Women with evidence of ischemia and no obstructive coronary artery disease (INOCA) have an increased risk of major adverse cardiac events, including heart failure with preserved ejection fraction (HFpEF), we examined pathophysiological findings present in both INOCA and HFpEF and compared it to reference control to identify a potential links between INOCA and HFpEF compared to reference controls.In this study, 56 participants undergone adenosine stress cardiac magnetic resonance imaging (CMRI) in, including 35 women with suspected INOCA, 13 women with HFpEF, and 8 reference control women. Myocardial perfusion imaging was performed at rest and with vasodilator stress with intravenous adenosine. Myocardial perfusion reserve index was obtained and processed using semiquantitative measurement using CVI42 software (Circle Cardiovascular Imaging Inc). Statistical analysis was performed using linear regression models, Fisher's exact tests, ANOVA, or Kruskal-Wallis tests. Results showed that Age (P = 0.007), Body surface area (0.05) were highest in the HFpEF group. Left ventricular ejection fraction (P = 0.02) was lower among the INOCA and HFpEF groups compared to reference controls. In addition, A graded reduction was noticed in myocardial perfusion reserve index in HFpEF vs. INOCA vs. reference controls (1.5 ± 0.3, 1.8 ± 0.3, 1.9 ± 0.3, P = 0.02), but wasn’t statistically significant once adjusted to age. In conclusion, reduced myocardial perfusion reserve appears to be a common pathophysiologic feature in INOCA and HFpEF patients compared to reference control women.

Objective: Central line-associated bloodstream infections (CLABSIs) are associated with high morbidity and mortality, longer hospital stays, and increased healthcare costs. It was hypothesized that the adoption of a new anchoring device (SecurAcath) for peripherally inserted central catheters (PICCs) in May 2021 had contributed to a reduction in CLABSI incidence at University of California San Diego (UCSD) hospitals in La Jolla and Hillcrest. This study aimed to investigate if the overall decline in CLABSI incidence was associated with a decline in PICC CLABSI using SecurAcath. Methods: We conducted a retrospective cohort study involving 106 patients with CLABSI who had one or more central lines (CL) in place more than two calendar days before the onset of CLABSI from January 1st, 2020, to July 31st, 2022, at UCSD hospitals. Data was divided into intervention (exposed to SecurAcath) and pre-intervention (unexposed to SecurAcath) groups. The variables of interest were CLABSI event date, CL types, and CL insertion and removal dates and location. Standardized infection rate (SIR) and CLABSI incidence rate (per 1000 line-days) were calculated to compare the two groups. Results: The SIR was not significantly changed (Pre = 0.54 vs. Intervention = 0.46, P-value = 0.3827), and CLABSI rates (per 1000 line-days) by CL type did not find significant differences between the two groups. When all patients were examined irrespective of time, the CLABSI rate for single internal jugulars (IJs) was higher than other single CLs (1.7/1000 line-days, P-value = 0.0002). In contrast, the CLABSI rate for multiple CLs: PICC and port-a-cath (PORT) was lower than other multiple CLs (0.09/1000 line-days, P-value = 0.0264). Conclusion: This study did not find evidence of a decrease in CLABSI following the universal adoption of SecurAcath devices for PICCs at UCSD hospitals. However, we found that single high-risk CLs were associated with a higher CLABSI rate, while combined use of low-risk CLs was associated with lower CLABSI rate. Surveillance of bloodstream infections inclusive of all CL types is needed to identify impactful interventions and assess other benefits associated with SecurAcath.

Background: In the United States, suicide is the second leading cause of death for adolescents ages 10-19, and adolescent suicide rates have been rising since 2007. Suicide rates in adolescents are higher in areas of lower urbanicity, but urbanicity is not evenly distributed across the U.S. Regional suicide differences have been found across the country, but no study has examined regional differences and the interaction with urbanicity. Objective: To compare the change in crude rates of suicide between populations of 10-19-year-old adolescents in three different levels of urbanicity with stratification by national region. Methods: Suicide rates were queried from the CDC WONDER database from 2007-2018 for 10-19-year-olds and stratified by collapsed urbanicity level based on the 2013 NCHS Urban-Rural Scheme for Counties. Linear regression analysis tested the impact of the interaction of region and urbanicity over time on suicide rates and trends. Results: Overall, 26,933 adolescents committed suicide from 2007-2018. Suicide rates were highest in nonmetro areas, followed by medium/small metro and large metro areas respectively, and rates of rise were highest in nonmetro areas. Regional differences in suicide rates were found in each stratum of urbanicity, but trends in suicide rates did not significantly differ by region, though they did differ by urbanicity overall. Conclusion: A regional differences in suicide rates between metro levels and increasing suicide trends between metro areas suggests that more support is needed in nonmetro areas, especially in the West, to prevent further increase in suicide in adolescents.

Background: Bystander cardiopulmonary resuscitation (BCPR) improves the low survival rate in out-of-hospital cardiac arrest (OHCA). We aim to estimate the potential impact of the San Diego County “Revive & Survive” initiative, a community BCPR training program with the goal to train 1 million San Diegans in hands-only CPR.

Methods: We adapted a decision tree model simulating health outcomes among a population with OHCA eligible for BCPR. The model was parameterized with the San Diego County Cardiac Arrest Registry to Enhance Survival (CARES) database from 2020-2023, which receives input from participating large healthcare agencies. Based on a systematic review, we assume community BCPR training increases the proportion of OHCA patients who receive BCPR by 41% and the chances of survival if BCPR is received by 59%. We estimate 5-year impacts on BCPR, deaths, and quality-adjusted life years (QALYs).

Results: Analysis suggests 8,445 (95% CI 7883.7-9006.1) OHCA cases eligible for BCPR will be tracked in CARES from 2024 to 2029. The model forecasts the implementation of Revive & Survive will result in an absolute increase of 1,701 (95% CI 1508.0-1906.0) BCPR events, leading to 467 (95% CI 312.5-648.5) lives and 1,730 (95% CI 1156.0-2403.7) QALYs saved compared to current interventions over five years.

Conclusions: Our model predicts that implementation of Revive & Survive will result in substantial increases in the number of OHCA patients in our population receiving BCPR, leading to increased survival rates in a large population. Additional benefits not examined include impacts on other populations, such as those not captured in CARES and organ transplant recipients.

Asthma is the leading chronic disease among the pediatric population. Rady Children’s Hospital in San Diego established the Severe Asthma Clinic (SAC), a multidisciplinary clinic, with a goal is to reduce asthma healthcare utilization and improve the quality of life for patients with severe asthma. This study aims to 1) describe the SAC patients' demographics, 2) assess the frequency of ED visits, hospitalizations, and systemic steroid prescriptions post-SAC visit, and 3) investigate changes in Asthma Therapy Assessment Questionnaire (ATAQ) scores and pulmonary function test (PFT) results with each SAC visit.A retrospective analysis was performed on patients seen at the clinic from 2015 to 2020. Measures were compared using paired Wilcoxon Signed-Rank tests, and a linear mixed-effects model with a random intercept structure. Results were reported in median and quartile (Q1-Q3) format. A total of 153 patients were included with a median age of 9.85 (6.57- 13.80) at the first SAC visit. With an increase in time by one-month post-SAC, there was improved asthma control and improved lung function (see Figure 3.1). Multidisciplinary care at the SAC was associated with significant decrease in healthcare utilization (ED visits, hospitalizations) and improvement in asthma control for pediatric patients with severe asthma.

Background: Persons who inject drugs (PWID) are at increased risk for infectious diseases and overdose, and need access to primary care and substance use disorder (SUD) services. Yet, PWID historically have avoided and delayed seeking care, in part due to lacking insurance coverage for services they need and an availability of these services at local clinics. The Affordable Care Act (ACA) made insurance mandatory and included SUD services as an essential health benefit.Objectives: This dissertation research sought to examine the impact of the implementation of the ACA on the use of SUD treatment (Chapter 2) and primary care services (Chapter 3) among PWID in San Diego. It also sought to understand the changes in offering of SUD services at community and free primary care clinics after this health reform was implemented (Chapter 4). Methods: This dissertation is comprised of three papers assessing different aspects of health service use among PWID in San Diego County. Papers one and two (Chapters 2 and 3) used data from a longitudinal cohort study of 576 PWID in San Diego (STAHR 2 Study) to determine the impact of the ACA on the use of SUD treatment and the use of primary care services, respectively. Paper three (Chapter 3) used facility-level data on community and free primary care clinics in San Diego County from the California Office of Statewide Health Planning and Development to understand changes in offering of SUD services at these clinics after the ACA compared to before. Results: For paper one (Chapter 2), there was an increase (12%) in use of SUD treatment after the ACA compared to before, with a similar increase (10%) in insurance coverage. The ACA was associated with greater use of SUD treatment among PWID and the strength of this association was not impacted by insurance coverage. For paper two (Chapter 3), there was an increase (4%) in primary care use after the ACA compared to before, with a much larger increase (24%) in those who had insurance coverage. The ACA was associated with greater use of primary care services among PWID and the strength of the association was not entirely explained by an increase in insurance coverage. Paper three (Chapter 4) showed an decrease of 7% in the number of community and primary care clinics that offered SUD services after the ACA compared to before, but an increase in the proportion of patients covered by Medi-Cal and had contact with a substance abuse counselor. Conclusion: These findings suggest that the ACA may have been an effective health policy for increasing access and use of essential health services among PWID in San Diego, and for bolstering SUD services in community and free primary care clinics.

Case investigation and contact tracing (CICT) is a strategy for preventing transmission of infectious diseases, deployed during the COVID-19 pandemic, to identify individuals before becoming symptomatic and/or infectious so they could test and quarantine in order to break chains of transmission. Since May 11, 2020, the UC San Diego Return to Learn program conducted CICT for UCSD students, faculty, and staff. Data collected through contact tracing efforts provides an estimate for adherence to social distancing efforts. Our study aimed to identify the number of close contacts per case as well as factors associated with changes in the number of close contacts. Using available data, cases investigated between July 2020 and April 2021, we examined case characteristics and determined the number of close contacts reported by cases over time. Trends in the number of contacts per case over time were examined using linear regression. Of the 968 cases investigated during this period, 33.9% were White/Middle Eastern, 51.1% were female, and 63.2% were 18-29 years old. Cases were stratified based on university affiliation, in which 56.4% were students (including student employees) and 43.6% were employees of UC San Diego. Findings indicated that the number of close contacts per case had a statistically significant association with age group and student status. Analyses showed an increase in the mean number of close contacts per case over time. Furthermore, we observed that the number of contacts per case increased after stay-at-home orders ended in San Diego county (p<0.001), but did not decrease after business closures and mask mandates were implemented (p=0.76). These findings suggest that changes in time and mitigation protocols (i.e., quarantine) can impact social distancing adherence by proxy of close contacts, which provide insights for future outbreak mitigation efforts and policy planning.