Siyu Chen

Dr. Siyu Chen

JC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 June 2023 in JMIR Research Protocols
Verified
Journal Article
Open access
Siyu ChenSiyu Chen
Siyu Chen
QZQingpeng Zhang
Qingpeng Zhang
CCChee-Kit Chan
Chee-Kit Chan
FYFuk-yuen Yu
Fuk-yuen Yu
ACAndrew Chidgey
Andrew Chidgey
Zixin WangZixin Wang
Zixin Wang
Background: Counseling support for HIV self-testing (HIVST) users is essential to ensure support and linkage to care among men who have sex with men (MSM). An HIVST service with web-based real-time instruction, pretest, and posttest counseling provided by trained administrators (HIVST-OIC) was developed by previous projects. Although the HIVST-OIC was highly effective in increasing HIVST uptake and the proportion of HIVST users receiving counseling along with testing, it required intensive resources to implement and sustain. The service capacity of HIVST-OIC cannot meet the increasing demands of HIVST. Objective: This randomized controlled trial primarily aims to establish whether HIVST-chatbot, an innovative HIVST service with web-based real-time instruction and counseling provided by a fully automated chatbot, would produce effects that are similar to HIVST-OIC in increasing HIVST uptake and the proportion of HIVST users receiving counseling alongside testing among MSM within a 6-month follow-up period. Methods: A parallel-group, noninferiority randomized controlled trial will be conducted with Chinese-speaking MSM aged ≥18 years with access to live-chat applications. A total of 528 participants will be recruited through multiple sources, including outreach in gay venues, web-based advertisement, and peer referral. After completing the baseline telephone survey, participants will be randomized evenly into the intervention or control groups. Intervention group participants will watch a web-based video promoting HIVST-chatbot and receive a free HIVST kit. The chatbot will contact the participant to implement HIVST and provide standard-of-care, real-time pretest and posttest counseling and instructions on how to use the HIVST kit through WhatsApp. Control group participants will watch a web-based video promoting HIVST-OIC and receive a free HIVST kit in the same manner. Upon appointment, a trained testing administrator will implement HIVST and provide standard-of-care, real-time pretest and posttest counseling and instructions on how to use the HIVST kit through live-chat applications. All participants will complete a telephone follow-up survey 6 months after the baseline. The primary outcomes are HIVST uptake and the proportion of HIVST users receiving counseling support along with testing in the past 6 months, measured at month 6. Secondary outcomes include sexual risk behaviors and uptake of HIV testing other than HIVST during the follow-up period. Intention-to-treat analysis will be used. Results: Recruitment and enrollment of participants started in April 2023. Conclusions: This study will generate important research and policy implications regarding chatbot use in HIVST services. If HIVST-chatbot is proven noninferior to HIVST-OIC, it can be easily integrated into existing HIVST services in Hong Kong, given its relatively low resource requirements for implementation and maintenance. HIVST-chatbot can potentially overcome the barriers to using HIVST. Therefore, the coverage of HIV testing, the level of support, and the linkage to care for MSM HIVST users will be increased. Trial Registration: ClinicalTrial.gov NCT05796622; https://clinicaltrials.gov/ct2/show/NCT05796622 International Registered Report Identifier (IRRID): PRR1-10.2196/48447

13 August 2024 in BMC Medicine
Verified
Journal Article
Open access
PDF file
ZLZian Lin
Zian Lin
Siyu ChenSiyu Chen
Siyu Chen
LSLixian Su
Lixian Su
YLYuxue Liao
Yuxue Liao
HCHongbiao Chen
Hongbiao Chen
Zixin WangZixin Wang
Zixin Wang
Mothers play a crucial role in influencing their daughters’ HPV vaccination decisions. Addressing barriers to receiving HPV vaccination among mothers of girls may achieve two goals in one strike: increasing vaccination coverage among both mothers and their daughters. This study aims to examine the HPV vaccination uptake and its determinants among mothers of girls in China at both the individual and interpersonal levels. From July to October 2023, a cross-sectional online study was conducted to investigate HPV vaccine refusal for daughters aged 9–17 years among 11,678 mothers in Shenzhen, China. A randomized selection method was employed, targeting 11 primary schools and 13 secondary schools in Shenzhen. The research team invited mothers of girls to participate in an anonymous online survey. Multilevel logistic regression models (level 1: schools; level 2: individual participants) were employed to analyze the data. Among 11,678 mothers, 41.1% self-reported receiving at least one dose of HPV vaccination. Through multilevel logistic regression analysis, eight items measuring illness representations of HPV, which refers to how people think about HPV, were associated with higher HPV vaccination uptake (AOR: 1.02–1.14). These items included identity (identifying symptoms of HPV), timeline (whether HPV is acute/chronic), negative consequences, personal and treatment control (whether HPV is under volitional control), concern, negative emotions, and coherence (overall understanding of HPV). In addition, participants refusing HPV vaccines for the index daughters (AOR: 0.82, 95%CI: 0.76, 0.89) had lower vaccine uptake. Perceived more difficulties in accessing the 9-valent vaccines (AOR: 1.06, 95%CI: 1.04, 1.08) and more satisfaction with vaccine-related promotional materials (AOR: 1.50, 95%CI: 1.46, 1.54) at the individual level were associated with higher vaccine uptake. At the interpersonal factors, higher frequency of exposure to testimonials given by others about HPV vaccination on social media (AOR: 1.19, 95%CI: 1.14, 1.25) and thoughtful consideration of the veracity of the information (AOR: 1.11, 95%CI: 1.07, 1.16) were correlated with higher HPV vaccination uptake. These findings offer essential implications for modifying HPV disease perceptions, addressing difficulties in accessing the 9-valent HPV vaccines, and enhancing health communication needs to improve HPV vaccine uptake among mothers of girls.

17 June 2022 in Vaccines
Verified
Journal Article
Open access
PDF file
Zixin WangZixin Wang
Zixin Wang
YFYuan Fang
Yuan Fang
FYFuk-yuen Yu
Fuk-yuen Yu
Paul Shing-fong ChanPaul Shing-fong Chan
Paul Shing-fong Chan
Siyu ChenSiyu Chen
Siyu Chen
Fenghua SunFenghua Sun
Fenghua Sun
A COVID-19 vaccine booster dose is effective and safe for older adults. This study investigated facilitators and barriers to take up a COVID-19 vaccine booster dose among older adults in Hong Kong. Participants were Chinese-speaking community-dwelling adults aged ≥65 years. Telephone numbers were randomly selected from up-to-date telephone directories. A total of 395 participants completed the telephone interview. Logistic regression models were fitted. Among the participants, 31.6% received a COVID-19 vaccine booster dose. After adjustment for significant background characteristics, positive attitudes toward the booster dose, perceiving significant others would support them to receive the booster dose, and less uncertainty regarding the choice of the booster dose was associated with higher uptake of a COVID-19 vaccine booster dose. Concerns about poorer responses to the booster dose due to older age and the presence of chronic conditions were negatively associated with the dependent variable. In addition, the belief that governmental promotional materials could address their concern and were helpful for them to make decisions was associated with a higher COVID-19 vaccine booster dose uptake. Improving booster dose health promotion materials, modifying perceptions, involving significant others and reducing uncertainty are potentially useful strategies to improve COVID-19 vaccine booster dose uptake among older adults.

2 September 2022 in Vaccines
Verified
Journal Article
Open access
PDF file
Zixin WangZixin Wang
Zixin Wang
Siyu ChenSiyu Chen
Siyu Chen
YFYuan Fang
Yuan Fang
A significant decline in pediatric vaccination uptake due to the COVID-19 pandemic has been documented. Little is known about the parental willingness and associated factors of pediatric vaccination during the COVID-19 pandemic. An extensive literature search in the databases of PubMed, Scopus, Web of Science, and EBSCOhost were conducted. A total of 20 eligible studies published from 2020–2022 were included for systematic summary by a thematic analysis, among which 12 studies were included in a meta-analysis conducted with R-4.2.1. The prevalence of parental willingness to childhood/routine vaccination and seasonal influenza vaccination was 58.6% (95%CI 2.8–98.6%) and 47.3% (95%CI 25.3–70.5%). Moreover, there is no sufficient evidence of significant change in parental willingness to childhood/routine vaccination, human papillomavirus vaccination, or pneumococcal conjugate vaccination during the pandemic. However, a significant increase in parental willingness to vaccinate their children against seasonal influenza was found. In addition to the factors of parental vaccination willingness/hesitancy that are well-studied in literature, children/parents’ history of COVID-19 and children’s perceived vulnerability to COVID-19 were associated with parental willingness. Developing synergetic strategies to promote COVID-19 vaccination together with other pediatric vaccination is warranted during the pandemic. This may help to improve and/or catch up the vaccine uptake of children during and/or after the COVID-19 pandemic.

13 August 2023 in Vaccines
Verified
Journal Article
Open access
PDF file
Paul Shing-fong ChanPaul Shing-fong Chan
Paul Shing-fong Chan
YFYuan Fang
Yuan Fang
Joseph KawukiJoseph Kawuki
Joseph Kawuki
Siyu ChenSiyu Chen
Siyu Chen
XLXue Liang
Xue Liang
Zixin WangZixin Wang
Zixin Wang
This systematic review and meta-analysis summarises the literature on parental acceptance, parental hesitancy, uptake, and the associated factors of seasonal influenza vaccination (SIV) among children aged 6–59 months. Studies were sourced from the following platforms: PubMed, Web of Science, MEDLINE, and EMBASE databases. A random-effects model was used to evaluate the prevalence and 95% confidence intervals (CI) of parental acceptance, parental hesitancy, and SIV uptake in the last flu season and lifetime among children. A total of 36 studies were included for analysis. The overall prevalence was 64% for parental acceptance (95% CI: 51–75%), 34% for parental hesitancy (95% CI: 22–48%), 41% for SIV uptake in the last flu season (95% CI: 33–50%), and 46% for SIV uptake in a lifetime (95% CI: 20–74%). Associated factors of parental acceptance/hesitancy and uptake included the age of the children or parents, parental education level, household income level, ethnicity, and other modifiable factors, including perceived benefits, perceived barriers, perceived severity, perceived susceptibility, and cues to action related to SIV. Meta-regression analyses revealed regional differences in parental acceptance (Americas: 79% vs. Asia: 60%). The results provided implications informing us of the development of intervention programs targeting parents to improve SIV coverage among young children.

23 April 2023 in Vaccines
Verified
Journal Article
Open access
PDF file
Joseph KawukiJoseph Kawuki
Joseph Kawuki
Siyu ChenSiyu Chen
Siyu Chen
YFYuan Fang
Yuan Fang
XLXue Liang
Xue Liang
Paul Shing-fong ChanPaul Shing-fong Chan
Paul Shing-fong Chan
Zixin WangZixin Wang
Zixin Wang
This systematic review summarises the literature on Coronavirus Disease 2019 (COVID-19) vaccination, including acceptance, uptake, hesitancy, attitude and perceptions among slum and underserved communities. Relevant studies were searched from PubMed, Scopus, Web of Science and Google Scholar, following a pre-registered protocol in PROSPERO (CRD42022355101) and PRISMA guidelines. We extracted data, used random-effects models to combine the vaccine acceptance, hesitancy and uptake rates categorically, and performed meta-regression by R software (version 4.2.1). Twenty-four studies with 30,323 participants met the inclusion criteria. The overall prevalence was 58% (95% CI: 49–67%) for vaccine acceptance, 23% (95% CI: 13–39%) for uptake and 29% (95% CI: 18–43%) for hesitancy. Acceptance and uptake were positively associated with various sociodemographic factors, including older age, higher education level, male gender, ethnicity/race (e.g., Whites vs African Americans), more knowledge and a higher level of awareness of vaccines, but some studies reported inconsistent results. Safety and efficacy concerns, low-risk perception, long distance to vaccination centres and unfavourable vaccination schedules were prominent reasons for hesitancy. Moreover, varying levels of attitudes and perceptions regarding COVID-19 vaccination were reported with existing misconceptions and negative beliefs, and these were strong predictors of vaccination. Infodemic management and continuous vaccine education are needed to address existing misconceptions and negative beliefs, and this should target young, less-educated women and ethnic minorities. Considering mobile vaccination units to vaccinate people at home or workplaces would be a useful strategy in addressing access barriers and increasing vaccine uptake.