The brother's penalty: Boy preference and girls' health in rural China.

This paper identifies the health penalty experienced by girls due to having a brother from endogenous sibling gender composition. We propose a girls-to-girls comparison strategy and rule out the confounding effect from the sibship size, birth interval, and birth order. Employing an instrumental variable approach and data from the Chinese Family Panel Studies, we find that girls with a brother are demonstrably shorter and report poorer health. This "brother's penalty" manifests even prenatally. Alternative explanations, such as birth order disadvantages, are carefully addressed and ruled out. The results hold even after excluding gender-neutral ethnic minorities. This observed penalty is likely attributed to unequal resource allocation within families and potential parental neglect. This penalty is amplified in families with lower income and maternal education, implying resource constraints contribute to gender discrimination. Our findings highlight the importance of addressing intrafamily gender bias for ensuring equal opportunities and health outcomes. Clinical trial registration: Not applicable.

Using a Geosocial Networking App to Investigate New HIV Infections and Related Risk Factors Among Student and Nonstudent Men Who Have Sex With Men in Chengdu, China: Open Cohort Study.

BACKGROUND: In China, condomless sex among men who have sex with men (MSM) is the primary route of HIV infection in young people. Chengdu is a hotspot for reported HIV cases among young people nationwide. Extensive use of geosocial networking (GSN) smartphone apps has dramatically changed the pattern of sexual behavior among young MSM (YMSM). However, data on HIV incidence and the risk behavior of YMSM using the GSN app are still obscure. OBJECTIVE: This study aims to analyze and understand the HIV incidence and its risk factors among YMSM using GSN apps in Chengdu, China. METHODS: An open cohort study was conducted among YMSM aged 18-24 years through a gay GSN smartphone app in Chengdu, China, from July 2018 to December 2020. Every participant completed a web-based questionnaire on sociodemographic characteristics, sexual behaviors, and other related statuses; made a reservation for a web-based HIV testing; and then voluntarily got tested at the designated testing site. At least one additional HIV test was taken via the app during the study period, and participants were evaluated at the end of the study or at the time of HIV seroconversion. By dividing the sum of the observed HIV seroconversions by the observed person-years, HIV incidence was calculated and compared between the student and nonstudent MSM. Univariate and multivariate (Cox proportional hazards regression) analyses were used to discuss the risk factors for new HIV infections. RESULTS: In the study cohort, 24 seroconversions occurred among 625 YMSM who took at least two HIV tests through the app during the study period, contributing to 505 observed person-years. The HIV incidence rate per 100 person-years was 4.75 (95% CI 2.89-6.61) among all MSM, 3.60 (95% CI 1.27-5.93) among student MSM, and 5.88 (95% CI 2.97-8.79) among nonstudent MSM. In addition, the HIV incidence per 100 person-years was 11.11 (95% CI 4.49-17.73) among those who had resided in the area for 6 months or less and 7.14 (95% CI 1.52-12.77) among those with senior high school or less education. Two or more sexual partners (adjusted hazards ratio [HR] 3.63, 95% CI 1.08-12.23) in the preceding 6 months was a risk factor for new HIV infections. Consistent condom use for anal sex (adjusted HR 0.38, 95% CI 0.16-0.88) and insertive anal sex only (adjusted HR 0.10, 95% CI 0.01-0.75) in the preceding 6 months were protective factors for new HIV infections. CONCLUSIONS: The rate of new HIV infections among YMSM who actively used GSN smartphone apps was high, especially among migrant nonstudent MSM. Targeted interventions on GSN smartphone apps should be implemented to provide demand-adapted prevention and services to reduce the threat of HIV.

Impact of immediate initiation of antiretroviral therapy among men who have sex with men infected with HIV in Chengdu, southwest China: trends analysis, 2008-2018.

BACKGROUND: Given the rampant HIV epidemic among men who have sex with men (MSM) in Chengdu, southwest China, Treat All policy, defined as immediate antiretroviral therapy (ART) initiation after HIV diagnosis, was implemented since 2014. Real-world research evaluating impacts of immediate ART on HIV epidemics is needed to optimize policy-making as national and international guidelines have been lowering ART eligibility threshold. The purpose of this study is to: assess temporal trends of the HIV epidemic and impacts of Treat All policy among MSM; and lay foundation for HIV-related policy evaluation using longitudinal routine data from health information systems. METHODS: Data used in this study were HIV sentinel seroprevalence, annual reported HIV cases and ART coverage rate among MSM in Chengdu from 2008 to 2018, derived from national HIV/AIDS information system. Temporal trends of the HIV epidemic were described using Joinpoint Regression Program. Interrupted time-series method was deployed to evaluate Treat All policy. RESULTS: HIV sentinel seroprevalence rose from 11.20% in 2008 to 17.67% in 2013 and Annual Percent Change (APC) was 8.25% (95% CI - 2.40%, 20.07%), then decreased to 5.17% in 2018 (APC = - 19.63%, 95% CI - 27.54%, - 10.86%). Newly reported HIV cases increased from 168 cases in 2008 to 1232 cases in 2015 (APC = 26.99%, 95% CI 21.32%, 32.93%), and reduced to 1014 cases in 2018 (APC = - 8.80%, 95% CI - 18.45%, 2.01%). ART coverage rate has been climbing from 11.11% in 2008 to 92.29% in 2018 and Average Annual Percent Change was 16.09% (95% CI 11.76%, 20.59%). Results of interrupted time-series models showed that compared to an annual increase of 0.87% during pre-policy period, there was a decline of 3.08% (95% CI - 0.0366%, - 0.0250%) per year of HIV sentinel seroprevalence since 2014; and compared to an annual increase of 116 cases before 2014, there was an annual drop of 158 newly reported HIV cases (95% CI - 194.87%, - 121.69%) during the post-policy period. CONCLUSIONS: Immediate ART after HIV diagnosis could potentially curb HIV transmission at population level among MSM, along with other strategies. Future assessment of HIV prevention and control policy can be carried out using routinely collected longitudinal data from health information systems.

Robust outcome weighted learning for optimal individualized treatment rules.

Personalized medicine has received increasing attentions among scientific communities in recent years. Because patients often have heterogenous responses to treatments, discovering individualized treatment rules (ITR) is an important component of precision medicine. To that end, one needs to develop a proper decision rule using patient-specific characteristics to maximize the expected clinical outcome, i.e. the optimal ITR. Recently, outcome weighted learning (OWL) has been proposed to estimate optimal ITR under a weighted classification framework. Since most of commonly used loss functions are unbounded, the resulting ITR may suffer similar effects of outliers as the corresponding classifiers. In this paper, we propose robust OWL (ROWL) to build more stable ITRs using a new family of bounded and non-convex loss functions. Moreover, we extend the proposed ROWL method to the multiple treatment setting under the angle-based classification structure. Our theoretical results show that ROWL is Fisher consistent, and can provide the estimation of rewards' ratios for the resulting ITRs. We develop an efficient difference of convex functions algorithm (DCA) to solve the corresponding nonconvex optimization problem. Through analysis of simulated examples and a real medical dataset, we demonstrate that the proposed ROWL method yields more competitive performance in terms of the empirical value function and the misclassification error than several existing methods.

Member commitment in farmers' cooperatives in China: The role of contractual and relational governance mechanisms.

Farmers' cooperatives play a critical role in social, economic, and environmental sustainability in terms of poverty reduction, food quality and safety, farm sustainability, and members' well-being. However, they are generally faced with low or declining member commitment, which restricts their performance and sustainable development. This study aims to investigate the effect of cooperative governance on member commitment as well as the moderating effects of cooperative types through an empirical exploratory study applying a random sampling survey. The results indicate that both contractual and relational governance have significant positive effects on member commitment, but vary with cooperative types. Specifically, there is a greater effect of contractual governance in company-affiliated cooperatives than in primary cooperatives, while the effects of relational governance increase in the order of company-affiliated, primary, and company-led cooperatives. Moreover, relational governance displays a greater positive influence on member commitment than contractual governance. These findings suggest that cooperatives should take organizational features, contractual and relational governance into consideration to improve member commitment and sustainable development.

Molecular Transmission Network of Newly Reported HIV Infections in Pengzhou, Sichuan Province: A Study Based on Genomics and Spatial Epidemiology.

OBJECTIVE: The objective of this study was to understand the molecular transmission characteristics of newly reported HIV infections in the city of Pengzhou, Sichuan Province, to analyze the risk factors of transmission network and spatial clustering and the transmission characteristics, and to provide a scientific basis for precision prevention and intervention. METHODS: Anticoagulated whole blood was collected from newly reported HIV infections in Pengzhou from March 2019 to August 2021. After the plasma was isolated, the HIV-1 pol gene was amplified and sequenced by reverse transcriptase polymerase chain reaction (PCR). The obtained gene sequences were used to construct a maximum likelihood phylogenetic tree for the analysis of virus subtypes, and a molecular transmission network was constructed using the genetic distance method to evaluate the transmission pattern of people living with HIV/AIDS in Pengzhou. A logistic regression model was used to find out the potential risk factors for entering the molecular transmission network with the number of nodes ≥ 2. Spatial analysis is used to show the geographical pattern of the proportion of newly reported HIV infections entering the molecular transmission network, and a flow map is used to show the intensity of transmission within and between townships. RESULTS: A total of 463 newly reported HIV-infection sequences were obtained in this study, including 237 cases (51.19%) of CRF01_ AE, 159 cases (34.34%) of CRF07_BC, 45 cases (9.72%) of B, 15 cases (3.24%) of CRF08_BC and 7 cases (1.5%) of others. The number of clusters was the highest when the gene distance was 0.009, with a total of 246 sequences entering the network, forming 54 clusters, and the network entry rate was 55.36%. There were 170 sequences with more than two nodes in the network sequence. The logistic regression showed that compared with age < 50 years old, age ≥ 50 years old has a higher risk of transmission (OR = 3.43, 95% CI = 2.06-5.71); compared with farmers, the risk of transmission within industry is lower (OR = 0.046, 95% CI = 0.25-0.87); and compared with CRF07_BC, CRF01_AE (OR = 6.09, 95% CI = 3.60-10.30) and B (OR = 20.31, 95% CI = 8.94-46.13) had a higher risk of transmission. Men aged ≥ 50 years are mainly clustered with women between 50 and 70 years of age. In addition to being clustered with gay men, there are nine (50%) and three (16.7%) chains of transmission between gay men and heterosexual men and women, respectively. In the geographical space, there is no hot spot clustering of the molecular propagation network. The subtype B was mainly distributed in the town of Tianpeng and formed transmission networks in eastern Pengzhou;0020CRF01_AE is mainly distributed in the town of Lichun and formed transmission networks in the west and north of Pengzhou. CONCLUSION: This study reveals the characteristics and influencing factors of molecular network transmission in the region, as well as the spatial transmission characteristics of newly reported HIV infections in recent years, and reveals the geographical differences in HIV-1 transmission. The results provide a scientific basis for the development of local AIDS-specific intervention measures.

HIV/AIDS Knowledge, Depression, and HIV-Related Stigma Among Elderly Men in Rural China: A Hierarchical Regression Analysis.

This study explored the current status and influencing factors of HIV-related stigma among elderly men (≥50 years old) in rural Chengdu, China. A structured face-to-face interview survey was conducted among 286 elderly males from three towns in Chengdu using convenience sampling, 240 men (83.9%) who had heard of HIV/AIDS were included in the analysis. Hierarchical regression was used to examine the associated factors of HIV-related stigma, including demographic variables, HIV/AIDS knowledge level, receiving HIV/AIDS-related health education in the past year, depression, and anxiety, and to examine the moderating effect of educational level on HIV/AIDS knowledge and HIV-related stigma. Hierarchical regression analysis showed that men with lower HIV/AIDS knowledge scores, primary school or below educated, and depression had higher HIV-related stigma total score and social stigma dimensional scores than their counterparts. In addition, living alone was associated with higher HIV-related stigma, and elderly men with lower monthly income and those without HIV/AIDS-related health education in the past year had higher levels of social stigma. Higher HIV/AIDS knowledge score was significantly associated with lower HIV-related stigma level among those with middle school or above education level, but no such effect in those with primary school or below. In conclusion, the HIV-related stigma level among elderly men in rural Chengdu was high and positively associated with depression. HIV/AIDS education should target elderly men with low education, living alone, and low income, and interventions to promote mental health may work together to reduce HIV-related stigma in the rural elderly population.

HIV-Related Knowledge, Attitude, and Practices Research Among College Students - Six Chinese Cities, 2021.

What is already known about this topic?: The number of newly diagnosed human immunodeficiency virus (HIV) cases among Chinese youth 15-24 years of age shows an upward trend between 2010 and 2019. What is added by this report?: This survey is on a larger scale as compared to previous studies. It shows inadequate HIV knowledge - especially on HIV treatment, self-testing, and post-exposure prophylaxis - among college students. A significant gap exists between knowledge and behavior as indicated by the low condom use rate despite a high knowledge level. What are the implications for public health practice?: Findings suggest priorities for future HIV education and awareness creation of existing services. A low condom use rate at sexual debut suggests that HIV prevention education should start early.

Use of Geosocial Networking Apps and HIV Risk Behavior Among Men Who Have Sex With Men: Case-Crossover Study.

BACKGROUND: HIV disproportionately affects men who have sex with men (MSM) in China. The HIV epidemic is largely driven by unprotected anal sex (ie, sex not protected by condoms or HIV pre-exposure prophylaxis [PrEP]). The possible association between unprotected anal sex and the use of geospatial networking apps has been the subject of scientific debate. OBJECTIVE: This study assessed whether users of a gay geospatial networking app in China were more likely to use condoms when they met their partners online versus offline. A case-crossover analysis, with each person serving as his own control, was employed to address the potential bias that men looking for sex partners through an online dating medium might have inherently different (and riskier) patterns of sexual behavior than men who do not use online dating media. METHODS: A cross-sectional survey was administered in 2018 to adult male users of Blued-a gay geospatial networking app-in Beijing, Tianjin, Sichuan, and Yunnan, China. A case-crossover analysis was conducted among 1311 MSM not taking PrEP who reported engaging in both unprotected and protected anal sex in the previous 6 months. Multivariable conditional logistic regression was used to quantify the association between where the partnership was initiated (offline or online) and the act of unprotected anal sex, controlling for other interval-level covariates. Four sensitivity analyses were conducted to assess other potential sources of bias. RESULTS: We identified 1311 matched instances where a person reported having both an unprotected anal sex act and a protected anal sex act in the previous 6 months. Of the most recent unprotected anal sex acts, 22.3% (292/1311), were initiated offline. Of the most recent protected anal sex acts, 16.3% (214/1311), were initiated offline. In multivariable analyses, initiating a partnership offline was positively associated with unprotected anal sex (odds ratio 2.66, 95% CI 1.84 to 3.85, P<.001) compared with initiating a partnership online. These results were robust to each of the different sensitivity analyses we conducted. CONCLUSIONS: Among Blued users in 4 Chinese cities, men were less likely to have unprotected anal sex in partnerships that they initiated online compared with those that they initiated offline. The relationship was strong, with over 2.5 times the likelihood of engaging in unprotected anal sex in partnerships initiated offline compared with those initiated online. These findings suggest that geospatial networking apps are a proxy for, and not a cause of, high-risk behaviors for HIV infection; these platforms should be viewed as a useful venue to identify individuals at risk for HIV transmission to allow for targeted service provision.

User Preferences for an mHealth Approach to Support HIV Self-Testing and Linkage to HIV Prevention or Care Services for MSM in China.

This research qualitatively explored user preferences for an app-based mHealth approach to support HIV self-testing and linkage to HIV prevention or care services developed for men who have sex with men (MSM) in China. We conducted 12 online focus group discussions with MSM participants (N = 48) about their preferences for using an app to meet their HIV self-testing and service linkage needs. Data were examined using thematic analysis. Participants specified four domains to align program delivery with their preferences for app-based intervention: (1) expanding HIV prevention/antiretroviral therapy concepts beyond basic knowledge; (2) enhancing the style and presentation of app-based messages; (3) incorporating interactive and dynamic app-engagement features; and (4) creating a "one station" app that covers the continuum of HIV services. Given the changing landscapes of HIV knowledge and community/user preferences for app-based interaction, findings underscore how engagement with end-user participants is essential to optimize mHealth interventions for HIV.

Avian Influenza-Factors Affecting Consumers' Purchase Intentions toward Poultry Products.

Recently, continuing outbreaks of avian influenza in China have not only caused great loss to the agricultural sector but also brought fear and distrust to consumers, seriously undermining consumer confidence in chicken products. We investigated consumers' purchase intentions during avian influenza outbreaks by examining a regionally representative sample of 330 consumers in Guangzhou. With respect to 7 kinds of attributes, the ordered logit analysis indicated that possible health threat and uncertainty of the origin of poultry products may cause concern among consumers and cause them to avoid purchasing chicken products. Media reports have a great influence on consumers' intentions to purchase chicken products during avian influenza outbreaks. Overall, this study suggests establishing an effective mechanism of public knowledge (of chicken products' safety and quality) enhancement, in order to curb misleading media reports during avian influenza outbreaks.

Childhood obesity in China: Does grandparents' coresidence matter?

Childhood obesity in China has been increasingly cited as a major public health issue in recent decades. The effect of grandparents on grandchildren's weight outcome is under-analyzed. Using data from the China Health and Nutrition Survey, we examine the effect of grandparents' coresidence on childhood weight outcome with a sample of 2-13-year-old children in China. We use instrumental variables to address the potential endogeneity of grandparents' coresidence. We show that the effect of grandparents' coresidence on childhood weight outcome is significantly positive. Grandparents' coresidence affects a grandchild's weight outcome through changes in dietary patterns and physical activity. The effects on dietary patterns exist in urban areas and significantly lower in rural areas. Grandparents' coresidence decreases physical activity more in rural areas than in urban areas. Furthermore, the effects of coresidence on protein intake and physical activities of children above 6 are significantly higher for males than females. A robustness check, including an ordered logit model with a body mass index category and estimation with additional data, validates our findings.

Utility-based Weighted Multicategory Robust Support Vector Machines.

The Support Vector Machines (SVM) has been an important classification technique in both machine learning and statistics communities. The robust SVM is an improved version of the SVM so that the resulting classifier can be less sensitive to outliers. In many practical problems, it may be advantageous to use different weights for different types of misclassification. However, the existing RSVM treats different kinds of misclassification equally. In this paper, we propose the weighted RSVM, as an extension of the standard SVM. We show that surprisingly, the cost-based weights do not work well for weighted extensions of the RSVM. To solve this problem, we propose a novel utility-based weights for the weighted RSVM. Both theoretical and numerical studies are presented to investigate the performance of the proposed weighted multicategory RSVM.