Biomedical subjects

Nancy Dole

Publications and source records attributed to Nancy Dole.

At least 19 recordsLinked to original sources

PubMed2006

Patterns of salivary cortisol secretion in pregnancy and implications for assessment protocols.

Cortisol is used in research as a biomarker of psychological stress. Logistical considerations argue for collecting as few samples as possible, balanced against diurnal rhythms and intra-individual variations. 100 pregnant women gave five saliva samples a day for 3 days, at waking, 30 min after waking, and 11:00 a.m., 5:00 p.m., and 9:00 p.m. Timing of collection was confirmed by monitors. Another sample was taken during a clinic visit. Using the 15 measures as the gold standard, correlations and mean area under the curve (AUC) were compared with subsets and the single clinic sample to evaluate alternate collection protocols. Five samples in 1 day, or protocols involving morning and night samples, had the highest correlations with mean AUC (correlation coefficient ranging from 0.82 to 0.88). Standardizing the clinic measurement to a single time of day did not substantially improve correlations with mean AUC. Correlations with measures of reported stress were also not strong.

Adult↗

PubMed2006

Violent crime exposure classification and adverse birth outcomes: a geographically-defined cohort study.

BACKGROUND: Area-level socioeconomic disparities have long been associated with adverse pregnancy outcomes. Crime is an important element of the neighborhood environment inadequately investigated in the reproductive and public health literature. When crime has been used in research, it has been variably defined, resulting in non-comparable associations across studies. METHODS: Using geocoded linked birth record, crime and census data in multilevel models, this paper explored the relevance of four spatial violent crime exposures: two proximal violent crime categorizations (count of violent crime within a one-half mile radius of maternal residence and distance from maternal residence to nearest violent crime) and two area-level crime categorizations (count of violent crimes within a block group and block group rate of violent crimes) for adverse birth events among women in living in the city of Raleigh NC crime report area in 1999-2001. Models were adjusted for maternal age and education and area-level deprivation. RESULTS: In black and white non-Hispanic race-stratified models, crime characterized as a proximal exposure was not able to distinguish between women experiencing adverse and women experiencing normal birth outcomes. Violent crime characterized as a neighborhood attribute was positively associated with preterm birth and low birth weight among non-Hispanic white and black women. No statistically significant interaction between area-deprivation and violent crime category was observed. CONCLUSION: Crime is variably categorized in the literature, with little rationale provided for crime type or categorization employed. This research represents the first time multiple crime categorizations have been directly compared in association with health outcomes. Finding an effect of area-level violent crime suggests crime may best be characterized as a neighborhood attribute with important implication for adverse birth outcomes.

Analysis of Variance↗

PubMed2006

Direct observation of neighborhood attributes in an urban area of the US south: characterizing the social context of pregnancy.

BACKGROUND: Neighborhood characteristics have been associated with poor maternal and child health outcomes, yet conceptualization of potential mechanisms is still needed. Census data have long served as proxies for area level socioeconomic influences. Unique information captured by neighborhood inventories, mostly conducted in northern US and Canadian urban areas, has shown important aspects of the community environment that are not captured by the socioeconomic and demographic aggregated individual statistics of census data. In this paper, we describe a neighborhood data collection effort tailored to a southern urban area. METHODS: This study used data from the Pregnancy, Nutrition and Infection (PIN) prospective cohort study to describe neighborhoods where low- and moderate-income pregnant women reside. Women who participated in the PIN study and who resided in Raleigh, NC and its surrounding suburbs were included (n = 703). Neighborhood attributes captured by the inventory included litter, housing condition, road condition, and social interactions that informed theoretical constructs of physical incivility, territoriality and social spaces. US Housing and Population Census 2000 data at the block group level were also assessed to identify the unique contribution of directly observed data. We hypothesize that neighborhood environments can influence health through psychosocial mediated pathways that lead to increased stress, or through disadvantage leading to poor neighborhood resources, or by protective attributes through increased social control. RESULTS: Findings suggest that directly observed neighborhood attributes distinguished between different types of areas in which low-income pregnant non-Hispanic white and non-Hispanic black women lived. Theoretically informed scales of physical incivilities, territoriality and social spaces were constructed and found to be internally consistent. Scales were weakly associated indicating that these constructs capture distinct information about these neighborhoods. Physical incivilities, territoriality and social spaces scales were poorly explained by traditional census variables used to proxy neighborhood environment. CONCLUSION: If neighborhoods influence health through psychosocial mediated pathways then careful detailing of neighborhood attributes that contribute to stress or deterioration, beyond traditional socioeconomic status, are needed. We believe that measuring physical incivility, territoriality and social spaces as expressions of underlying issues of maintenance and social communication make important contributes to this field.

Adolescent↗

PubMed2006

Psychosocial factors and socioeconomic indicators are associated with household food insecurity among pregnant women.

Household food insecurity has been associated with several negative health outcomes, yet little is known about the prevalence and correlates of household food insecurity during pregnancy. This study was conducted as part of the Pregnancy, Infection, and Nutrition prospective cohort study to identify risk factors of preterm birth. The USDA 18-item scale was used to assess the prevalence of food insecurity among pregnant women with incomes <or= 400% of poverty. Descriptive statistics and logistic regression were used to identify socioeconomic, demographic, and psychosocial predictors of household food insecurity. Among 606 pregnant women, 75% were from fully food-secure, 15% from marginally food-secure, and 10% from food-insecure households. Women from marginally food-secure and food-insecure households had significantly less income, less education, and were older than women from fully food-secure households. In bivariate analysis, all psychosocial factors were significantly associated with household food insecurity and showed a dose-response relation with increasing food insecurity. Socioeconomic and demographic predictors for household food insecurity were income, black race, and age. After controlling for socioeconomic and demographic variables, psychosocial indicators of perceived stress, trait anxiety, and depressive symptoms, and a locus of control attributed to chance were positively associated with any household food insecurity. Conversely, self-esteem and mastery were inversely associated with any household food insecurity. Psychosocial factors as well as socioeconomic and demographic indicators are associated with household food insecurity among pregnant women; however, the direction of causation between psychosocial indicators and food insecurity cannot be determined in these data.

Adolescent↗

PubMed2006

Attitudes toward participation in a pregnancy and child cohort study.

While epidemiological studies aim for high participation rates, it is becoming increasingly difficult to recruit and retain participants in lengthy observational studies. We surveyed women who recently participated in the Pregnancy, Infection, and Nutrition Study during their pregnancy to learn more about what initially motivated them to participate in the study, their attitudes about the study protocol, and whether they would allow their child to participate in future studies. Most women were motivated by their interest in science and learning about their pregnancy. In general, women felt quite comfortable with most aspects of the study. Consent forms, telephone interviews and self-administered questionnaires were the most acceptable components of the study, but even specimen collection was well tolerated by this cohort. Women were less comfortable with the possibility of their child participating in future research. This survey confirmed that once women are enrolled, they tend to be willing to complete most components of an intensive study, suggesting that initial efforts for recruitment are most important.

Adult↗

PubMed2006

Methodologic issues in the design and analysis of epidemiologic studies of pregnancy outcome.

Using epidemiology to elucidate the causes of adverse pregnancy outcomes offers unique opportunities and poses distinctive challenges. The context of pregnancy includes contraception and planning, medical interventions altering the natural history, and the tendency for selective participation in demanding research protocols. Several key pervasive issues are considered in detail: 1) the close temporal proximity of determinants and outcomes, which makes separation of causes and effects difficult and introduces the real possibility of reverse causality; 2) non-random allocation of exposure, often done consciously in response to concerns about having a healthy pregnancy or to the health of the pregnancy itself, making confounding a major concern; 3) heterogeneity of pregnancy outcomes, with endpoints such as pregnancy loss and preterm birth arising through diverse pathways that are not easily identified and if grouped, could diminish the magnitude of observed associations; and 4) racial and ethnic disparities, which pose a public health challenge in the USA and offer a potentially important opportunity for identifying preventable causes of adverse pregnancy outcome. Sophisticated biological and statistical methods are needed to advance epidemiologic research in this area.

Epidemiologic Studies↗

PubMed2005

Neighborhood crime, deprivation, and preterm birth.

PURPOSE: Significant racial disparity in preterm birth (PTB; birth at <37 weeks' gestation) exists, poorly explained by Individual-level factors. This research explores whether neighborhood crime contributes to the racial disparity in PTB. METHODS: Geocoded Wake County, NC, birth records and crime-report data for 1999 to 2001 were merged with US Census data (2000). Race-stratified logistic and multilevel logistic models produced odds ratios (ORs) and 95% confidence intervals (CIs) for block-group violent, theft, property, and vice crime rates and singleton PTB. RESULTS: A total of 13,960 women resided in a 114-block-group crime area. Non-Hispanic black women were more likely than non-Hispanic white women to deliver preterm (12.8% versus 6.7%), live in economically deprived block groups (42.2% versus 19.3% in the highest deprivation quartile), and experience more crime (32.0% versus 3.8% in the highest violent-crime-rate quartile). Quartiles of violent, theft, property, and vice crimes were associated with PTB in unadjusted models. Living in very high violent-crime-rate block-group quartiles was suggestive of increased odds of PTB for white and black non-Hispanic women (OR = 1.5; 95% CI, 0.9-2.6; and OR = 1.4; 95% CI, 1.0-2.1, respectively) in adjusted models. Other crime effects were attenuated after adjustment. CONCLUSIONS: Differential neighborhood exposures may contribute to racial disparity in PTB.

Adolescent↗

PubMed2005

Pregnancy intendedness, maternal psychosocial factors and preterm birth.

OBJECTIVES: This study examined associations between reported pregnancy intendedness and several maternal psychosocial factors in relation to preterm birth (<37 weeks' completed gestation). METHODS: Women were recruited into a prospective cohort study between the 24th and 29th weeks of pregnancy in central North Carolina from 1996 to 2000. Prior to delivery, participants responded to questions about pregnancy intendedness, life events impacts, depressive symptoms, and coping style. RESULTS: Women who reported not intending their pregnancy had increased odds of reporting low, medium and high levels of perceived stress during pregnancy (OR = 1.4 [95% CI: 1.1, 1.9], OR = 2.2 [95% CI: 1.7, 2.8], and OR = 3.4 [95% CI: 2.6, 4.5], respectively, relative to very low), medium and high levels of depressive symptoms (OR = 2.2 [95% CI: 1.8, 2.9] and OR = 3.1 [95% CI: 2.4, 3.9], respectively), and medium and high levels of several coping styles. Reporting not intending the pregnancy was not associated with increased risk of preterm birth (Risk Ratio [RR] = 1.0, 95% CI: 0.8, 1.1), but reporting the highest quartile of perceived stress (RR = 1.6, 95% CI: 1.1, 2.3) and the highest tertile of distancing coping style (compared with lowest quartile) was associated with preterm birth (RR = 1.4, 95% CI: 1.1, 1.9). Interactions between pregnancy intendedness and the psychosocial variables perceived stress, depression or coping style did not modify the psychosocial variable's associations with preterm birth. CONCLUSIONS: Pregnancy intendedness remains an important concept in the reproductive health literature integrally tied to indicators of maternal mental health, but not necessarily to pregnancy outcomes.

Adaptation, Psychological↗

PubMed2005

Should spontaneous and medically indicated preterm births be separated for studying aetiology?

An increasing proportion of preterm births result from medical interventions, and the practice of aggregating all preterm births vs. splitting into spontaneous and medically indicated preterm births is inconsistent. While mechanistic and clinical arguments can be offered for either approach, we empirically evaluated the predictiveness of a range of risk factors for preterm birth in the Pregnancy, Infection, and Nutrition Study. Most influences were shared across the two subsets - African-American ethnicity, advancing age, delivery at a university medical centre, prior preterm birth and smoking. Medically indicated preterm births appeared to be associated with intensity of medical care, higher in the university medical centre and lower for the poorest women. Body mass index was positively associated with medically indicated preterm birth and inversely with spontaneous preterm birth. Given the complexity of the aetiological pathways, both aggregation and disaggregation are well justified and should be included in studies of the causes of preterm birth.

Adult↗

PubMed2005

Probability samples of area births versus clinic populations for reproductive epidemiology studies.

Studies of pregnancy outcome are generally based either on geographically defined populations, often from birth records, or on clinic or hospital populations. We compared women recruited into a clinic-based study, the Pregnancy, Infection, and Nutrition (PIN) Study, with women who resided in the geographical area of the study (Alamance, Orange, and Wake Counties in North Carolina) and gave birth over the corresponding time period (1996-2000). Clinic participants were more likely to be Black, younger, have lower education, be unmarried, have a more frequent history of adverse pregnancy outcome, obtain prenatal care later, and smoke more cigarettes. Despite that profile, the proportion of clinic participants delivering preterm was somewhat lower than among area women overall (10.8% vs. 11.3%). Black/White risk ratios for preterm birth were markedly different for area (1.6) vs. clinic women (1.1), whereas other predictors were similar. Patterns may differ across groups for many reasons, including self-selection of clinics and varying clinical practices.

Adult↗

PubMed2005

Predictors of vaginal bleeding during the first two trimesters of pregnancy.

This study evaluates maternal age, race, cigarette smoking, prior spontaneous abortion, prior induced abortion, and prior preterm birth in relation to vaginal bleeding during the first two trimesters of pregnancy. Information on vaginal bleeding and predictors came from the Pregnancy, Infection, and Nutrition Study, which enrolled 2806 pregnant women at 24-29 weeks' gestation during 1995-2000 in central North Carolina, USA. Generalised estimating equations were applied to take into account repeated episodes of vaginal bleeding during pregnancy. Women with advanced maternal age and passive smoking exposure were more likely to experience more intense vaginal bleeding during pregnancy, as were women with prior preterm birth. More intense bleeding was also more likely to be reported among women with multiple prior spontaneous abortions or multiple prior induced abortions, but not among women with a single prior spontaneous or induced abortion. The combination of prior spontaneous and induced abortion showed a dose-response association with the occurrence of vaginal bleeding during pregnancy.

Abortion, Habitual↗

PubMed2004

Vaginal bleeding during pregnancy and preterm birth.

This study investigated the relation between self-reported vaginal bleeding during pregnancy and preterm birth in a prospective cohort of 2,829 pregnant women enrolled from prenatal clinics between 1995 and 2000 in central North Carolina. The overall association between vaginal bleeding and preterm birth was modest (risk ratio (RR) = 1.3, 95% confidence interval (CI): 1.1, 1.6). Bleeding in the first trimester only was associated with earlier preterm birth (< or =34 weeks' gestation) (RR = 1.6, 95% CI: 1.1, 2.4) and preterm birth due to preterm premature rupture of the membranes (PPROM) (RR = 1.9, 95% CI: 1.1, 3.3). Bleeding in both trimesters was associated with preterm birth due to preterm labor (RR = 3.6, 95% CI: 1.9, 6.8). Bleeding of multiple episodes, on multiple days, and with more total blood loss was associated with an approximate twofold increased risk of earlier preterm birth, PPROM, and preterm labor. In contrast, bleeding in the second trimester only, of a single episode, on a single day, and with less total blood loss was not associated with any category of preterm birth. Vaginal bleeding was not associated with preterm birth among African Amercians (RR = 1.2, 95% CI: 0.9, 1.7). This study indicates that more intense but not less intense bleeding is associated with earlier preterm birth and spontaneous preterm birth presenting as PPROM or preterm labor, and it suggests that bleeding is less predictive of preterm birth among African-American compared with White women.

Adult↗

PubMed2004

Modeling the effects of a bidirectional latent predictor from multivariate questionnaire data.

Researchers often measure stress using questionnaire data on the occurrence of potentially stress-inducing life events and the strength of reaction to these events, characterized as negative or positive and assigned an ordinal ranking. In studying the health effects of stress, one needs to obtain measures of an individual's negative and positive stress levels to be used as predictors. Motivated by data of this type, we propose a latent variable model, which is characterized by event-specific negative and positive reaction scores. If the positive reaction score dominates the negative reaction score for an event, then the individual's reported response to that event will be positive, with an ordinal ranking determined by the value of the score. Measures of overall positive and negative stress can be obtained by summing the reactivity scores across the events that occur for an individual. By incorporating these measures as predictors in a regression model and fitting the stress and outcome models jointly using Bayesian methods, inferences can be conducted without the need to assume known weights for the different events. We propose an MCMC algorithm for posterior computation and apply the approach to study the effects of stress on preterm delivery.

Algorithms↗

PubMed2004

Pregnancy-related weight gain--a link to obesity?

Past research on maternal weight gain during pregnancy has focused on determinants and consequences of inadequate weight gain with concerns for the health of the infant. However, with the rising prevalence of obesity among women of childbearing ages and the high proportion of women who are gaining in excess of recommendations, a shift in research focus must occur to include consideration of the mother's long-term health status. The few studies that have examined determinants of excessive weight gain and postpartum weight retention in this country were not comprehensive in assessing diet, physical activity and psychosocial factors and suffer from small sample sizes. Information is lacking concerning pregnant women's perceptions about eating and gaining weight, what they actually eat, how consumption and exercise relate to weight gain, and how psychosocial factors influence these behaviors during pregnancy. Likewise, little is known concerning these same attitudes and behaviors during the postpartum period that may contribute to weight retention.

Adult↗

PubMed2004

Psychosocial factors and preterm birth among African American and White women in central North Carolina.

OBJECTIVES: We assessed associations between psychosocial factors and preterm birth, stratified by race in a prospective cohort study. METHODS: We surveyed 1898 women who used university and public health prenatal clinics regarding various psychosocial factors. RESULTS: African Americans were at higher risk of preterm birth if they used distancing from problems as a coping mechanism or reported racial discrimination. Whites were at higher risk if they had high counts of negative life events or were not living with a partner. The association of pregnancy-related anxiety with preterm birth weakened when medical comorbidities were taken into account. No association with preterm birth was found for depression, general social support, or church attendance. CONCLUSIONS: Some associations between psychosocial variables and preterm birth differed by race.

Adaptation, Psychological↗

PubMed2004

Poverty, education, race, and pregnancy outcome.

Few studies have considered the differing impact of socioeconomic factors on pregnancy outcomes among racial subgroups. We assessed pregnancy outcome by race, education, and income (poverty index), using data from the Pregnancy, Infection, and Nutrition Study, a cohort study of preterm birth in central North Carolina, using binomial regression. Poverty was associated with an increased risk of preterm birth only among African Americans with 12 or more years of education (RR=1.6, 95% CI: 1.1, 2.2). White participants with both a low level of education and an income below the poverty line were at increased risk of preterm birth (RR=1.7, 95% CI: 1.1, 2.7). White women with 12 or more years of education had increased risk of small-for-gestational-age birth (SGA, defined as <10th percentile of birth weight for gestational age) associated with poverty status (RR=1.7, 95% CI: 1.1, 2.7). Socioeconomic indicators appear to have complex joint effect patterns among racial subgroups, perhaps because the material and psychological implications of education and income status differ between groups.

Adult↗

PubMed2003

Modeling community-level effects on preterm birth.

PURPOSE: We demonstrate modeling of community-level socioeconomic influences on risk of preterm birth (< 37 weeks gestation) in the Pregnancy, Infection, and Nutrition (PIN) Study. METHODS: Community-level information from the US Census was linked to 930 White and 817 African-American (Black) participants from a prospective cohort in central North Carolina through geocoded addresses, providing 123 census tracts with community-level and individual-level data for multi-level statistical analyses. RESULTS: Preterm delivery was experienced by 12.1% of Black and 10.4% of White participants. No appreciable aggregation of risk by community was discernable for White women. For Black women, random-coefficient logistic regression tract-specific preterm prevalence estimates ranged from 10.1% to 14.5%, "shrunk" from observed prevalences of 0% to 100%. Adding tract-level variables to the model representing median splits for household income and percent of single women heads of households with dependents, adjusting for individual-level maternal age and household income, accounted for much of the remaining between-tracts variation. CONCLUSIONS: Residing in a wealthier tract (> $30,000/year median income) was associated with reduced risk for Black women, adjusted OR = 0.59 (95% CI: 0.36, 0.96). The estimated conditional effect of lower community prevalence of female headed households was OR = 0.71 (95% CI: 0.43, 1.17).

Adolescent↗

PubMed2002

Indicators of cocaine exposure and preterm birth.

OBJECTIVE: To identify predictors of cocaine exposure during pregnancy, using hair and urine assays and self-report, and the association with preterm birth. METHODS: A nested case-control study was conducted in a cohort of 2611 black and white women enrolled in prenatal care in central North Carolina. Cocaine exposure was ascertained by self-report (263 cases, 612 controls), urine assays at 24-29 weeks' gestation (226 cases, 564 controls) and postpartum (160 cases, 408 controls), and postpartum hair assays (169 cases, 435 controls). The major metabolite of cocaine, benzoylecgonine, was measured in urine. Cocaine and benzoylecgonine were measured in hair. RESULTS: Cocaine exposure was identified in 2% based on self-report, 5-6% based on urine assays, and 13-15% based on hair assays. Black ethnicity, lower education, and poverty were strongly predictive of positive hair assays. Hair cocaine and benzoylecgonine were not associated with preterm birth, with the possible exception of higher levels of cocaine and benzoylecgonine and birth before 34 weeks' completed gestation. The urine screen at 24-29 weeks' gestation also gave some indication of a possible association (odds ratio 1.7, 95% confidence interval 0.9, 3.5). CONCLUSION: The study corroborates the incompleteness of cocaine exposure assessment by self-report and urine screens relative to hair assays. The strong demographic predictors of exposure suggest where intervention efforts should be targeted. The most sensitive markers of exposure, hair cocaine and benzoylecgonine, are not associated with preterm birth, perhaps because they reflect different patterns of cocaine exposure than the other measures.

Case-Control Studies↗