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Objectives: To compare outcomes of neonates born from women with Class III obesity with those whose mothers were of normal body weight. Methods: A retrospective cohort study of live-born singleton infants was undertaken. Maternal prepregnancy body mass index (BMI) defined matched normal and Class III obese cohorts. Multivariable regression models were used to determine adjusted relative odds ratios (aOR) and 95% confidence intervals (CI) for selected adverse neonatal outcomes. Results: Newborns exposed to maternal Class III obesity had greater risks of fetal overgrowth and low cord artery pH. Class III obesity was protective against small for gestational age and low birthweight. There was no difference in the risk of preterm delivery, meconium in the amniotic fluid or breastfeeding initiation. Conclusions: The new knowledge generated by this study provides further information on unique challenges faced by newborns of women with Class III obesity, suggesting more specialized care in the intrapartum and neonatal periods may be beneficial. [ABSTRACT FROM AUTHOR]

Background: Grade repetition is practiced worldwide and varies considerably across the globe. Globally, around 32.2 million students repeated a grade at the primary education level in 2010. Although a large body of research has documented grade repetition's academic and non-academic effects, the limited evidence on associations between grade repetition and school bullying is inconsistent and ambiguous. This study aimed to investigate the global association of grade repetition with bullying victimization in a large-scale school-based cross-sectional study. Methods and findings: We used the latest global data from the Program for International Student Assessment (PISA) 2018. PISA 2018 was conducted between March and August 2018 in 80 countries and economies among students aged 15–16 years attending secondary education. The students reported their experiences of repeating a grade at any time point before the survey and of being bullied in the past 12 months. The outcome measures were 6 types of bullying victimization. We accounted for the complex survey design and used multivariate logistic regression models to estimate the odds ratios (ORs) with 95% confidence intervals (CIs) of grade repetition with bullying victimization after adjusting for potential confounders (sex; age group; migrant status; school type; economic, social, and cultural status; and parental emotional support). This study included 465,146 students (234,218 girls and 230,928 boys) with complete data on grade repetition and bullying victimization in 74 countries and economies. The lifetime prevalence of grade repetition was 12.26%, and 30.32% of students experienced bullying at least a few times a month during the past 12 months. Grade repetition was statistically significantly associated with each type of bullying victimization. The OR (95% CI) of overall bullying victimization for grade repeaters compared with their promoted peers was 1.42 (95% CI 1.32–1.52, p < 0.001). The sex-specific analysis produced similar results in both boys and girls. Furthermore, girls who repeated a grade had higher risks of being made fun of, being threatened, having possessions taken away, and being pushed around than boys. The major limitation is that this study only included students attending schools and therefore may be subject to possible selection bias. In addition, the cross-sectional design hinders us from establishing causality between grade repetition and bullying victimization. Conclusions: In this study, we observed that, globally, both boys and girls who repeat a grade are at increased risk of being bullied compared with promoted peers, but girls may experience higher risks than boys of specific types of bullying associated with repeating a grade. These findings provide evidence for the association of grade repetition with bullying victimization. Sex differences in risk of experiencing some types of bullying suggest that tailored interventions for girls who repeat a grade may be warranted. In a cross-sectional study, Qiguo Lian and colleagues investigate associations between repeating a grade and experiencing bullying victimization among adolescents enrolled in schools in 74 countries and economies. Author summary: Why was this study done?: Preventing school violence is a specific target of the United Nations Sustainable Development Goals. Few empirical studies involving large samples have examined the association of grade repetition with bullying victimization. What did the researchers do and find?: We examined the association of grade repetition with bullying victimization among 465,146 15-year-old students in 74 countries and economies. The prevalence of grade repetition and bullying victimization varied widely across countries and economies. Grade repetition was associated with bullying victimization in both boys and girls. Girls who repeated a grade experienced higher risks than boys of being made fun of, being threatened, having possessions taken away, and being pushed around. What do these findings mean?: The experience of repeating a grade may suggest a need for bullying interventions among both boys and girls. Tailored interventions for girls who repeat a grade may be warranted. [ABSTRACT FROM AUTHOR]

To investigate the knowledge and beliefs regarding the use of intrauterine devices (IUDs) for nulliparous women among Chinese health care providers and assess the potential factors related to their misconceptions and conservative beliefs. A self-administered survey was conducted at 2 Chinese national academic conferences in 2015. The questionnaire data obtained from 103 health care providers were analyzed to examine the providers' knowledge regarding the safety and effectiveness of IUDs and the complications associated with IUD use, as well as their beliefs regarding the suitability of IUDs for nulliparous women. An ordinal logistic regression model was used to evaluate the potential factors related to their beliefs. Misconceptions about the complications associated with IUD use were common among our respondents, and they were least likely to know that IUDs do not increase the risk of developing pelvic inflammatory disease (26/97) or ectopic pregnancy (23/102) (22.5%-26.8%). Only approximately 10% of the providers believed that adolescents (9/94) or unmarried nulliparas (10/95) could be candidates for IUDs. In contrast, they were more likely (37/96, 38.5%) to consider married nulliparous women as appropriate candidates (P <.001). Misconceptions about the complications of IUD use were associated with more conservative beliefs regarding IUD use for nulliparous women (adjusted odds ratio, 1.34; 95% confidence interval, 1.00-1.79). The health care providers' insufficient knowledge regarding IUDs contributed to their outdated and conservative beliefs about the suitability of IUDs for nulliparous women. In addition, the difference in the providers' beliefs regarding IUD use for married and unmarried nulliparous women might reflect the stigma associated with premarital sex in Chinese traditional culture. [ABSTRACT FROM AUTHOR]

Hypertension (HT) is a common chronic disease that often causes target-organ damage and severe complications, contributing to cardiovascular morbidity and mortality worldwide. Accumulating evidence suggests that inflammation plays a prominent role in the initiation and progression of HT. Multiple inflammatory biomarkers have been proposed to predict HT. Several new hematological parameters can reflect the inflammatory response and platelet activation. The major advantage of hematological parameters over conventional inflammatory markers is that they are relatively inexpensive and easily obtained from routine blood tests. Numerous studies have investigated several hematological parameters for their utility as predictive biomarkers for the diagnosis and prognosis of HT. Among them, the neutrophil to lymphocyte ratio (NLR), monocyte to high density lipoprotein cholesterol ratio (MHR), red cell distribution width (RDW), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and systemic immune-inflammation index (SII) have recently received attention. We searched PubMed and Embase databases (up to September 18, 2022) to assess the relationships between hematological parameters and HT. This review discusses the diagnostic and prognostic value of these hematological parameters in HT, providing an important basis for early screening, risk stratification, and optimal management of hypertensive patients. [ABSTRACT FROM AUTHOR]

Background: Youth with disabilities have the same right to sexual and reproductive health (SRH) as their peers without disabilities. However, their needs and rights are often ignored. Little is known about the knowledge, needs and access barriers related to SRH information among youth with different types of disabilities in China. Methods: A cross-sectional survey was carried out among 473 unmarried youth aged 15–24 with visual, hearing, physical disabilities in both urban and rural areas in China. Results: Out of a maximum possible score of 100, respondent's median score ranged from 30 to 50 for knowledge related to sexual physiology, STIs/HIV/AIDS and contraception. For these three categories of knowledge, respondents with hearing and physical disabilities or from rural areas scored lower than their counterparts with visual disabilities or from urban areas. The multivariate analyses showed that the residential area and education level were strong correlates of knowledge among respondents with visual and hearing disabilities. Other significant correlates were age for respondents with visual impairment and physical impairment, and single child status in the family and father's education level for respondents with hearing impairment. Sources of and barriers and preferences in accessing SRH information differed by type of disabilities, residential areas and gender. In general, school teachers were the primary and most preferred sources of SRH knowledge, followed by the Internet, peers/friends and parents. Unaware of where to get accurate information and feeling embarrassed to seek information were the two most frequently mentioned barriers in accessing SRH information. Conclusion: Respondents had poor knowledge of SRH and limited access to SRH information, especially those from rural areas. Efforts should be made to promote school and family-based sexuality education tailored for youth with different types of disabilities. Plain language summary: Youth with disabilities have the same sexual and reproductive health (SRH) needs as their peers without disabilities and the equal right to attain the highest standard of SRH. However, their SRH needs and rights are often overlooked or neglected. Studies on SRH among unmarried youth with disabilities are very limited in China. This study used data collected from 473 unmarried youths with different types of disabilities from both urban and rural areas in China, to understand their SRH knowledge and its associated factors, as well as barriers and preferences in accessing sexuality-related information. This study demonstrated that unmarried youth with disabilities lacked knowledge of SRH, especially those with hearing or physical disabilities and those from rural areas. In general, residential area and education level were significant correlates of knowledge among respondents. Sources of and barriers and preferences in accessing SRH information varied across types of disabilities, residential areas and gender. In general, school teachers were the primary and most preferred sources of knowledge, followed by the Internet, peers and parents. Unaware of the available sources of accurate information and feeling embarrassed to seek information were the most frequently mentioned barriers in accessing SRH information. The findings of the study highlight the need to reduce the barriers to sexuality education for unmarried youth with different types of disabilities. Efforts should be made to promote school and family-based sexuality education tailored for youth with different types of disabilities and empower them to seek information proactively. [ABSTRACT FROM AUTHOR]

Background: Gender nonconformity (GNC) (i.e., gender expression that differs from gender role expectations for feminine or masculine appearance and behavior) is an under-researched area of adolescent sleep health. The COVID-19 lockdown offers an opportunity to understand how the effect of GNC on adolescent health outcomes changes between school closure and reopening.Methods: We conducted a cross-sectional study in Shanghai, China, in 2020. The sample size for analysis was 3,265. The age-specific insufficient sleep was estimated according to National Sleep Foundation's sleep duration recommendations. The self-perceived and self-rated GNC were measured by the two items "On the same scale that goes from 100% as a girl to 100% as a boy, where do you think others see you?" and "On a scale that goes from feeling 100% like a girl to feeling 100% like a boy, where do you see yourself?", and birth sex. In addition, we calculated sex-stratified adjusted odds ratios (AORs) of insufficient sleep for students with high and moderate GNC compared to students with low GNC. Finally, we measured the AORs with self-perceived and self-rated GNC during COVID-19 school closure and reopening.Results: Among 3,265 students in grade 6-12 in the analytic sample, 1,567(48.0%) were assigned female at birth (AFAB), 3,188 (97.6%) Han, and 1,921(58.8%) in grade 6-9. Among AFAB students, high self-perceived GNC was significantly associated with insufficient sleep (AOR,1.65; 95%CI,1.30-2.09) during school closure. Insufficient sleep was associated with high self-rated GNC (AOR,1.73; 95%CI,1.23-2.44) and moderate self-rated GNC (AOR,1.69; 95%CI,1.29-2.22) during school closure. After school reopening, neither self-perceived nor self-rated GNC was associated with insufficient sleep among AFAB students. Among assigned male at birth (AMAB) students, none of the two kinds of GNC was associated with insufficient sleep in the two periods during the COVID-19 pandemic.Conclusions: This study suggests GNC is only associated with insufficient sleep among AFAB students during school closure. Furthermore, the association is nonsignificant among AMAB students. These findings indicate that GNC-related stigma within the family could be a risk factor for insufficient sleep among AFAB adolescents. [ABSTRACT FROM AUTHOR]

Background: Grade repetition is practiced worldwide and varies considerably across the globe. Globally, around 32.2 million students repeated a grade at the primary education level in 2010. Although a large body of research has documented grade repetition's academic and non-academic effects, the limited evidence on associations between grade repetition and school bullying is inconsistent and ambiguous. This study aimed to investigate the global association of grade repetition with bullying victimization in a large-scale school-based cross-sectional study.Methods and Findings: We used the latest global data from the Program for International Student Assessment (PISA) 2018. PISA 2018 was conducted between March and August 2018 in 80 countries and economies among students aged 15-16 years attending secondary education. The students reported their experiences of repeating a grade at any time point before the survey and of being bullied in the past 12 months. The outcome measures were 6 types of bullying victimization. We accounted for the complex survey design and used multivariate logistic regression models to estimate the odds ratios (ORs) with 95% confidence intervals (CIs) of grade repetition with bullying victimization after adjusting for potential confounders (sex; age group; migrant status; school type; economic, social, and cultural status; and parental emotional support). This study included 465,146 students (234,218 girls and 230,928 boys) with complete data on grade repetition and bullying victimization in 74 countries and economies. The lifetime prevalence of grade repetition was 12.26%, and 30.32% of students experienced bullying at least a few times a month during the past 12 months. Grade repetition was statistically significantly associated with each type of bullying victimization. The OR (95% CI) of overall bullying victimization for grade repeaters compared with their promoted peers was 1.42 (95% CI 1.32-1.52, p < 0.001). The sex-specific analysis produced similar results in both boys and girls. Furthermore, girls who repeated a grade had higher risks of being made fun of, being threatened, having possessions taken away, and being pushed around than boys. The major limitation is that this study only included students attending schools and therefore may be subject to possible selection bias. In addition, the cross-sectional design hinders us from establishing causality between grade repetition and bullying victimization.Conclusions: In this study, we observed that, globally, both boys and girls who repeat a grade are at increased risk of being bullied compared with promoted peers, but girls may experience higher risks than boys of specific types of bullying associated with repeating a grade. These findings provide evidence for the association of grade repetition with bullying victimization. Sex differences in risk of experiencing some types of bullying suggest that tailored interventions for girls who repeat a grade may be warranted. [ABSTRACT FROM AUTHOR]

Background: Studies on very young adolescents' romantic and sexual experiences would help inform the context in which early sex arises. However, such studies are scant in China due to sparse data and cultural issues. Method: This study used the GEAS baseline data conducted among1776 adolescents in Shanghai. Multi-group latent class analysis was used to explore adolescents' romantic and sexual experiences patterns and subgroups. Multi-nominal logistic regression was performed to identify the factors distinguishing different subgroups subsequently. Results: There were gender differences in the lifetime prevalence for very young adolescents' romantic and sexual-related behaviors. The Multi-group latent class analysis indicated that the participants could be classified into three classes: general group, early romance group, and sex exploratory group. Multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both gender, ever had a romantic relationship, and had more autonomy in deciding where to go than the general group; while male respondents in the sex exploratory group were older, ever had a romantic relationship, believed that boys should be more sexually active and more proactive than girls, had more autonomy on deciding where to go, and perceived less school connection and neighborhood cohesion. Female respondents in the sex exploratory group were older and less empowered in decision-making than the general group. Conclusions: The result provides a picture of romantic and sexual behavior patterns among both gender of very young adolescents in China. Current sex education needs not only to be culturally appropriate but also to address the harm of gender inequality and stereotypes, as well as to provide accessible and supportive services to help young adolescents personalize their received information and strengthen their skills in communication, decision making, and critical thinking. Plain language summary: Studies on teenagers' romantic and sexual experiences would help to prevent early sex arises before it really takes place. However, such studies are limited, especially in China. The traditional culture thought that youth should not start romance before college. This study used the Global Early Adolescent Study Shanghai site baseline data collected among1776 teenagers to explore their romantic and sexual experiences patterns and identify the influencing factors. There were significant gender differences in teenagers' romantic and sexual-related behaviors. According to the multi-group latent class analysis, we classified the teenagers into three classes: the general group, the early romance group, and the sex exploratory group. The multi-nominal logistic regression showed youth in the early romance group were more likely to had friends of both boys and girls, ever had boyfriend/girlfriend and were freer to go out than the general group; while boys in the sex exploratorygroup were older, ever had a boyfriend/girlfriend, believed it was normal for boys to be sexually active than girls, had more freedom to go out, and had less perception of care from school adults and neighborhood. Girls in the sex exploratory group were older and less likely to make decisions on their own. Given the result we found, we call for health researchers and educators to conduct sex education programs promoting more equal gender norms and provide services to help young adolescents get right information and strengthen their skills in communication, decision making and critical thinking. [ABSTRACT FROM AUTHOR]

Background: The coronavirus disease 2019 (COVID-19) pandemic affected almost 1.6 billion students or more than 90% of learners globally. However, the effect of school closures during COVID-19 pandemic on adolescent sleep duration remains unclear.Methods: We undertook a cross-sectional electronic survey in six junior and senior high schools in Shanghai, China from late June to early July 2020. We evaluated the changes of sleep duration on weekdays by comparing sleep duration hours and insufficient sleep (< 9 h for children aged 6-13 years or < 8 h for teenagers aged 14-17 years) in COVID-19 school closures and after school reopening. We also investigated possible sex differences in the changes of sleep duration.Results: A total of 3265 students completed the survey, the mean age was 14.56 ± 1.99 years, 1567 (47.99%) were girls and 1344 (41.17%) were in grades 10-12. The overall sleep duration decreased from 8.88 h in school closures to 7.77 h after school reopening, and the change (difference: - 1.11 h; 95%CI: - 1.16, - 1.07; P < 0.001) was statistically significant. The prevalence of insufficient sleep increased sharply from 21.10 to 63.98%, and the change (ratio:3.03; 95%CI:2.84, 3.23; P < 0.001) was statistically significant. Besides, the changes were greater in girls than in boys.Conclusion: Results of this study revealed that sleep duration was longer and percentage of sufficient sleep was higher during COVID-19 school closures in adolescent students. [ABSTRACT FROM AUTHOR]

Background: Little is known on the co-occurrence and heterogeneity of child sexual abuse (CSA) or health risk behavior (HRB) prevalence nor the associations among the victims.Objectives: To detect the prevalence and subgroups of adolescents reporting CSAs or HRBs, and to examine the association between the subgroups.Methods: Participants were secondary school students in a national survey in China (N = 8746). Self-reported CSA and HRB experiences were collected through a computer assisted questionnaire. Prevalence and confidence intervals were calculated. Multigroup latent class analysis (LCA) was used to examine latent subgroups of CSA and HRB. Dual latent class regression analysis was used to examine the association between CSA and HRB classes.Results: A total of 8746 students participated in our study. The prevalence of having ever experienced any of the reported seven CSA items was 12.9%. The preferred LCA model consisted of a three-class CSA latent variable, i.e. "Low CSAs"(95.7% of the total respondents), "Verbal or exhibitionism CSAs"(3.3%), and "high multiple CSAs" (1.1%); and a three-class HRB latent variable, i.e. "Low HRBs"(70.5%), "externalizing HRBs" (20.7%), and "internalizing HRBs" (8.7%). Students in the "Verbal or exhibitionism CSAs" or "high multiple CSAs" classes had higher probabilities of being in "externalizing HRBs" or "internalizing HRBs" classes. The probabilities were higher in "high multiple CSAs" class(male externalizing OR 4.05, 95%CI 1.71-9.57; internalizing OR 11.77, 95%CI 4.76-29.13; female externalizing OR 4.97, 95%CI 1.99-12.44; internalizing OR 9.87, 95%CI 3.71-26.25) than those in "Verbal or exhibitionism CSA"(male externalizing OR 2.51, 95%CI 1.50-4.20; internalizing OR 3.08, 95%CI 1.48-6.40; female externalizing OR 2.53, 95%CI 1.63-3.95; internalizing OR 6.05, 95%CI 3.73-9.80).Conclusions: Prevalence of CSA items varies. Non-contact CSAs are the most common forms of child sexual abuse among Chinese school students. There are different latent class co-occurrence patterns of CSA items or HRB items among the respondents. CSA experiences are in association with HRB experiences and the associations between latent classes are dose-responded. Multi-victimization has more significantly negative effects. The results could help identify high-risk subgroups and promote more nuanced interventions addressing adverse experiences and risk behaviors among at-risk adolescents. [ABSTRACT FROM AUTHOR]

Adolescent alcohol use was a major social and public health concern given its negative impacts. Previous studies indicated gender role attitudes (GRA) were associated with alcohol use; however, few studies focused on early adolescents (10 to 14 years) and similar researches were not found in China. Objective: This study sought to explore the association between GRA and alcohol use among early adolescents. Methods: A cross-sectional study was conducted among students in grades six to eight across three public secondary schools in Shanghai, China. Data were collected by Computer-Assisted Self-Interview (CASI) questionnaire on mobile tablets. Alcohol use was measured by self-report, and six items with 5-point Likert-type options assessed the attitude toward traditional gender roles. The logistic regression model was adopted to examine the associations between GAR and alcohol use. Results: Totally 1,631 adolescents aged 10 to 14 years with 50.33% of boys included in this study. The mean score of GRA in drinkers was significantly higher than nondrinkers among boys (3.03 vs. 2.78, p < 0.001) but not girls (2.15 vs. 2.18, p = 0.499). After controlling the covariates of age, depression, peers' substance use, social cohesion, etc., we found that more traditional GRA was associated with a higher risk of alcohol use among boys (OR = 1.39, 95%CI: 1.11–1.75), whereas the association was not significant among girls (OR = 0.96, 95%CI: 0.74–1.24). Conclusions: Traditional GRA may increase the risk of alcohol use among early adolescent boys, suggesting that altering traditional GRA among this population group may help to prevent alcohol use. [ABSTRACT FROM AUTHOR]

In this paper, we consider the optimal cross-hedging and risk control problem of a competitive firm facing exchange risk exposure in a multi-period setting. We present the optimal positions of currency futures and options to maximize the exponential utility of the terminal wealth by dynamic programming approach. To evaluate the potential effectiveness of cross-hedging with currency futures and options, we compare terminal wealth, utility based on terminal wealth and variance of the wealth accumulation path in three cases: hedging with futures and options, net futures hedging and no hedging. An empirical study of two cross-exchange rates of USD/EUR and CNY/USD is performed. The results show that cross-exchange rate futures and options always offer the firm an improved ability to hedge against the foreign exchange rate risks. Relative to no hedging, cross-hedging with currency futures and options or net currency futures hedging achieves positive returns. As the risk aversion coefficient increases, the firm's profit of futures hedging increases, while the profit of options hedging decreases. We suggest the firm with smaller risk aversion coefficient choose options hedging, and the firm with higher risk aversion coefficient choose futures hedging. Furthermore, when using currency derivatives for hedging, the wealth volatility also decreases significantly. Thus, for the multinational firms, cross-currency hedging is an efficient risk management technique to reduce their foreign exchange risk exposure. [ABSTRACT FROM AUTHOR]

Background: Unintended pregnancy and induced abortion among young (unmarried or nulliparous) women have become serious social and health issues in China, which are thought to partly result from low use of long-acting reversible contraception, such as intrauterine devices (IUDs). Considering that providers may play an especially important role in increasing use of this particular method, we investigated Chinese health care providers' attitudes and practices regarding IUDs use for nulliparous women, and further examine the potential factors and reasons contributing to their attitudes and practices. Methods: We recruited health care providers at two Chinese national academic conferences and surveyed them about knowledge of IUDs, willingness to recommend IUDs to nulliparous women, and their related practices. Modified Poisson regression was used to examine the potential factors related to their attitudes and practices. Results: Approximately a half of respondents reported unwillingness to recommend IUDs to nulliparous women. Providers with more misperceptions about the safety and contraindications were more likely to be unwilling to recommend IUDs to nulliparous women. Moreover, 71.0% of respondents rarely or never recommended or provided IUDs to nulliparous women. Providers' unwillingness to recommend IUDs to nulliparous women was associated with their infrequent practices (aPR=1.43; 95% CI: 1.04, 1.96). In addition to concerns about the side effects or complications, traditional sexual concept against premarital sex was often cited as a reason by Chinese health providers for their negative attitudes towards IUDs use for nulliparous women, a large proportion of whom are unmarried. Conclusions: Our findings suggest that negative attitudes and infrequent practices regarding IUDs use for nulliparous women are common in Chinese health care providers. Moreover, misperceptions about IUDs, as well as traditional sexual concept, contribute to Chinese health care providers' negative attitudes towards IUDs use for nulliparous women, and may further reduce their provision. Educational interventions are needed to improve providers' accurate knowledge of IUDs and fill the gap between traditional sexual concept and young women's needs of contraceptive services. [ABSTRACT FROM AUTHOR]

We performed a systematic review and meta-analysis of heme oxygenase 1 gene (HO-1) promoter polymorphisms and susceptibility to coronary artery disease (CAD) based on eligible studies retrieved from electronic databases from 2002 to 2013. Eleven studies, involving 10,170 patients with CAD and 6,868 controls, were included. Overall, no significantly decreased risk of CAD was found in persons with the SS genotype of the HO-1 (GT)n repeat length polymorphism compared with those with the LL + SL genotype. However, decreased risks of CAD were observed in the Asian subgroup, the coronary-artery-narrowing ≥50% subgroup, the myocardial infarction subgroup, the age- and sex-matched subgroup, and the good-quality-reports subgroup. The primary heterogeneity in the studies came from age and sex matching and the extent of coronary stenosis. CAD risk was significantly decreased for persons with the AA genotype of the T(-413)A single-nucleotide polymorphism versus those with the TT genotype, but most of the studies showed that the allele distribution was inconsistent with Hardy-Weinberg equilibrium. In this meta-analysis, we found that the (GT)n SS genotype was associated with decreased risk of CAD after controlling for biases due to age and sex matching, extent of coronary stenosis, ethnicity, and study quality. The relationship between the T(-413)A single-nucleotide polymorphism and CAD should be interpreted more cautiously. [ABSTRACT FROM PUBLISHER]

Respondent-driven sampling (RDS) is a method for recruiting “hidden” populations through a network-based, chain and peer referral process. RDS recruits hidden populations more effectively than other sampling methods and promises to generate unbiased estimates of their characteristics. RDS’s faithful representation of hidden populations relies on the validity of core assumptions regarding the unobserved referral process. With empirical recruitment data from an RDS study of female sex workers (FSWs) in Shanghai, we assess the RDS assumption that participants recruit nonpreferentially from among their network alters. We also present a bootstrap method for constructing the confidence intervals around RDS estimates. This approach uniquely incorporates real-world features of the population under study (e.g., the sample’s observed branching structure). We then extend this approach to approximate the distribution of RDS estimates under various peer recruitment scenarios consistent with the data as a means to quantify the impact of recruitment bias and of rejection bias on the RDS estimates. We find that the hierarchical social organization of FSWs leads to recruitment biases by constraining RDS recruitment across social classes and introducing bias in the RDS estimates. [ABSTRACT FROM PUBLISHER]

Objective: To explore the relationship between overweight and obesity and breastfeeding behaviors, a cohort study was conducted among 22,131 women who delivered in Ontario hospitals between April 1 2008 and March 31 2010. Methods: Data regarding maternal characteristics, maternal body mass index (BMI), infant characteristics, and breastfeeding practices were obtained through the Better Outcomes Registry & Network birth records Database. Multivariate linear regression analysis was used to determine the rates of three outcome measures - intention to breastfeed, exclusive breastfeeding in hospital, and exclusive breastfeeding upon discharge from hospital - between non-obese, overweight and obese patients. Results: While overweight mothers have similar intentions to breastfeed compared to non-overweight mothers (OR 1.03 (0.87-1.21), obese mothers were less likely to intend to breastfeed (OR 0.84 (0.70-0.99). Overweight and obese mothers were less likely to exclusively breastfeed in hospital compared to non-overweight mothers (aOR 0.67 (0.60-0.75) and 0.67 (0.60-0.75), respectively), and overweight and obese mothers were less likely to exclusively breastfeed on discharge (aOR 0.68 (0.61-0.76) and 0.68 (0.61-0.76), respectively). Conclusions: This study highlights that while overweight and obese women may benefit more from exclusive breastfeeding compared to non-overweight women, they are less likely to exclusively breastfeed in the immediate post-partum period. [ABSTRACT FROM AUTHOR]