Epidemiology beyond its limits.

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

County-Level Associations Between Pregnancy-Related Mortality Ratios and Contextual Sociospatial Indicators.

OBJECTIVE: To characterize county-level differences in pregnancy-related mortality as a function of sociospatial indicators. METHODS: We conducted a cross-sectional multilevel analysis of all pregnancy-related deaths and all live births with available ZIP code or county data in the Pregnancy Mortality Surveillance System during 2011-2016 for non-Hispanic Black, Hispanic (all races), and non-Hispanic White women aged 15-44 years. The exposures included 31 conceptually-grounded, county-specific sociospatial indicators that were collected from publicly available data sources and categorized into domains of demographic; general, reproductive, and behavioral health; social capital and support; and socioeconomic contexts. We calculated the absolute difference of county-level pregnancy-related mortality ratios (deaths per 100,000 live births) per 1-unit increase in the median absolute difference between women living in counties with higher compared with lower levels of each sociospatial indicator overall and stratified by race and ethnicity. RESULTS: Pregnancy-related mortality varied across counties and by race and ethnicity. Many sociospatial indicators were associated with county-specific pregnancy-related mortality ratios independent of maternal age, population size, and Census region. Across domains, the most harmful indicators were percentage of low-birth-weight births (absolute ratio difference [RD] 6.44; 95% CI 5.36-7.51), percentage of unemployed adults (RD 4.98; 95% CI 3.91-6.05), and food insecurity (RD 4.92; 95% CI 4.14-5.70). The most protective indicators were higher median household income (RD -2.76; 95% CI -3.28 to -2.24), percentage of college-educated adults (RD -2.28; 95% CI -2.81 to -1.75), and percentage of owner-occupied households (RD -1.66; 95% CI -2.29 to -1.03). The magnitude of these associations varied by race and ethnicity. CONCLUSION: This analysis identified sociospatial indicators of pregnancy-related mortality and showed an association between pregnancy-related deaths and place of residence overall and stratified by race and ethnicity. Understanding county-level context associated with pregnancy-related mortality may be an important step towards building public health evidence to inform action to reduce pregnancy-related mortality at local levels.

Impact of access to care and race/ethnicity on IVF care discontinuation.

RESEARCH QUESTION: Is race/ethnicity or access to care, as defined by insurance coverage, distance to the clinic and zip code (postal code), associated with care discontinuation following IVF? DESIGN: A retrospective cohort study of 878 diverse women who underwent 1571 IVF cycles from 2014 to 2018 at a Southeastern academic medical centre was performed. Women were divided into low (LAC) and high (HAC) access to care groups. HAC was defined as possessing IVF insurance coverage, living ≤25 miles from the clinic, and living in a zip code with a median income ≥$75,000. Access groups and racial/ethnic groups were compared for differences in relative risk of care discontinuation following an unsuccessful IVF cycle. RESULTS: Women with HAC had a poorer IVF prognosis than the LAC group, which possibly impacted the association with care discontinuation. Distance to the clinic, but not insurance coverage or zip code, was associated with increased risk of care discontinuation. Among women ≤34 years, HAC showed some evidence of an association with an increased risk of care discontinuation (adjusted relative risk 2.5, 95% confidence interval 0.8-8.1). Despite having higher rates of insurance coverage (51.2% versus 36.5%), non-Hispanic Black women were more likely to discontinue care (58.3% versus 40.2%) and less likely to achieve a live birth (53.0% versus 68.0%) than non-Hispanic White women. CONCLUSIONS: Identification as non-Hispanic Black, and distance to the clinic, but not insurance coverage or zip code, were associated with increased risk of care discontinuation following an unsuccessful IVF cycle. In women ≤34 years old, HAC may be associated with a higher rate of care discontinuation.

A Review of Prenatal Care Delivery to Inform the Michigan Plan for Appropriate Tailored Healthcare in Pregnancy Panel.

OBJECTIVE: To perform a literature review of key aspects of prenatal care delivery to inform new guidelines. DATA SOURCES: A comprehensive review of Ovid MEDLINE, Elsevier's Scopus, Google Scholar, and ClinicalTrials.gov. METHODS OF STUDY SELECTION: We included studies addressing components of prenatal care delivery (visit frequency, routine pregnancy assessments, and telemedicine) that assessed maternal and neonatal health outcomes, patient experience, or care utilization in pregnant individuals with and without medical conditions. Quality was assessed using the RAND/UCLA Appropriateness Methodology approach. Articles were independently reviewed by at least two members of the study team for inclusion and data abstraction. TABULATION, INTEGRATION, AND RESULTS: Of the 4,105 published abstracts identified, 53 studies met inclusion criteria, totaling 140,150 participants. There were no differences in maternal and neonatal outcomes among patients without medical conditions with reduced visit frequency schedules. For patients at risk of preterm birth, increased visit frequency with enhanced prenatal services was inconsistently associated with improved outcomes. Home monitoring of blood pressure and weight was feasible, but home monitoring of fetal heart tones and fundal height were not assessed. More frequent weight measurement did not lower rates of excessive weight gain. Home monitoring of blood pressure for individuals with medical conditions was feasible, accurate, and associated with lower clinic utilization. There were no differences in health outcomes for patients without medical conditions who received telemedicine visits for routine prenatal care, and patients had decreased care utilization. Telemedicine was a successful strategy for consultations among individuals with medical conditions; resulted in improved outcomes for patients with depression, diabetes, and hypertension; and had inconsistent results for patients with obesity and those at risk of preterm birth. CONCLUSION: Existing evidence for many components of prenatal care delivery, including visit frequency, routine pregnancy assessments, and telemedicine, is limited.

Urban-rural differences in pregnancy-related deaths, United States, 2011-2016.

BACKGROUND: The US pregnancy-related mortality ratio has not improved over the past decade and includes striking disparities by race and ethnicity and by state. Understanding differences in pregnancy-related mortality across and within urban and rural areas can guide the development of interventions for preventing future pregnancy-related deaths. OBJECTIVE: We sought to compare pregnancy-related mortality across and within urban and rural counties by race and ethnicity and age. STUDY DESIGN: We conducted a descriptive analysis of 3747 pregnancy-related deaths during 2011-2016 (the most recent available data) with available zone improvement plan code or county data in the Pregnancy Mortality Surveillance System, among Hispanic and non-Hispanic White, Black, American Indian or Alaska Native, and Asian or Pacific Islander women aged 15 to 44 years. We aggregated data by US county and grouped counties per the National Center for Health Statistics Urban-Rural Classification Scheme for Counties. We used R statistical software, epitools, to calculate the pregnancy-related mortality ratio (number of pregnancy-related deaths per 100,000 live births) for each urban-rural grouping, obtain 95% confidence intervals, and perform exact tests of ratio comparisons using the Poisson distribution. RESULTS: Of the total 3747 pregnancy-related deaths analyzed, 52% occurred in large metro counties, and 7% occurred in noncore (rural) counties. Large metro counties had the lowest pregnancy-related mortality ratio (14.8; 95% confidence interval, 14.2-15.5), whereas noncore counties had the highest (24.1; 95% confidence interval, 21.4-27.1), including race and ethnicity and age groups. Pregnancy-related mortality ratio age disparities increased with rurality. Women aged 25 to 34 years and 35 to 44 years living in noncore counties had pregnancy-related mortality ratios 1.5 and 3 times higher, respectively, than women of the same age groups in large metro counties. Within each urban-rural category, pregnancy-related mortality ratios were higher among non-Hispanic Black women than non-Hispanic White women. Non-Hispanic American Indian or Alaska Native pregnancy-related mortality ratios in small metro, micropolitan, and noncore counties were 2 to 3 times that of non-Hispanic White women in the same areas. CONCLUSION: Although more than half of pregnancy-related deaths occurred in large metro counties, the pregnancy-related mortality ratio rose with increasing rurality. Disparities existed in urban-rural categories, including by age group and race and ethnicity. Geographic location is an important context for initiatives to prevent future deaths and eliminate disparities. Further research is needed to better understand reasons for the observed urban-rural differences and to guide a multifactorial response to reduce pregnancy-related deaths.

Retrospective cohort study of COVID-19 among children in Fulton County, Georgia, March 2020-June 2021.

OBJECTIVE: To describe case rates, testing rates and percent positivity of COVID-19 among children aged 0-18 years by school-age grouping. DESIGN: We abstracted data from Georgia's State Electronic Notifiable Disease Surveillance System on all 10 437 laboratory-confirmed COVID-19 cases among children aged 0-18 years during 30 March 2020 to 6 June 2021. We examined case rates, testing rates and percent positivity by school-aged groupings, namely: preschool (0-4 years), elementary school (5-10 years), middle school (11-13 years), and high school (14-18 years) and compared these data among school-aged children with those in the adult population (19 years and older). SETTING: Fulton County, Georgia. MAIN OUTCOME MEASURES: COVID-19 case rates, testing rates and percent positivity. RESULTS: Over time, the proportion of paediatric cases rose substantially from 1.1% (April 2020) to 21.6% (April 2021) of all cases in the county. Age-specific case rates and test rates were consistently highest among high-school aged children. Test positivity was similar across school-age groups, with periods of higher positivity among high-school aged children. CONCLUSIONS: Low COVID-19 testing rates among children, especially early in the pandemic, likely underestimated the true burden of disease in this age group. Despite children having lower measured incidence of COVID-19, we found when broader community incidence increased, incidence also increased among all paediatric age groups. As the COVID-19 pandemic continues to evolve, it remains critical to continue learning about the incidence and transmissibility of COVID-19 in children.

Number of Eating Occasions and Source of Foods and Drinks Among Young Children in the United States: NHANES, 2009⁻2014.

An understanding of the source of children's foods and drinks is needed to identify the best intervention points for programs and policies aimed at improving children's diets. The mean number and type of eating occasions and the relative proportions of foods and drinks consumed from different sources were calculated among children aged 1-4 years (n = 2640) using data from the 2009-2014 National Health and Nutrition Examination Surveys. Children consumed 2.9 meals and 2.4 snacks each day. Among children who received anything from childcare, childcare provided 36.2% of their foods and drinks. The majority of foods and drinks came from stores for all children (53.2% among those receiving anything from childcare and 84.9% among those not). Among children receiving food from childcare, childcare is an important source of foods and drinks. Because most foods and drinks consumed by children come from stores, parents and caregivers may benefit from nutrition education to promote healthful choices when buying foods.

Association of Maternity Care Practices and Policies with In-Hospital Exclusive Breastfeeding in the United States.

Background: Experiences during the birth hospitalization affect breastfeeding outcomes. In the United States, hospital policies and practices supportive of breastfeeding are routinely assessed through the Maternity Practices in Infant Nutrition and Care (mPINC) survey; however, mPINC does not capture data on breastfeeding outcomes. Materials and Methods: Data from the 2015 mPINC survey were linked to 2015 data from the Joint Commission (TJC), a major accreditor of health care systems in the United States (n = 1,305 hospitals). Each hospital participating in mPINC is given a total score, which is the average of seven subscores; all ranging from 0 to 100. TJC has hospital-specific data on the percentage of infants exclusively breastfeeding at hospital discharge. We used linear regression to estimate differences between quartiles of (1) total mPINC score and (2) each mPINC subscore with rates of exclusive breastfeeding at hospital discharge, adjusting for hospital type, teaching status, and number of annual births. We additionally used linear models to test for trend across quartiles of mPINC score. Results: The mean percentage of in-hospital exclusive breastfeeding increased from 39.0% for hospitals in the lowest mPINC total score quartile (<75) to 60.4% for hospitals in the highest mPINC total score quartile (≥89), an adjusted difference of 21.1 percentage points (95% confidence interval 18.6-23.6). The mean percentage of in-hospital exclusive breastfeeding significantly increased (p < 0.0001) as mPINC scores increased for total mPINC score and for each mPINC subscore. Conclusions: Higher mPINC scores were associated with higher rates of in-hospital exclusive breastfeeding. Hospitals can make improvements to their maternity care practices and policies to support breastfeeding.

Fertility treatment use and breastfeeding outcomes.

BACKGROUND: About 15% of women aged 15-44 years in the United States experience infertility. Factors associated with infertility and fertility treatments may also be associated with lactation difficulties. Limited data exist examining the impact of infertility or mode of conception on breastfeeding outcomes. OBJECTIVE: The objectives of this study were to report breastfeeding outcomes (initiation and duration at 8 weeks) among women who conceived spontaneously compared to women who conceived using fertility treatments (assisted reproductive technology [ART], intrauterine insemination, or fertility-enhancing drugs). MATERIALS AND METHODS: Maternal-reported data from 4 states from the 2012-2015 Pregnancy Risk Assessment and Monitoring System (PRAMS) were used to explore use of fertility treatment and breastfeeding initiation and continuation at 8 weeks (n = 15,615). Data were weighted to represent all women delivering live births within each state; SAS survey procedures were used to account for PRAMS complex survey design. Stepwise, multivariable logistic regression, adjusted for maternal demographics, parity, plurality, mode of delivery, preterm birth, and maternal pre-pregnancy health conditions, was used to quantify the associations between fertility treatment use and breastfeeding. RESULTS: Mode of conception was not associated with breastfeeding outcomes when comparing women who conceived spontaneously to women who conceived using any fertility treatment. The odds of breastfeeding at 8 weeks were lower among women who conceived using ART, after adjusting for basic demographic covariates (adjusted odds ratio [aOR], 0.71; 95% confidence interval [CI], 0.52-0.97) and additionally adjusting for maternal health conditions (aOR, 0.68; 95% CI, 0.49-0.93), but this difference was no longer significant after adjusting for plurality and preterm birth (aOR, 0.74; 95% CI, 0.54-1.02). CONCLUSION: This study suggests that mothers who conceive using ART may breastfeed for shorter durations than mothers who conceive spontaneously, partially mediated by an increased likelihood of multiples and infants born preterm. Studies are needed to elucidate these associations and to understand the intentions and barriers to breastfeeding among women who conceive with the help of ART.

Trends in Maternity Care Practice Skin-to-Skin Contact Indicators: United States, 2007-2015.

BACKGROUND: Mother-infant skin-to-skin contact (SSC) immediately after birth helps transition infants to the post-uterine environment and increases the likelihood of breastfeeding initiation and duration. This study examines trends in U.S. maternity practices related to SSC, and variations by facility demographics. METHODS: Data were from the Maternity Practices in Infant Nutrition and Care (mPINC) surveys (2007-2015), a biennial assessment of all U.S. maternity facilities. Facilities reported how often patients were encouraged to practice mother-infant SSC for ≥30 minutes within 1 hour of uncomplicated vaginal birth and 2 hours of uncomplicated cesarean birth, and how often routine infant procedures are performed while in SSC. We calculated the percentage of maternity facilities reporting these indicators for ≥90% of patients across the United States for each survey year. Estimates by facility characteristics (size, type, and state) were calculated for 2015 only. RESULTS: The percentage of facilities reporting "Most (≥90%)" women, which were encouraged to practice early SSC, increased from 2007 to 2015 following both vaginal (40.4% to 83.0%) and cesarean (29.3% to 69.9%) births. The percentage of facilities reporting routine infant procedures were performed "Almost always (≥90%)," while mother and infant were SSC increased from 16.6% to 49.5% (2007 to 2015) for vaginal births and from 2.2% to 10.7% (2009 to 2015) for cesarean births. Variations in SSC practice by facility type, size, and state were noted. CONCLUSIONS: Significant progress has been made in increasing hospital encouragement of early SSC for both vaginal and cesarean births. Continued efforts to support evidence-based maternity practices are needed.

Trends in rooming-in practices among hospitals in the United States, 2007-2015.

BACKGROUND: Rooming-in, or keeping mothers and infants together throughout the birth hospitalization, increases breastfeeding initiation and duration, and is one of the Ten Steps to Successful Breastfeeding. METHODS: The Centers for Disease Control and Prevention's (CDC) Maternity Practices in Infant Nutrition and Care (mPINC) survey is a biennial census of all birth facilities in the United States and its territories. Data from the 2007-2015 mPINC surveys were used to assess trends in the prevalence of hospitals with most (≥90%) infants rooming-in more than 23 hours per day (ideal practice). Hospital practices among breastfed infants not rooming-in at night and reasons why hospitals without ideal rooming-in practices removed healthy, full-term, breastfed infants from their mothers' rooms were also analyzed. RESULTS: The percentage of hospitals with ideal practice increased from 27.8% in 2007 to 51.4% in 2015. Most breastfed infants who were not rooming-in were brought to their mothers at night for feedings (91.8% in 2015). Among hospitals without ideal rooming-in practices, the percentage removing 50% or more of infants from their mothers' rooms at any point during the hospitalization decreased for all reasons surveyed during 2007-2015; however, in 2015, hospitals still reported regularly removing infants for hearing tests (73.2%), heel sticks (65.5%), infant baths (40.2%), pediatric rounds (35.5%), and infant photos (25.4%). CONCLUSIONS: Hospital implementation of rooming-in increased 23.6 percentage points during 2007-2015. Continued efforts are needed to ensure that all mothers who choose to breastfeed receive optimal lactation support during the first days after giving birth.

Timing of Introduction of Complementary Foods to US Infants, National Health and Nutrition Examination Survey 2009-2014.

BACKGROUND: Although there has been inconsistency in recommendations regarding the optimal time for introducing complementary foods, most experts agree that introduction should not occur before 4 months. Despite recommendations, studies suggest that 20% to 40% of US infants are introduced to foods at younger than 4 months. Previous studies focused on the introduction of solid foods and are not nationally representative. OBJECTIVE: Our aims were to provide a nationally representative estimate of the timing of introduction of complementary foods and to describe predictors of early (<4 months) introduction. DESIGN: We conducted a cross-sectional analysis of 2009-2014 National Health and Nutrition Examination Survey data. PARTICIPANTS: The study included 1,482 children aged 6 to 36 months. MAIN OUTCOME MEASURES: Timing of first introduction to complementary foods (anything other than breast milk or formula) was analyzed. STATISTICAL ANALYSES PERFORMED: Prevalence estimates of first introduction to complementary foods are presented by month. Logistic regression was used to assess characteristics associated with early (<4 months) introduction. RESULTS: In this sample, 16.3% of US infants were introduced to complementary foods at <4 months, 38.3% between 4 and <6 months, 32.5% between 6 and <7 months, and 12.9% at ≥7 months of age. In unadjusted analyses, early introduction varied by breastfeeding status; race/Hispanic origin; Special Supplemental Nutrition Program for Women, Infants, and Children participation; and maternal age. In adjusted analyses, only breastfeeding status remained significant; infants who never breastfed or stopped at <4 months were more likely (odds ratio 2.27; 95% CI 1.62 to 3.18) to be introduced to complementary foods early than infants who breastfed ≥4 months. CONCLUSIONS: Despite using a broader definition of complementary foods, this analysis found a lower prevalence of early introduction in this nationally representative sample than previous studies that included only solids. However, many young children were still introduced to complementary foods earlier than recommended. Strategies to support caregivers to adhere to infant feeding guidelines may be needed.

Breastfeeding and Breast Cancer Risk Reduction: Implications for Black Mothers.

Breast cancer is the most commonly diagnosed cancer and a leading cause of death from cancer among U.S. women. Studies have suggested that breastfeeding reduces breast cancer risk among parous women, and there is mounting evidence that this association may differ by subtype such that breastfeeding may be more protective of some invasive breast cancer types. The purpose of this review is to discuss breast cancer disparities in the context of breastfeeding and the implications for black mothers. Black women in the U.S. have lower rates of breastfeeding and nearly twice the rates of triple-negative breast cancer (an aggressive subtype) compared with white women. In addition to individual challenges to breastfeeding, black women may also differentially face contextual barriers such as a lack of social and cultural acceptance in their communities, inadequate support from the healthcare community, and unsupportive work environments. More work is needed to improve the social factors and policies that influence breastfeeding rates at a population level. Such efforts should give special consideration to the needs of black mothers to adequately address disparities in breastfeeding among this group and possibly help reduce breast cancer risk. Interventions such as peer counseling, hospital policy changes, breastfeeding-specific clinic appointments, group prenatal education, and enhanced breastfeeding programs have been shown to be effective in communities of color. A comprehensive approach that integrates interventions across multiple levels and settings may be most successful in helping mothers reach their breastfeeding goals and reducing disparities in breastfeeding and potentially breast cancer incidence.

Age at Introduction to Solid Foods and Child Obesity at 6 Years.

BACKGROUND: Epidemiological evidence suggests that timing of introduction of solid foods may be associated with subsequent obesity, and the association may vary by whether an infant is breastfed or formula-fed. METHODS: We included 1181 infants who participated in the Infant Feeding Practices Study II (IFPS II) and the Year 6 Follow Up (Y6FU) study. Data from IFPS II were used to calculate the primary exposure and timing of solid food introduction (<4, 4-<6, and ≥6 months), and data from Y6FU were used to calculate the primary outcome and obesity at 6 years of age (BMI ≥95th percentile). We used multivariable logistic regression to assess the association between timing of the introduction of solids and obesity at 6 years and test whether this association was modified by breastfeeding duration (breastfed for 4 months vs. not). RESULTS: Prevalence of obesity in our sample was 12.0%. The odds of obesity was higher among infants introduced to solids <4 months compared to those introduced at 4-<6 months (odds ratio [OR] = 1.66; 95% CI, 1.15, 2.40) in unadjusted analysis; however, this relationship was no longer significant after adjustment for covariates (OR = 1.18; 95% CI, 0.79, 1.77). Introduction of solids ≥6 months was not associated with obesity. We found no interaction between breastfeeding duration and early solid food introduction and subsequent obesity. CONCLUSIONS: Timing of introduction of solid foods was not associated with child obesity at 6 years in this sample. Given the inconsistency in findings with other studies, further studies in larger populations may be needed.