20.0) in the NBDPS, and 5.4 (1.5-20.1) in the pooled data. CONCLUSION: First-trimester use of topiramate may be associated with CL/P.
American journal of obstetrics and gynecology 07/2012; · 3.28 Impact Factor
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ABSTRACT: The purpose of this study was to examine the risk of birth defects in relation to diabetes mellitus and the lack of use of periconceptional vitamins or supplements that contain folic acid.
The National Birth Defects Prevention Study (1997-2004) is a multicenter, population-based case-control study of birth defects (14,721 cases and 5437 control infants). Cases were categorized into 18 types of heart defects and 26 noncardiac birth defects. We estimated odds ratios for independent and joint effects of preexisting diabetes mellitus and a lack of periconceptional use of vitamins or supplements that contain folic acid.
The pattern of odds ratios suggested an increased risk of defects that are associated with diabetes mellitus in the absence vs the presence of the periconceptional use of vitamins or supplements that contain folic acid.
The lack of periconceptional use of vitamins or supplements that contain folic acid may be associated with an excess risk for birth defects due to diabetes mellitus.
American journal of obstetrics and gynecology 03/2012; 206(3):218.e1-13. · 3.28 Impact Factor
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ABSTRACT: In 2005, a pilot project was started at the Centers for Disease Control and Prevention (CDC) to expand an existing birth defects surveillance program, the Metropolitan Atlanta Congenital Defects Program (MACDP), to conduct active surveillance of stillbirth. This pilot project was evaluated using CDC's current guidelines for evaluating surveillance systems.
We conducted stakeholder interviews with the staff of MACDP's stillbirth surveillance system. We reviewed the published literature on stillbirth ascertainment including 4 previous publications about the MACDP stillbirth surveillance system. Using fetal death certificates (FDC) as a second, independent data source, we estimated the total number and prevalence of stillbirths in metropolitan Atlanta using capture-recapture methods, and calculated the sensitivity of the MACDP stillbirth surveillance system.
The MACDP stillbirth surveillance system is useful, flexible, acceptable, and stable. The system's data quality is improved because it uses multiple sources for case ascertainment. Based on 2006 data, estimated sensitivities of FDCs, MACDP, and both sources combined for identifying a stillbirth were 78.5%, 76.8%, and 95.0%, respectively. The prevalence of stillbirths per 1,000 live births and stillbirths was 8.2 (95% confidence interval [CI]: 7.5-9.0) based on FDC data alone and 9.9 (95% CI: 9.1-10.8) when combined with MACDP data.
Use of MACDP as an additional data source for stillbirth surveillance resulted in higher levels of case ascertainment, better data quality, and a higher estimate of stillbirth prevalence than using FDC data alone. MACDP could be considered as a model to enhance stillbirth surveillance by other active birth defects surveillance programs.
J Registry Manag 01/2012; 39(1):13-8, quiz 36.
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ABSTRACT: To evaluate use of specific antiepileptic drugs (AEDs) in pregnancy in relation to specific birth defects.
Using data from the National Birth Defects Prevention Study, we assessed use of AEDs and the risk of neural tube defects (NTDs), oral clefts (OCs), heart defects (HDs), hypospadias, and other major birth defects, taking specific agent, timing, and indication into consideration.
Drug-specific increased risks were observed for valproic acid in relation to NTDs [adjusted odds ratio (aOR), 9.7;, 95% confidence interval (CI), 3.4-27.5], OCs (aOR, 4.4; 95% CI, 1.6-12.2), HDs (aOR, 2.0; 95% CI, 0.78-5.3), and hypospadias (aOR. 2.4; 95% CI, 0.62-9.0), and for carbamazapine in relation to NTDs (aOR, 5.0; 95% CI, 1.9-12.7). Epilepsy history without AED use did not seem to increase risk.
Valproic acid, which current guidelines suggest should be avoided in pregnancy, was most notable in terms of strength and breadth of its associations. Carbamazapine was associated with NTDs, even after controlling for folic acid use. Sample sizes were still too small to adequately assess risks of less commonly used AEDs, but our findings support further study to identify lower risk options for pregnant women.
Annals of epidemiology 11/2011; 21(11):842-50. · 2.95 Impact Factor
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ABSTRACT: Selected antiepileptic drugs (AEDs) increase the risk of birth defects. To assess the impact of influencing AED prescribing practices on spina bifida and cleft palate we searched the literature for estimates of the association between valproic acid or carbamazepine use during pregnancy and these defects and summarized the associations using meta-analyses. We estimated distributions of the prevalence of valproic acid and carbamazepine use among women of childbearing age based on analyses of four data sets. We estimated the attributable fractions and the number of children born with each defect that could be prevented annually in the United States if valproic acid and carbamazepine were not used during pregnancy. The summary odds ratio estimate for the association between valproic acid and spina bifida was 11.9 (95% uncertainty interval (UI): 4.0-21.2); for valproic acid and cleft palate 5.8 (95% UI: 3.3-9.5); for carbamazepine and spina bifida 3.6 (95% UI: 1.3-7.8); and for carbamazepine and cleft palate 2.4 (95% UI: 1.1-4.5) in the United States. Approximately 40 infants (95% UI: 10-100) with spina bifida and 35 infants (95% UI: 10-70) with cleft palate could be born without these defects each year if valproic acid were not used during pregnancy; 5 infants (95% UI: 0-15) with spina bifida and 5 infants (95% UI: 0-15) with cleft palate could be born without these defects each year if carbamazepine were not used during pregnancy. This modeling approach could be extended to other medications to estimate the impact of translating pharmacoepidemiologic data to evidence-based prenatal care practice.
American Journal of Medical Genetics Part C Seminars in Medical Genetics 08/2011; 157(3):234-46. · 4.06 Impact Factor
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ABSTRACT: The objective of the study was to provide information on overall medication use throughout pregnancy, with particular focus on the first trimester and specific prescription medications.
The study design included the Slone Epidemiology Center Birth Defects Study, 1976-2008, and the National Birth Defects Prevention Study, 1997-2003, which together interviewed more than 30,000 women about their antenatal medication use.
Over the last 3 decades, first-trimester use of prescription medication increased by more than 60%, and the use of 4 or more medications more than tripled. By 2008, approximately 50% of women reported taking at least 1 medication. Use of some specific medications markedly decreased or increased. Prescription medication use increased with maternal age and education, was highest for non-Hispanic whites, and varied by state.
These data reflect the widespread and growing use of medications by pregnant women and reinforce the need to study their respective fetal risks and safety.
American journal of obstetrics and gynecology 04/2011; 205(1):51.e1-8. · 3.28 Impact Factor
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ABSTRACT: We investigated associations between maternal cigarette smoking during the first trimester and the risk of congenital heart defects (CHDs) among the infants.
The Baltimore-Washington Infant Study was the first population-based case-control study of CHDs conducted in the United States. Case and control infants were enrolled during the period 1981-1989. We excluded mothers with overt pregestational diabetes and case mothers whose infants had noncardiac anomalies (with the exception of atrioventricular septal defects with Down syndrome) from the analysis, which resulted in 2525 case and 3435 control infants. Self-reported first-trimester maternal cigarette consumption was ascertained via an in-person interview after delivery. Associations for 26 different groups of CHDs with maternal cigarette consumption were estimated by using logistic regression models. Odds ratios (ORs) corresponded to a 20-cigarette-per-day increase in consumption.
We observed statistically significant positive associations between self-reported first-trimester maternal cigarette consumption and the risk of secundum-type atrial septal defects (OR: 1.36 [95% confidence interval (CI): 1.04-1.78]), right ventricular outflow tract defects (OR: 1.32 [95% CI: 1.06-1.65]), pulmonary valve stenosis (OR: 1.35 [95% CI: 1.05-1.74]), truncus arteriosus (OR: 1.90 [95% CI: 1.04-3.45]), and levo-transposition of the great arteries (OR: 1.79 [95% CI: 1.04-3.10]). A suggestive association was observed for atrioventricular septal defects among infants without Down syndrome (OR: 1.50 [95% CI: 0.99-2.29]).
These findings add to the existing body of evidence that implicates first-trimester maternal cigarette smoking as a modest risk factor for select CHD phenotypes.
PEDIATRICS 02/2011; 127(3):e647-53. · 4.47 Impact Factor
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ABSTRACT: Previous reports suggest that mortality resulting from congenital heart disease (CHD) among infants and young children has been decreasing. There is little population-based information on CHD mortality trends and patterns among older children and adults.
We used data from death certificates filed in the United States from 1999 to 2006 to calculate annual CHD mortality by age at death, race-ethnicity, and sex. To calculate mortality rates for individuals ≥1 year of age, population counts from the US Census were used in the denominator; for infant mortality, live birth counts were used. From 1999 to 2006, there were 41,494 CHD-related deaths and 27,960 deaths resulting from CHD (age-standardized mortality rates, 1.78 and 1.20 per 100,000, respectively). During this period, mortality resulting from CHD declined 24.1% overall. Mortality resulting from CHD significantly declined among all race-ethnicities studied. However, disparities persisted; overall and among infants, mortality resulting from CHD was consistently higher among non-Hispanic blacks compared with non-Hispanic whites. Infant mortality accounted for 48.1% of all mortality resulting from CHD; among those who survived the first year of life, 76.1% of deaths occurred during adulthood (≥18 years of age).
CHD mortality continued to decline among both children and adults; however, differences between race-ethnicities persisted. A large proportion of CHD-related mortality occurred during infancy, although significant CHD mortality occurred during adulthood, indicating the need for adult CHD specialty management.
Circulation 11/2010; 122(22):2254-63. · 14.74 Impact Factor
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ABSTRACT: The purpose of this study was to examine associations between prepregnancy body mass index (BMI) and congenital heart defects (CHDs).
These analyses included case infants with CHDs (n = 6440) and liveborn control infants without birth defects (n = 5673) enrolled in the National Birth Defects Prevention Study (1997-2004).
Adjusted odds ratios for all CHDs combined were 1.16 (95% confidence interval [CI], 1.05-1.29), 1.15 (95% CI, 1.00-1.32), and 1.31 (95% CI, 1.11-1.56) for overweight status, moderate obesity, and severe obesity, respectively. Phenotypes associated with elevated BMI (> or =25.0 kg/m(2)) were conotruncal defects (tetralogy of Fallot), total anomalous pulmonary venous return, hypoplastic left heart syndrome, right ventricular outflow tract (RVOT) defects (pulmonary valve stenosis), and septal defects (secundum atrial septal defect).
These results corroborated those of previous studies and suggested new associations between obesity and conotruncal defects and RVOT defects.
American journal of obstetrics and gynecology 09/2009; 202(1):51.e1-51.e10. · 3.28 Impact Factor
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ABSTRACT: Antihistamines are commonly used during pregnancy. There is little evidence that they have teratogenic effects, but there are knowledge gaps with respect to newer products, as well as the relationship between specific antihistamines and specific birth defects.
Using the National Birth Defects Prevention Study (1997-2003), the authors examined associations between maternal use of 14 antihistamines during early pregnancy and 26 isolated major birth defects. A Bayesian analysis incorporating prior knowledge about the relationships between antihistamines, birth defects, and measured covariates was conducted.
Of the 364 associations investigated, 24 had 95% posterior intervals excluding 1.0. All 24 associations were positive; 23 associations were of weak to moderate magnitude (posterior OR < 3.0) and one was strong (OR > 6.0) but very imprecise. Of the 24 associations, 20 were with noncardiac defects. Eight associations involved the antihistamine diphenhydramine.
The results of this study generally were consistent with no association between birth defects and antihistamine use during early pregnancy. Several of the findings might warrant further investigation, although the observed elevated associations should be interpreted in the context of the number of associations investigated and the analysis of retrospective, self-reported data.
Birth Defects Research Part A Clinical and Molecular Teratology 01/2009; 85(2):137-50. · 2.27 Impact Factor
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ABSTRACT: Advances in prenatal diagnosis have led to changes in the management of pregnancies affected with birth defects. These changes pose unique challenges for birth defects monitoring programs which use hospital-based sources.
In 1994, Metropolitan Atlanta Congenital Defects Program (MACDP) abstractors began to visit area perinatologists' offices to identify pregnancies diagnosed prenatally with fetal defects. These pregnancies were then linked with existing MACDP cases and the hospital deliveries abstracted. Those without a hospital delivery were included as having unknown outcomes. Prenatally diagnosed defects were classified as definite or possible based on the certainty of the prenatal description. For 1995-2004, we calculated minimum and maximum adjusted defect prevalences by adding definite prenatal defects, and definite plus possible prenatal defects, to the hospital-based cases.
We identified 1009 pregnancies with a prenatally diagnosed defect not ascertained from MACDP hospital sources. Including these increased the total defect prevalence from 28 per 1000 live births to a minimum of 29.94 (6.9% increase) and maximum of 30.14 (7.7% increase) per 1000. The minimum increase was greater than 50% for conjoined twins, triploidy, craniorachischisis, cystic hygroma, Klinefelter syndrome, anencephaly, Turner syndrome, and trisomies 13, 18 and 21 among mothers >or=35.
These data reflect the variety of congenital abnormalities that can be detected prenatally and the importance of including prenatal diagnoses in birth defects monitoring data. Birth defects monitoring programs should assess individually the extent to which prenatal diagnosis can affect the accuracy and completeness of their data. Birth Defects Research (Part A), 2009. Published 2008 Wiley-Liss, Inc.
Birth Defects Research Part A Clinical and Molecular Teratology 12/2008; 85(1):20-9. · 2.27 Impact Factor
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ABSTRACT: The purpose of this study was to examine associations between diabetes mellitus and 39 birth defects.
This was a multicenter case-control study of mothers of infants who were born with (n = 13,030) and without (n = 4895) birth defects in the National Birth Defects Prevention Study (1997-2003).
Pregestational diabetes mellitus (PGDM) was associated significantly with noncardiac defects (isolated, 7/23 defects; multiples, 13/23 defects) and cardiac defects (isolated, 11/16 defects; multiples, 8/16 defects). Adjusted odds ratios for PGDM and all isolated and multiple defects were 3.17 (95% CI, 2.20-4.99) and 8.62 (95% CI, 5.27-14.10), respectively. Gestational diabetes mellitus (GDM) was associated with fewer noncardiac defects (isolated, 3/23 defects; multiples, 3/23 defects) and cardiac defects (isolated, 3/16 defects; multiples, 2/16 defects). Odds ratios between GDM and all isolated and multiple defects were 1.42 (95% CI, 1.17-1.73) and 1.50 (95% CI, 1.13-2.00), respectively. These associations were limited generally to offspring of women with prepregnancy body mass index > or =25 kg/m(2).
PGDM was associated with a wide range of birth defects; GDM was associated with a limited group of birth defects.
American journal of obstetrics and gynecology 09/2008; 199(3):237.e1-9. · 3.28 Impact Factor
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ABSTRACT: Categorical analyses of prepregnancy body mass index (BMI) have shown that maternal overweight and obesity are associated with adverse pregnancy outcomes. It is unclear whether further insight into these associations can be gained from spline regression.
We used spline regression to examine the relations between prepregnancy BMI and five adverse pregnancy outcomes in the Baltimore-Washington Infant Study, a case-control study of congenital cardiac defects. Analyses included 3,226 singleton live-born control infants delivered 1981 through 1989. We modeled BMI using (a) traditional categories of underweight, average weight, overweight, and obese and (b) restricted quadratic splines.
We confirmed that overweight status and obesity were associated with increased risk of macrosomia and large for gestational age. For these outcomes, splines provided detail about the associations at the ends of the BMI distribution and within the average BMI category. Spline analyses also showed that underweight status was associated with increased risk of preterm delivery.
Analyses of traditional categories of BMI provide good understanding of the associations with several adverse birth outcomes. For three outcomes, modeling with splines provided additional insight regarding dose-response relations within categories. Results suggest the need for further analyses of average BMI and adverse pregnancy outcomes.
Annals of Epidemiology 04/2008; 18(3):196-205. · 3.21 Impact Factor
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Adolfo Correa,
Janet D Cragan,
James E Kucik,
Clinton J Alverson, Suzanne M Gilboa,
Renu Balakrishnan,
Matthew J Strickland,
C Wes Duke,
Leslie A O'Leary,
Tiffany Riehle-Colarusso,
Csaba Siffel,
Don Gambrell,
Debra Thompson,
Michael Atkinson,
Jamuna Chitra
Birth Defects Research Part A Clinical and Molecular Teratology 03/2007; 79(2):65-186. · 2.27 Impact Factor
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ABSTRACT: Our population-based case-control study of air quality and birth defects in Texas relied on the geocoding of maternal residence from vital records for the assignment of air pollution exposures during early pregnancy. We attempted to geocode the maternal addresses for 5,338 birth defect cases and 4,574 frequency-matched controls using an automated procedure with standard matching criteria in ArcGIS 8.2 and 8.3. Initially, we matched 7,266 observations (73%). To increase the proportion of successful matches, we used an interactive procedure for the 2,646 addresses that were initially not geocoded by the software. This yielded an additional 985 matches (37%). Using the same 2,646 initially unmatched addresses, we compared the results of this interactive procedure to those of an automated procedure using lower standards. The automated procedure with lower standards yielded more matches (n=1,559, 59%) but with questionable accuracy. We included the interactively geocoded observations in our final data set. Their inclusion did not affect the estimates of air pollution exposure but increased our statistical power to detect associations between air quality and risk of selected birth defects. The geocoded and not geocoded populations differed in the distribution of Latino ethnicity (51% vs 59%) and ethnicity was independently associated with air pollution exposures (P<0.05). Geocoding status also appeared to modify the association between ethnicity and risk of birth defects; Latina women appeared to have a slightly lower risk of birth defects than non-Latina women in the geocoded population and to have a slightly higher risk in the not geocoded population. Incomplete geocoding may have resulted in a selection bias because of the under-representation of Latinas in our study population.
Environmental Research 06/2006; 101(2):256-62. · 3.40 Impact Factor
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ABSTRACT: State vital records are often used to select population-based controls in record-linkage studies of birth defects. However, locating and contacting individuals based on these data sources to collect additional data can be a challenge.
A large case-control study of air quality and birth defects was conducted in 7 Texas counties in which cases were selected from the Texas Birth Defects Registry and controls from state vital records. In 2004, data from these sources were used to trace mothers of cases and controls who delivered babies in the year 2000 (n=2477) for participation in a computer-assisted telephone interview. A number of factors that predicted whether an individual would be located and interviewed were identified.
Between March and August 2004, 38% of the mothers were located, and 38% of the located mothers were interviewed. Case mothers were more likely than control mothers to be located (44 vs. 30%) and, if located, to be interviewed (43 vs. 31%). We compared the characteristics of mothers who were not located (case n=760; control n=777), mothers who were located but not interviewed (case n=344; control n=236), and mothers who were interviewed (case n=256; control n=104). Among both cases and controls, older mothers (>or=30 years) were more likely than younger mothers to be located, and non-Hispanic black mothers were least likely to be located and interviewed.
Despite the utility of vital records as a source of population-based controls in record-linkage analyses, the poor response rate discourages the use of these data sources to contact individuals for a follow-up study 4 years after delivery.
Birth Defects Research Part A Clinical and Molecular Teratology 01/2006; 76(1):60-5. · 2.27 Impact Factor
