1,720,963 research outputs found
Neonatal and fetal growth charts to identify preterm infants less than 30 weeks gestation at risk of adverse outcomes
No full textBACKGROUND:It is unclear whether a neonatal or a fetal growthstandard is a better predictor of adverse in-hospital newborn infantoutcome
Morbidity and Mortality in Small for Gestational Age Infants at 22 to 29 Weeks’ Gestation
No full textTo identify the relative risks of mortality and morbidities for small for gestational age (SGA) infants in comparison with non-SGA infants born at 22 to 29 weeks’ gestation.METHODS: Data were collected (2006–2014) on 156587 infants from 852 US centers participating in the Vermont Oxford Network. We defined SGA as sex-specific birth weight <10th centile for gestational age (GA) in days. Binomial generalized additive models with a thin plate spline term on GA by SGA were used to calculate the adjusted relative risks and 95% confidence intervals for outcomes by GA
Anthropometric charts for infants born between 22 and 29 weeks’ gestation
No full textOBJECTIVES: Using a large, racially diverse US dataset, we aimed primarily to: (1) fit and validate sex-specific birth weight and head circumference for gestational age charts for infants born at 22 to 29 weeks’ gestation; and (2) fit race-specific birth weight and head circumference for gestational age charts.
METHODS: We used data collected between 2006 and 2014 on 183 243 singleton infants without congenital malformations with gestational age between 22 weeks, 0 days and 29 weeks, 6 days from 852 US members of the Vermont Oxford Network. For the sex-specific charts, the final sample size included 156 587 infants who survived hospital discharge. From these 156 587, we abstracted a subset of 47 005 infants to fit sex-specific charts separately for white, black, and Asian infants. For all charts, we applied quantile regression models to predict infants’ birth weight and head circumference percentiles from gestational age expressed in days.
RESULTS: We successfully validated the overall sex-specific charts. Over most of the gestational age range, black infants, either girls or boys, had the lowest predicted birth weight as compared with white and Asian infants for many percentiles.
CONCLUSIONS: We fitted and validated new sex-specific charts using a recent, large, and racially diverse dataset. Future steps include using these charts to examine associations of weight and head circumference at birth with mortality and morbidity
Sex differences in mortality and morbidity of infants born at less than 30 weeks' gestation
No full textMETHODS: Infants of gestational ages 22 to 29 weeks born between January 2006 and December 2016 at a Vermont Oxford Network center in the United States were studied. We examined mortality and morbidity rate differences and 95% confidence intervals by sex and birth year. We tested temporal differences in mortality and morbidity rates between boys and girls by means of a likelihood ratio test (LRT) on nested binomial regression models with log links. RESULTS: A total of 205 750 infants were studied; 97 048 (47.2%) infants were girls. The rate for mortality and chronic lung disease decreased over time faster for boys than for girls (LRT P < .001 for mortality; P = .006 for lung disease). Restricting to centers that remained throughout the entire study period did not change all the above but additionally revealed a significant year-sex interaction for respiratory distress syndrome, with a faster decline among boys (LRT P = .04). Morbidities, including patent ductus arteriosus, necrotizing enterocolitis, early-onset sepsis, late-onset sepsis, severe intraventricular hemorrhage, severe retinopathy of prematurity, and pneumothorax, revealed a constant rate difference between boys and girls over time. CONCLUSIONS: Compared with girls, male infants born at <30 weeks’ gestation experienced faster declines in mortality, respiratory distress syndrome, and chronic lung disease over an 11-year period. Future research should investigate which causes of death declined among boys and whether their improved survival has been accompanied by a change in their neurodevelopmental impairment rate
Regional and racial/ethnic differences in perinatal interventions among periviable gestations
No full textOBJECTIVE: To examine whether there are: 1) regional differences in three perinatal interventions that reflect active treatment among periviable gestations and 2) racial–ethnic differences in the receipt of these perinatal interventions after accounting for hospital region.
METHODS: We conducted a retrospective study on neonates born at 776 U.S. centers that participated in the Vermont Oxford Network (2006–2017) with a gestational age of 22–25 weeks. The primary outcome was postnatal life support. Secondary outcomes included maternal administration of antenatal corticosteroids and cesarean delivery. We examined rates and 99% CI of the three outcomes by region. We also calculated the adjusted relative risks (aRRs) and 99% CIs for the three outcomes by race and ethnicity within each region using modified Poisson regression models with robust variance estimation.
RESULTS: Major regional variation exists in the use of the three interventions at 22 and 23 weeks of gestation but not at 24 and 25 weeks. For example, at 22 weeks of gestation, rates of life support in the South (38.3%; 99% CI 36.3–40.2) and the Midwest (32.7%; 99% CI 30.4–35.0) were higher than in the Northeast (20.2%; 99% CI 17.6–22.8) and the West (22.2%; 99% CI 20.0–24.4). Particularly in the Northeast, black and Hispanic neonates born at 22 or 23 weeks of gestation had a higher provision of postnatal life support than white neonates (at 22 weeks: black: aRR 1.84 [99% CI 1.33–2.56], Hispanic: aRR 1.80 [1.23–2.64]; at 23 weeks: black: aRR 1.14 [99% CI 1.08–1.20], Hispanic: aRR 1.12 [1.05–1.19]). In the West, black and Hispanic neonates born at 23 weeks of gestation also had a higher provision of life support (black: aRR 1.11 [99% CI 1.03–1.19]; Hispanic: aRR 1.10 [1.04–1.16]).
CONCLUSION: Major regional variation exists in perinatal interventions when managing 22- and 23-week neonates. In the Northeast and the West regions, minority neonates born at 22 and 23 weeks of gestation had higher provision of postnatal life support
Racial and ethnic differences over time in outcomes of infants born at less than 30 weeks' gestation
No full textObjectives: To examine changes in care practices over time by race and ethnicity and whether the decrease in hospital mortality and severe morbidities has benefited infants of minority over infants of white mothers.
Methods: Infants 22 to 29 weeks' gestation born between January 2006 and December 2017 at a Vermont Oxford Network center in the United States were studied. We examined mortality and morbidity rate differences and 95% confidence intervals for African American and Hispanic versus white infants by birth year. We tested temporal differences in mortality and morbidity rates between white and African American or Hispanic infants using a likelihood ratio test on nested binomial regression models.
Results: Disparities for certain care practices such as antenatal corticosteroids and for some in-hospital outcomes have narrowed over time for minority infants. Compared with white infants, African American infants had a faster decline for mortality, hypothermia, necrotizing enterocolitis, and late-onset sepsis, whereas Hispanic infants had a faster decline for mortality, respiratory distress syndrome, and pneumothorax. Other morbidities showed a constant rate difference between African American and Hispanic versus white infants over time. Despite the improvements, outcomes including hypothermia, mortality, necrotizing enterocolitis, late-onset sepsis, and severe intraventricular hemorrhage remained elevated by the end of the study period, especially among African American infants.
Conclusions: Racial and ethnic disparities in vital care practices and certain outcomes have decreased. That the quality deficit among minority infants occurred for several care practice measures and potentially modifiable outcomes suggests a critical role for quality improvement initiatives tailored for minority-serving hospitals
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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