1,721,401 research outputs found
Optimizing the Placement of Automated External Defibrillators in Marin County, CA — A Location-Allocation Analysis
No full textThesis (Master's)--University of Washington, 2025This study evaluated the spatial and temporal coverage of public automated external defibrillators (AEDs) in Marin County, California, from 2019 to 2024 to determine whether existing AEDs were optimally located to maximize Out-of-hospital cardiac arrest (OHCA) coverage and to identify additional placement opportunities. We defined coverage as the proportion of OHCAs occurring within 100 meters of an AED and differentiated between expected coverage (ignoring AED availability) and actual coverage (accounting for AED accessibility at the time of arrest). Using registry data on 321 publicly available AEDs and geocoded OHCA events, we found no significant difference between expected and actual coverage, suggesting temporal accessibility was not a major limiting factor. However, by incorporating 20 candidate AED sites identified through location-allocation modeling, OHCA coverage significantly improved by 2.93 percentage points (from 7.01% to 9.94%, p < 0.05), representing a 42% relative increase. This suggests that spatial distribution—not temporal availability—is the key for improved coverage in Marin County, and strategic placement of a limited number of additional AEDs could meaningfully enhance public access to defibrillation
Circulating levels of soluble Fas (sCD95) are associated with risk for development of a non-resolving acute kidney injury sub-phenotype
Full text linkThesis (Master's)--University of Washington, 2017-06ABSTRACT: Background Critically ill patients with acute kidney injury (AKI) can be divided into two sub-phenotypes, resolving or non-resolving, based on the trajectory of serum creatinine. It is unknown if the biology underlying these two AKI recovery patterns is different. Study Design Prospective longitudinal cohort study. Settings and Participants A cohort of 1240 patients with systemic inflammatory response syndrome and admitted to the intensive care unit at Harborview Medical Center, Seattle, Washington. Predictor Eight circulating biomarkers were measured using meso scale discovery technology. The biomarkers were representative of several biologic processes; apoptosis (soluble Fas), inflammation (soluble tumor necrosis factor receptor 1, interleukin 6, interleukin 8) and endothelial dysfunction, (angiopoietin 1, angiopoietin 2, and soluble vascular cell adhesion molecule 1). Outcome Acute kidney injury sub-phenotypes based on trajectory of serum creatinine. Results During the first 3 days of ICU admission, 802 (65%) subjects developed AKI; 492 (61%) had a resolving sub-phenotype and 310 (39%) had a non-resolving sub-phenotype. The non-resolving sub-phenotype was associated with higher mortality (adjusted RR 2.4 (95% CI 1.5, 3.9)), while the resolving sub-phenotype was not associated with an increased risk of death (adjusted RR 1.2 (95% CI 0.7, 2.1)). Soluble Fas was the only biomarker associated with a non-resolving sub-phenotype after adjustment for age, body mass index, diabetes and acute physiology and chronic health evaluation III scores (p < .001). Limitations Misclassification and secondary analysis. Conclusions Identifying modifiable targets in the Fas-mediated pathway may lead to strategies for prevention and treatment of a clinically important form of AKI
The Association of Enteral Protein Intake with Outcomes in Trauma ICU Patients
No full textThesis (Master's)--University of Washington, 2025Background: Critically ill trauma patients have distinct nutritional requirements due to increased catabolism and metabolic stress. Existing nutrition guidelines provide limited and outdated recommendations on optimal protein intake for this population. Recent studies suggest a potential dose-dependent harm associated with high protein intake in critically ill patients. We conducted a secondary analysis of a randomized clinical trial to investigate the relationship between early protein intake and ventilator-free days (VFDs), and to assess whether blood urea nitrogen (BUN)—a known marker of poor outcomes in ICU patients—mediates this relationship. Methods: This analysis included 329 trauma patients from a single-center randomized trial conducted between 2016 and 2021 at a Level 1 trauma center. The primary exposure was mean protein intake (g/kg/day) over the first week of ICU admission. The primary clinical outcome was VFDs, defined as days alive and free from mechanical ventilation within the first 28 days. Competing risks regression was used to analyze VFDs to calculate the subdistribution hazard of extubation, accounting for death as a competing event. A causal mediation analysis evaluated whether BUN mediated the relationship between protein intake and VFDs. The association between protein intake and secondary outcomes including acute respiratory distress syndrome (ARDS), ventilator-associated pneumonia (VAP), and aspiration were analyzed using logistic regression. Sensitivity analyses were performed for a subgroup of patients receiving ≥8kcal/kg/day. Results: Median patient age was 46 years (IQR: 30–59), 78% were male, and median injury severity score (ISS) was 34 (IQR: 26–43). Median protein intake was 1.6 g/kg/day (IQR: 1.0–2.0). Median VFDs was 14 (IQR 0–20). Each 1 g/kg/day of protein intake in the first week of ICU stay was associated with a significantly lower hazard of extubation (SHR 0.66; 95% CI: 0.53 to 0.81; p<0.001). Secondary outcomes, including ARDS, VAP, and aspiration, showed no significant associations with protein intake. Causal mediation analysis indicated that each additional 1 g/kg/day protein intake resulted in 3.53 fewer VFDs (95% CI: –4.81 to –2.30; p<0.001), with approximately 26% (95% CI: 12.0% to 41.0%) mediated by elevated BUN levels. Conclusions: In critically ill trauma patients, higher enteral protein intake early in ICU admission was associated with a lower hazard of extubation and fewer VFDs, partly due to elevations in BUN. These findings challenge current recommendations advocating high protein supplementation in trauma patients and highlight the need for further trials to define optimal protein dosing strategies tailored specifically to this high-risk population
Incident atrial fibrillation in relation to disability-free survival, risk of fracture, and changes in physical function in the Cardiovascular Health Study
No full textThesis (Ph.D.)--University of Washington, 2013Background: Atrial fibrillation (AF) is common in older adults and associated with an increased risk of stroke, heart failure, dementia, and death, but important gaps remain in our understanding of the physical and functional consequences of AF. The aim of this study was to investigate the associations of incident AF with disability-free survival, risk of fracture, and changes in gait speed and grip strength in the Cardiovascular Health Study (CHS), a population-based longitudinal cohort study of adults aged 65 years and older. Methods: The study population included up to 4462 CHS participants enrolled in fee-for-service Medicare, followed between 1991 and 2009. Individuals with prevalent AF or a history of stroke or heart failure at baseline were excluded. Incident AF during cohort follow-up was identified by annual study electrocardiogram (ECG), hospital discharge diagnosis, or AF diagnosis in Medicare inpatient, outpatient, or physician service claims. Disability-free survival was defined as survival free of Activities of Daily Living (ADL) disability. ADLs were self-reported at annual clinic visits or via telephone interview. Fracture (defined as fractures of the hip, distal forearm, pelvis, or humerus) was identified by hospital discharge diagnosis or Medicare claims. Gait speed (time to walk 15 feet, converted to meters per second) and grip strength (in kilograms) were assessed at annual clinic visits. We used Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals for the associations of incident AF with disability-free survival and the risk of fracture. Linear mixed effects models were used to examine incident AF and one-year change in grip strength and gait speed. All estimates were adjusted for baseline age sex, race, clinic, education, body mass index, smoking, baseline self-reported physical activity, and time-varying hypertension, use of anti-hypertensive medications, coronary heart disease, and diabetes. Estimates for the associations of incident AF with disability-free survival were further adjusted for interim stroke and heart failure. Results: Incident AF was associated with decreased disability-free survival (HR for death or ADL disability=1.71, 95% CI 1.55, 1.90, HR for ADL disability=1.36, 95% CI 1.18, 1.58) compared to individuals without incident AF, and this association persisted after adjustment for stroke and heart failure (HR for death or ADL disability=1.50, 95% CI 1.34, 1.66, HR for ADL disability=1.24, 95% CI 1.07, 1.44). Incident AF was not associated with changes in gait speed (estimated one-year change in subjects without AF = -0.011 m/s; with incident AF = -0.013 m/s; difference = -0.002 m/s, 95% CI -0.006, 0.003) or grip strength (estimated one-year change in subjects without AF = -0.47 kg; with incident AF = -0.48 kg; difference = -0.01 kg, 95% CI -0.13, 0.10). Individuals with incident AF were not at higher risk of fracture (adjusted HR=0.97, 95% CI 0.77, 1.21) or hip fracture (adjusted HR=1.09, 95% CI 0.83, 1.42). Conclusion: The results of this study suggest that incident AF is a risk factor for disability in older adults. However, incident AF does not appear to be a risk factor for fracture and does not appear to accelerate declines in gait speed or grip strength. Additional research is needed to understand the potential mechanisms through which AF influences disability and to examine whether prevention or treatment of AF can reduce the burden of disability in the elderly
Long-Term Air Pollution in Relation to Cardiac Structure, Function, and Supraventricular Arrhythmias
No full textThesis (Ph.D.)--University of Washington, 2020Background: Air pollution is an important contributor to cardiovascular morbidity, including risk of heart failure. Acute exposure is associated with inflammation, elevation of blood pressure, and episodes of atrial fibrillation (AF). However, less is understood about how long-term exposures may influence measures of atrial and ventricular structure and function, including supraventricular arrhythmias. No large longitudinal analyses have investigated these associations. Methods: In the setting of the Multi-Ethnic Study of Atherosclerosis (MESA), we investigated associations of participant-specific, spatiotemporal model-estimated concentrations of fine particulate matter (PM2.5), oxides of nitrogen (NOX), and ozone (O3) with both cardiac magnetic resonance imaging-derived measures of left atrial (LA) and left ventricular (LV) structure and function, as well as with supraventricular arrhythmias identified from 14-day ambulatory electrocardiography (ECG) monitors worn by participants. Multivariable linear regression and generalized estimating equations were used, adjusting for potential confounders including MESA study site. Results: Among 2,250 participants at MESA Exam 5 (2010-2012), five-year average exposure to PM2.5, NOX, and O3 was not significantly associated with measures of left atrial structure and contractility. Among 1,324 MESA participants with ambulatory ECG monitoring at MESA Exam 6 (2016–2018), five-year average concentration of pollutants was not associated with supraventricular arrhythmias, though high two-week average concentration of PM2.5 was associated with increased rates of supraventricular tachycardia (23% higher per 5ug/m3, 95% CI: 4%-46%). Higher one-year average pollutant concentration prior to MESA Exam 1 (2000-2002) was associated with greater left-ventricular mass index (LVMI) for NOX (1.8% per 40 parts per billion [ppb] NOX, 95% CI: 0.3, 3.3) and PM2.5 (1.6% per 5ug/m3 higher PM2.5, 95% CI: 0.3, 2.9), and lower LVMI for O3 (-3.5% per 10ppb O3). Greater ten-year average NOX concentration between Exams 1 and 5 was associated with reduced LV contractility as measured by left-ventricular circumferential strain, though this association was only marginally significant. All analyses were sensitive to adjustment for MESA study site. Conclusions: Our study offers mixed evidence for an association of long-term concentrations of PM2.5, NOX, and O3 with cardiac structure and function. We did not find evidence of associations between pollutants and LA structure, and the association of PM2.5 with supraventricular tachycardia was minimal and confined to two-week pollutant concentrations. We identified significant associations between long-term pollutant concentrations and cross-sectional LVMI in the direction hypothesized for PM2.5 and NOX, and opposite that hypothesized for O3, though the strong inverse correlation between O3 and both PM2.5 and NOX may influence this finding. These findings suggest a role for NOX, PM2.5, and O3 in influencing cardiac structure in MESA. Additional work is needed to clarify that role and better understand the biological underpinnings of these associations
A survey of salt intake, blood pressure, and non-communicable disease risk factors in Viet Nam
No full textThesis (Ph.D.)--University of Washington, 2014While numerous epidemiological studies have reported evidence of an association between dietary salt intake and blood pressure, the majority of this evidence has come from developed countries; little is known about the influence of salt consumption in developing countries. Furthermore, in Viet Nam -- a country that has undergone a rapid economic and demographic transition in the past 10-20 years -- nation-wide statistics are scarce, and previous studies attempting to characterize non-communicable disease risk factors were limited by small sample sizes or a limited number of investigated risk factors. Using data from 14,706 participants in a 2009 Viet Nam national survey, this dissertation validates the use of mid-morning spot urine collections as a practical alternative to 24-hour urine collections for estimating salt intake, assesses the association of salt consumption with untreated blood pressure among Vietnamese adults, and presents contemporary, nationally representative prevalence statistics for non-communicable disease (NCD) risk factors among adults in Viet Nam. In 154 participants who provided spot and 24-hour urine collections, we observed a moderate correlation (rho = 0.34 - 0.35) between spot urine estimated and 24-hour measured salt consumption. Correlations were higher in women (rho = 0.39 - 0.40) than in men (rho = 0.30 - 0.31). In adjusted regression models, we observed no evidence of an association of salt consumption with untreated systolic blood pressure or prevalent hypertension at a national scale in Viet Nam. The associations did not differ in subgroups defined by age, smoking, or alcohol consumption; however, the association of salt consumption with untreated systolic blood pressure was stronger in urban residents than in rural residents (p-value for interaction of urban/rural status with salt consumption, p = 0.02). After incorporating sampling and post-stratification weights, the prevalence of NCD risk factors among Vietnamese adults aged 25-65 in 2009 was higher among those living in urban areas than those living in rural areas. The levels of hypertension awareness, treatment, and control were below those seen in other low- and low-middle income countries. Given recent economic and demographic changes, public health interventions should address NCD risk factors that will become more prominent as the population ages
Associations between adverse childhood experiences and HIV risk behavior among adults in the United States toward the end of the COVID-19 Pandemic
No full textThesis (Master's)--University of Washington, 2024Background: Adverse Childhood Experiences (ACEs) have been linked to HIV risk behaviors in adulthood and have not been explored after the start of the COVID-19 pandemic. Purpose: This study investigates the contemporary relationship between ACEs and HIV risk behaviors. Methods: This study used cross-sectional data from the 2022 Behavioral Risk Factor Surveillance System and included a sample of 51,168 individuals (26,769 females and 24,399 males). Analyses included multivariable logistic regressions using a 13-item, 8-item, and individual ACE exposure variables, and a test for interaction between ACEs and race/ethnicity on HIV risk behavior in adulthood. Results: In adjusted analyses and compared with no reported ACEs, increasing number of reported ACEs was associated with progressively higher odds of HIV risk behaviors: 1 (OR = 1.76, 95% CI: 1.26, 2.47), 2 (OR = 1.76, 95% CI: 1.28, 2.41), 3 (OR = 2.22, 95% CI: 1.62, 3.04), and 4 or more (OR = 3.82, 95% CI: 2.94, 4.97). Conclusion: This study reveals a significant association between ACEs and HIV risk behavior, with a marked increase in risk among individuals reporting three or more ACEs, underscoring the cumulative impact of trauma
Patient-reported receipt of goal-concordant care among seriously ill outpatients - prevalence and associated factors
No full textThesis (Master's)--University of Washington, 2020Goal-concordant care is an important indicator of high-quality care in serious illness. We sought to estimate the prevalence of patient-reported receipt of goal-concordant care among seriously ill outpatients and identify factors associated with absence of patient-reported goal-concordance. We analyzed enrollment surveys from a multi-center cluster-randomized trial of outpatients with serious illness. Patients reported their prioritized healthcare goal and the focus of their current medical care; these items were matched to define receipt of goal-concordant care. We found that of 405 patients with a prioritized healthcare goal, 58% reported receipt of goal-concordant care, 17% goal-discordant care, and 25% were uncertain of the focus of their care. Patient-reported receipt of goal-concordance differed by patient goal. For patients who prioritized extending life, 86% reported goal-concordant care, 2% goal-discordant care, and 12% were uncertain of the focus of their care. For patients who prioritized relief of pain and discomfort, 51% reported goal-concordant care, 21% goal-discordant care, and 28% were uncertain of the focus of their care. Patients who prioritized a goal of relief of pain and discomfort were more likely to report goal-discordant care than patients who prioritized a goal of extending life (RRR 22.20; 95%CI 4.59, 107.38). This study found seriously ill outpatients who prioritize a goal of relief of pain and discomfort are less likely to report receipt of goal-concordant care than patients who prioritize extending life. Future interventions designed to improve receipt of goal-concordant care should focus on identifying patients who prioritize relief of pain and discomfort and promoting care aligned with that goal
The agreement between emergency department and intensive care unit depth of sedation assessment
No full textThesis (Master's)--University of Washington, 2019RATIONALE: During mechanical ventilation, assessment and treatment of pain and agitation are important to ease patient discomfort, allow for ventilator synchrony, and decrease work of breathing. Despite this, it is uncommon for patients intubated in the emergency department(ED) to have level of sedation documented using a standardized scale. Studies focused on early depth of sedation frequently use first intensive care unit (ICU) sedation assessment as a proxy for ED depth of sedation; however, little evidence supports this practice. We sought to demonstrate the level of agreement between Richmond Agitation and Sedation Scale (RASS) measurements documented in the ED and the initial ICU RASS. METHODS We performed a secondary analysis of LOTUS-FRUIT, a prospective cohort study of patients with acute respiratory failure requiring intubation at PETAL network institutions. Patients who were intubated in the prehospital or emergency setting and had a documented ED RASS were included. The period of analysis was from time of intubation to ICU admission. Weighted Cohen’s Kappa was used to compare agreement between ED and initial ICU RASS. McNemar’s test was used to compare documentation of deep sedation (RASS -3 to -5) in the ED and ICU. RESULTS: Of the 784 patients who were intubated in the pre-hospital setting or ED, 180 had both an ED and initial ICU RASS documented. The most common indications for mechanical ventilation were respiratory failure (47.8%) and altered mental status (42.2%). The median time from intubation to ICU arrival was 4 hours (IQR 2.2-5.8). Most patients were admitted to a medical ICU (52.8%) followed by mixed (19.4%), surgical (14.4%), cardiac (8.9%) and neurological (4.4%) ICUs. Using a quadratic weighted kappa, ED and ICU RASS demonstrated substantial agreement (kappa=0.64). There was no statistically significant difference in the proportion with deep sedation between ED and ICU (p=0.51). CONCLUSIONS: ED and ICU RASS measurements demonstrate substantial agreement. Although RASS assessments occurred uncommonly in the ED overall, when RASS in the ED was documented, patients were equally likely to be categorized as deeply sedated in the ED and on admission to the ICU. In settings where depth of sedation is not routinely measured in the ED, first ICU depth of sedation may serve as an appropriate proxy
Representation of Minoritized People with Cystic Fibrosis in CF Therapeutics Development Network Clinical Studies
No full textThesis (Master's)--University of Washington, 2025Black and Hispanic people with CF (PwCF) experience a greater burden of worse health outcomes related to pulmonary disease compared to White, non-Hispanic PwCF. Prior evidence suggests that these communities are underrepresented in clinical research in CF. We used clinical study data from four recent modulator studies (CHEC-SC, PROMISE, PROSPECT, and GOAL) as well as CF Foundation Patient Registry data on persons seen at the same centers while these studies were enrolling. We selected potential registry controls who had not enrolled into studies but were otherwise eligible based on inclusion and exclusion criteria. We assessed rates of study enrollment separately for Black race and Hispanic ethnicity versus non-Hispanic White PwCF as a reference. We used propensity weighted Poisson regression models to account for potential confounders in the relationship between race and study participation. This study analyzed the enrollment characteristics of 3,594 persons in modulator studies and compared them with 14,888 eligible individuals based on CFF Patient Registry data. Enrollees were younger (median age 19 years) and more likely to have at least three baseline visits and live within 30 miles of the study site. Multivariable analysis revealed racial/ethnic disparities in enrollment. Black individuals were significantly less likely than non-Hispanic White individuals to enroll in CHEC-SC and PROMISE, with a 17% and 32% lower likelihood, respectively. Hispanic individuals had lower enrollment in PROMISE but higher enrollment in PROSPECT. The differences in enrollment rates were stronger at sites with fewer minority participants. These results suggest that Black and Hispanic PwCF are significantly less likely to be included in CF clinical research than White PwCF. Future research will include analysis of multiple CF clinical studies to evaluate if this relationship is upheld in studies with varying inclusion/ exclusion criteria and clinical sites
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