About

Yu-chin Chen is an Associate Professor in the Department of Economics at the University of Washington. She received her A.B. in Physics, M.P.P., M.A., and Ph.D. in Economics from Harvard University. Her research interests include International Finance, Open Economy Macroeconomics, and International Trade. She has contributed to the understanding of exchange rate predictability, commodity prices forecasting, growth and inequality in small open economies, and commodity currencies. Her work has been published in reputable journals such as the Review of Economics and Statistics, Quarterly Journal of Economics, Journal of Macroeconomics, and Journal of International Economics.

Research topics

• Internal medicine
• Medicine
• Environmental health
• Biology
• Intensive care medicine
• Pediatrics
• Cardiology
• Emergency medicine
• Demography
• Virology
• Microbiology

Selected publications

• Age-related patterns in self-harm and suicide methods among children and adolescents at a medical center in Taiwan

  Pediatrics & Neonatology · 2025-09-25

  letterOpen access1st authorCorresponding

  Suicide is a leading cause of mortality among youth in Taiwan, with a marked increase in suicidal behavior among children since 2019.1 Understanding suicide methods is crucial for developing intervention strategies. In Taiwan, individuals with suicide attempts are mandatorily reported through the National Suicide Surveillance System (NSSS).2 This study conducted a retrospective review of cases involving children reported via this system at a medical center in Taiwan in 2016–2023. Only the first recorded attempt was included; repeated attempts were excluded.

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• Optimal surveillance intervals for hepatocellular carcinoma screening in cirrhotic patients with hepatitis C infection: a Taiwanese national cohort study

  BMC Cancer · 2025-07-04

  articleOpen access

  BACKGROUND: Hepatocellular carcinoma (HCC) surveillance guidelines recommend ultrasound screening every 6 months, which was determined empirically. Since liver disease progression is heterogeneous among different etiologies, it is clinically valuable to analyze patients with specific etiologies. The aim of this study was to evaluate the impact of surveillance intervals, duration of cirrhosis, and HCC risk factors on the survival of hepatitis C virus (HCV) cirrhotic patients. METHODS: This nationwide cohort study included adult patients who were newly diagnosed as having HCV-related cirrhosis between January 2007 and December 2018. 5,093 newly diagnosed cirrhotic HCV related HCC patients were analyzed. The timing of ultrasonography screening was categorized into 4 cohorts: 0- to 6-month cohort (6-month cohort), 7- to 12-month cohort (12-month cohort), 13- to 24-month cohort (24-month cohort), and not screened within 2 years cohort (unscreened cohort). The chance of early stage of HCC diagnosis and receiving curative treatment were calculated. Association between surveillance interval and all-cause mortality was analyzed adjusting for lead-time bias. RESULTS: The 6-month group had the highest likelihood of being diagnosed with an early-stage HCC, followed by the 12-month group (OR = 0.69; 95% CI 0.55-0.85) and the 24-month group (OR = 0.355; 95% CI 0.27-0.47), the last by the unscreened group (OR = 0.296; 95% CI 0.22-0.40). The 6-month group had the highest likelihood of being received curative treatment, followed by the 12-month group (OR = 0.721, 95% CI 0.58-0.89) and the 24-month group (OR = 0.584; 95% CI 0.44-0.77), the last by the unscreened group (OR = 0.513; 95% CI 0.38-0.69). The 6-month group had the least likelihood of all-cause mortality, followed by the 12-month group (HR = 1.134; 95% CI 1.02-1.26), the 24-month group (HR = 1.570; 95% CI 1.39-1.77), and the unscreened group (HR = 1.520; 95% CI 1.33-1.73). After adjusting for lead-time bias, the 6-month group had the least likelihood of all-cause mortality. In the 6-month group, cirrhotic HCV patients with an AFP less than 20 ng/ml, with a MELD score less than 20, with cirrhosis duration between 3-5 years had better survival. CONCLUSION: A 6-month surveillance interval can significantly improve the detection rate of early-stage HCC, likelihood of receiving curative treatment, and prolong the overall survival of cirrhotic HCV patients.

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• Abstract No. 268 Correlation of Pre Locoregional Therapy Percutaneous Core Biopsy Histopathologic Grade in LI-RADS 5 Hepatocellular Carcinoma (HCC) with Post Orthotopic Liver Transplant HCC Recurrence and Survival

  Journal of Vascular and Interventional Radiology · 2025-02-19

  article
  PublisherDOI

• Adolescent and Young Adult Suicide and Self-harm: Exploring Changes in Risk Factors from 2016 to 2023

  Asian Journal of Social Health and Behavior · 2025-05-30 · 2 citations

  articleOpen access1st author

  Introduction: From 2014 to 2022, the suicide rate among adolescents and young adults in Taiwan doubled. Self-harm is recognized as a significant risk factor for suicide. This study aimed to examine changes in the predisposing factors for suicide and self-harm in this population over time. Methods: We included individuals under 25 years of age who were reported to the National Suicide Surveillance System for suicidal or self-harm behaviors at a medical center in Tainan from 2016 to 2023. We conducted a retrospective review of comprehensive patient histories and outcomes. Results: The study included 648 individuals under 25 years of age, with a median age of 20 years and 75.6% of female participants. The cohort included 270 individuals from the early period (2016–2019) and 378 from the late period (2020–2023). Logistic regression analysis revealed significant changes in factors between the two periods. Compared with the early period, the late period was associated with increased rates of depressive disorder (adjusted odds ratio [aOR]: 2.23, 95% confidence interval [CI]: 1.54–3.23) and bipolar disorder (aOR: 3.77, 95% CI: 1.81–7.85). Taking a leave of absence (aOR: 3.63, 95% CI: 2.28–5.78, P < 0.001), child abuse (aOR: 3.52, 95% CI: 1.79–6.94, P < 0.001), and domestic violence (aOR: 2.37, 95% CI: 1.11–5.08, P = 0.03) also significantly increased. In contrast, suicide at home (aOR: 0.55, 95% CI: 0.38–0.79, P = 0.001) decreased significantly. Conclusion: The social and psychological landscape of adolescents and young adults has shifted, requiring tailored strategies to address these evolving risks.

  PublisherDOI

• Emergence of multidrug-resistant E. coli ST8346 isolates carrying three distinct plasmids with NDM-5, KPC-2, and OXA-181

  Journal of Infection and Public Health · 2024-11-16 · 2 citations

  articleOpen access

  E. coli ST8346 is a unique strain associated with the potential carriage of multiple carbapenemases. Three unique E. coli ST8346 isolates were identified, each concurrently harboring multiple carbapenemases, including bla NDM-5 , bla KPC-2 , and/or bla OXA-181 . This study aimed to characterize the genetic and plasmid structures of these isolates to understand their transmission and resistance mechanisms. Antibiotic resistance profiles, genetic relatedness, and plasmid structures were determined using antibiotic susceptibility testing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), S1 nuclease PFGE, and long-read sequencing. All the strains were carbapenem resistant. PFGE revealed close genetic relationships among the isolates, despite the lack of geographical or epidemiological connections. bla NDM-5 , bla KPC-2 , and bla OXA-181 were located on separate plasmids. Plasmids harboring bla NDM-5 showed genetic similarities to bla NDM-5 -bearing IncF plasmids in the United Kingdom. The IncA/C plasmids harboring bla KPC-2 had identical sequences resembling a plasmid from a K. pneumoniae strain in Taiwan, except for the bla KPC-2 region, which matched a strain from China, indicating a hybrid plasmid. This study is the first to identify and characterize the coexistence of bla NDM-5 , bla KPC-2 , and bla OXA-181 in E. coli ST8346 isolates. The spread appears to be due to independent acquisition events. We identified the putative origins of these plasmids and detected a possible recombination event in a novel IncA/C plasmid. These findings emphasize the importance of ongoing surveillance and further investigations.

  PublisherDOI

• 0433 Suppression of the Default Mode Network Affects the Arousal and Reduces Time in Non-Restorative Sleep

  SLEEP · 2024-04-20

  articleOpen access

  Abstract Introduction We recently demonstrated that continuous theta burst stimulation (cTBS), a form of suppressive transcranial magnetic stimulation (TMS), was effective at improving total sleep time, sleep efficiency and arousal index scores in people with symptoms of insomnia (Killgore, 2023, zsad077.0332). We now present additional analyses on the effects of this stimulation on functional brain activation during a complex cognitive task (multi-source interference task; MSIT) that targets the cingulo-frontal-parietal cognitive/attention network and its correlations with overnight polysomnography (PSG). Methods Nineteen people (11 females) with moderately severe symptoms of insomnia (age=27.2 SD=6.6), underwent active or sham cTBS followed by an overnight PSG monitored sleep study on two counterbalanced occasions separated by at least a week. Immediately before and after each cTBS/sham stimulation, participants completed functional MRI scans that included the MSIT. Contrasts were created between the more difficult interference condition and the simple control condition and task activation changes were compared across time and treatment condition using paired t-tests, repeated measures ANOVA, and within-condition Pearson’s correlations. Results A paired t-test of the primary task contrast (interference>control) maps showed a significant decline from pre- to post-treatment in a region of the supplementary motor area (SMA) for the active cTBS (p< 0.001, FWE corrected), but no change for the sham condition, as evidenced by a significant time x treatment interaction (p=.004). Moreover, for the sham condition, activation of this region was correlated with more time in wake/non-restorative sleep (i.e., wake, N1, N2, awakenings, and arousal index, all p-values<.05), while for the active cTBS, changes in activation within this region were no longer associated with indices of poor sleep. Conclusion Building on our previously reported finding that cTBS reduced arousal and improved sleep time, this analysis suggests that activity within the SMA may play a role in mediating the insomnia-related symptoms with respect to arousal. Under sham conditions, increased activity of the SMA was associated with increased awakenings and arousal index. This disruptive effect appears to be eliminated by cTBS to the DMN. This result raises the possibility that insomnia symptoms may be partially mediated through the interactions between DMN and cognitive-attention networks. Support (if any) USAMRAA: W81XWH2010173

  PublisherOA PDFDOI

• 0435 Continuous Theta-burst Stimulation Lowers the Impact of Anxiety on Sleep Duration in Individuals with Insomnia

  SLEEP · 2024-04-20

  articleOpen access

  Abstract Introduction Repetitive Transcranial Magnetic Stimulation (rTMS) is a procedure by which a magnetic coil is used to stimulate specific regions of the brain to bring about alterations in function. Continuous theta-burst stimulation (cTBS) is a form of rTMS that was used to suppress cortical excitability and lower within network connectivity in the Default Mode Network (DMN). Connectivity within the DMN is associated with rumination and mind-wandering. Prior research indicates that pre-sleep anxiety is associated with increased sleep latency and decreased sleep continuity. As part of a larger project, we hypothesized that pre-sleep anxiety would negatively impact total sleep time, as measured by polysomnography (PSG), but that this effect would be reduced or eliminated in the active cTBS condition compared to sham. Methods We administered cTBS to 20 participants with insomnia symptoms (Nmales = 8, Mage=31.6, SD=6.7) (Nfemales =12, Mage=23.8, SD=4.3). Participants then underwent one administration of sham stimulation and one administration of active cTBS to the left angular gyrus node of the DMN in a randomized order separated by one week. The State Trait Anxiety Inventory (STAI-S) was administered immediately before each session, and PSG data was collected during overnight laboratory stays following the TMS sessions. We ran two linear regressions between STAI-S scores and total sleep time - one analysis for the sham condition and another for the active condition. Results Elevated STAI-S scores (M=41.6, SD=6.984) predicted decreased total sleep time (Mean minutes=393.75, SD=48.45) for the sham cTBS condition (F(1,18)=8.689, p=.009; β=-.571, p=.009). In contrast, the relationship between STAI-S scores (M=40.9, SD=50.35) and total sleep time (Mean minutes=403.8, SD=5.34) was not significant for the active cTBS condition (F(1,18)=2.409, p=.138; β=-.344, p=.138). Conclusion Prior data presented from this trial revealed that active cTBS improved TST overall. However, here we further demonstrated that higher pre-sleep anxiety predicted a lower sleep duration for the sham cTBS condition but not for the active cTBS condition, suggesting that the active cTBS may mitigate the effects of anxiety on sleep. These findings support the applicability of continuous theta-burst stimulation in treating psychiatric conditions related to sleep difficulties, such as anxiety. Support (if any) US Army Medical Research Acquisition Activity Grant: W81XWH2010173

  PublisherOA PDFDOI

• 0432 Neuromodulation of REM Sleep: Age-Associated Effects of Transcranial Magnetic Stimulation

  SLEEP · 2024-04-20

  article

  Abstract Introduction We recently reported findings from a project that used a form of repetitive transcranial magnetic stimulation (rTMS) known as continuous theta burst stimulation (cTBS) to modulate connectivity within the brain’s Default Mode Network (DMN) as a potential treatment for insomnia. Continuous theta-burst stimulation(cTBS) was used to reduce cortical excitability within the DMN. Our prior analyses showed that the approach significantly improved total sleep time, sleep efficiency, N3 latency, and the arousal index, but rapid eye-movement (REM) did not appear affected. Based on growing evidence that REM sleep may show changes in the third decade and beyond, and that the effects of rTMS may be, at least partially, influenced by age, we further explored the potential effect of age in this dataset. Methods cTBS was administered to a total of 20 participants with self-reported insomnia symptoms (Mage=26.90, SD=6.56). Each participant underwent one round of sham stimulation and one round of active cTBS in a randomized order with one week in between. Participants were monitored with polysomnography (PSG) during a 7-hour sleep window. We first examined the association between age and REM sleep at each visit. A repeated measures ANOVA was employed, incorporating age as a covariate to assess potential age-dependent effects on cTBS effects. Results REM duration was positively correlated with age for the active cTBS visits (r=0.506, p=0.023) but not for the sham (r=-0.059, p= .806). With age as a covariate, the ANOVA revealed a significant effect of TMS treatment on REM sleep duration, F(1,18)=7.507, p=0.013. Participants in the TMS treatment group experienced an increase in REM sleep duration compared to the sham group when age was controlled in the analysis. Conclusion Age significantly influenced the effect of cTBS on REM sleep outcomes. The finding that older individuals demonstrated a greater effect of stimulation on REM duration suggests potential implications for clinical application in individuals with insomnia. Future work may focus on refining therapeutic strategies for sleep modulation, advocating for a personalized and age-aware approach. Support (if any) US Army Medical Research Acquisition Activity Grant: W81XWH2010173

  PublisherDOI

• Sex-Based Disparities in Acute Myocardial Infarction Treatment Patterns and Outcomes in Older Adults Hospitalized Across 6 High-Income Countries: An Analysis From the International Health Systems Research Collaborative

  Circulation Cardiovascular Quality and Outcomes · 2024-02-08 · 11 citations

  articleOpen access

  BACKGROUND: Sex differences in acute myocardial infarction treatment and outcomes are well documented, but it is unclear whether differences are consistent across countries. The objective of this study was to investigate the epidemiology, use of interventional procedures, and outcomes for older females and males hospitalized with ST-segment-elevation myocardial infarction (STEMI) and non-ST-segment-elevation myocardial infarction (NSTEMI) in 6 diverse countries. METHODS: We conducted a serial cross-sectional cohort study of 1 508 205 adults aged ≥66 years hospitalized with STEMI and NSTEMI between 2011 and 2018 in the United States, Canada, England, the Netherlands, Taiwan, and Israel using administrative data. We compared females and males within each country with respect to age-standardized hospitalization rates, rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery within 90 days of hospitalization, and 30-day age- and comorbidity-adjusted mortality. RESULTS: Hospitalization rates for STEMI and NSTEMI decreased between 2011 and 2018 in all countries, although the hospitalization rate ratio (rate in males/rate in females) increased in virtually all countries (eg, US STEMI ratio, 1.58:1 in 2011 and 1.73:1 in 2018; Israel NSTEMI ratio, 1.71:1 in 2011 and 2.11:1 in 2018). Rates of cardiac catheterization, percutaneous coronary intervention, and coronary artery bypass graft surgery were lower for females than males for STEMI in all countries and years (eg, US cardiac catheterization in 2018, 88.6% for females versus 91.5% for males; Israel percutaneous coronary intervention in 2018, 76.7% for females versus 84.8% for males) with similar findings for NSTEMI. Adjusted mortality for STEMI in 2018 was higher for females than males in 5 countries (the United States, Canada, the Netherlands, Israel, and Taiwan) but lower for females than males in 5 countries for NSTEMI. CONCLUSIONS: We observed a larger decline in acute myocardial infarction hospitalizations for females than males between 2011 and 2018. Females were less likely to receive cardiac interventions and had higher mortality after STEMI. Sex disparities seem to transcend borders, raising questions about the underlying causes and remedies.

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• Transcranial Magnetic Stimulation of the Default Mode Network to Improve Sleep in Individuals With Insomnia Symptoms: Protocol for a Double-Blind Randomized Controlled Trial

  JMIR Research Protocols · 2024-01-26 · 5 citations

  articleOpen access

  BACKGROUND: Cortical hyperarousal and ruminative thinking are common aspects of insomnia that have been linked with greater connectivity in the default mode network (DMN). Therefore, disrupting network activity within the DMN may reduce cortical and cognitive hyperarousal and facilitate better sleep. OBJECTIVE: This trial aims to establish a novel, noninvasive method for treating insomnia through disruption of the DMN with repetitive transcranial magnetic stimulation, specifically with continuous theta burst stimulation (cTBS). This double-blind, pilot randomized controlled trial will assess the efficacy of repetitive transcranial magnetic stimulation as a novel, nonpharmacological approach to improve sleep through disruption of the DMN prior to sleep onset for individuals with insomnia. Primary outcome measures will include assessing changes in DMN functional connectivity before and after stimulation. METHODS: A total of 20 participants between the ages of 18 to 50 years with reported sleep disturbances will be recruited as a part of the study. Participants will then conduct an in-person screening and follow-on enrollment visit. Eligible participants then conduct at-home actigraphic collection until their first in-residence overnight study visit. In a double-blind, counterbalanced, crossover study design, participants will receive a 40-second stimulation to the left inferior parietal lobule of the DMN during 2 separate overnight in-residence visits. Participants are randomized to the order in which they receive the active stimulation and sham stimulation. Study participants will undergo a prestimulation functional magnetic resonance imaging scan and a poststimulation functional magnetic resonance imaging scan prior to sleep for each overnight study visit. Sleep outcomes will be measured using clinical polysomnography. After their first in-residence study visit, participants conduct another at-home actigraphic collection before returning for their second in-residence overnight study visit. RESULTS: Our study was funded in September 2020 by the Department of Defense (W81XWH2010173). We completed the enrollment of our target study population in the October 2022 and are currently working on neuroimaging processing and analysis. We aim to publish the results of our study by 2024. Primary neuroimaging outcome measures will be tested using independent components analysis, seed-to-voxel analyses, and region of interest to region of interest analyses. A repeated measures analysis of covariance (ANCOVA) will be used to assess the effects of active and sham stimulation on sleep variables. Additionally, we will correlate changes in functional connectivity to polysomnography-graded sleep. CONCLUSIONS: The presently proposed cTBS protocol is aimed at establishing the initial research outcomes of the effects of a single burst of cTBS on disrupting the network connectivity of the DMN to improve sleep. If effective, future work could determine the most effective stimulation sites and administration schedules to optimize this potential intervention for sleep problems. TRIAL REGISTRATION: ClinicalTrials.gov NCT04953559; https://clinicaltrials.gov/ct2/show/NCT04953559. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/51212.

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Frequent coauthors

• Kenneth Rogoff

  56 shared

• Barbara Rossi

  35 shared

• Dennis T. Ko

  University of Toronto

  19 shared

• Ying‐hui Chou

  University of Arizona

  15 shared

• Natalie S. Dailey

  13 shared

• William D. S. Killgore

  University of Arizona

  12 shared

• Samantha Jankowski

  New York State Psychiatric Institute

  12 shared

• Nicole Huang

  National Yang Ming Chiao Tung University

  12 shared

Education

• B.A., Physics

  Harvard University

• Other

  Harvard University

• M.A.

  Harvard University

• Ph.D., Economics

  Harvard University