Parental Factors Associated with COVID-19 Vaccine Uptake for Children over 5 Years of Age in Texas

The COVID-19 vaccine is safe and effective for children, yet parental hesitancy towards vaccinating children against the virus persists. We conducted a telephone-administered weighted survey in Texas to examine parents' sociodemographic factors and medical conditions associated with COVID-19 vaccination intention for parents with unvaccinated children ages 5-17 years. We collected responses from 19,502 participants, of which 4879 were parents of children ages 5-17 years. We conducted multiple logistic regression with Lasso-selected variables to identify factors associated with children's vaccination status and parents' intention to vaccinate their children. From the unweighted sample, less than half of the parents (46.8%) had at least one unvaccinated child. These parents were more likely to be White, English-speaking, not concerned about illness, privately insured, and unvaccinated for COVID-19 themselves (p < 0.001). In the adjusted regression model, parents who were unvaccinated (vs. having COVID-19 booster, aOR = 28.6) and financially insecure (aOR = 1.46) had higher odds of having unvaccinated children. Parents who were Asian (aOR = 0.50), Black (aOR = 0.69), Spanish-speaking (aOR = 0.57), concerned about illness (aOR = 0.63), had heart disease (aOR = 0.41), and diabetes (aOR = 0.61) had lower odds of having unvaccinated children. Parents who were Asian, Black, Hispanic, Spanish-speaking, concerned about illness for others, and vaccine-boosted were more likely to have vaccination intention for their children (p < 0.001). Children's vaccination is essential to reduce COVID-19 transmission. It is important to raise awareness about the value of pediatric COVID-19 vaccination while considering parents' sociodemographic and medical circumstances.

Lifetime Traumatic Brain Injury and Risk of Post-Concussive Symptoms in the Millennium Cohort Study

Traumatic brain injury (TBI) is prevalent among active duty military service members, with studies reporting up to 23% experiencing at least one TBI, with 10-60% of service members reporting at least one subsequent repeat TBI. A TBI has been associated with an increased risk of cumulative effects and long-term neurobehavioral symptoms, impacting operational readiness in the short-term and overall health in the long term. The association between multiple TBI and post-concussive symptoms (PCS), however, defined as symptoms that follow a concussion or TBI, in the military has not been adequately examined. Previous studies in military populations are limited by methodological issues including small sample sizes, the use of non-probability sampling, or failure to include the total number of TBI. To overcome these limitations, we examined the association between the total lifetime number of TBI and total number of PCS among U.S. active duty military service members who participated in the Millennium Cohort Study. A secondary data analysis was conducted using the Millennium Cohort Study's 2014 survey (n = 28,263) responses on self-reported TBI and PCS (e.g., fatigue, restlessness, sleep disturbances, poor concentration, or memory loss). Zero-inflated negative binomial models calculated prevalence ratios (PRs) and 95% confidence intervals (CIs) for the unadjusted and adjusted associations between lifetime TBIs and PCS. A third of military participants reported experiencing one or more TBIs during their lifetime with 72% reporting at least one PCS. As the mean number of PCS increased, mean lifetime TBIs increased. The mean number of PCS by those with four or more TBI (4.63) was more than twice that of those with no lifetime TBI (2.28). One, two, three, and four or more TBI had 1.10 (95% CI: 1.06-1.15), 1.19 (95% CI: 1.14-1.25), 1.23 (95% CI: 1.17-1.30), and 1.30 times (95% CI: 1.24-1.37) higher prevalence of PCS, respectively. The prevalence of PCS was 2.4 (95% CI: 2.32-2.48) times higher in those with post-traumatic stress disorder than their counterparts. Active duty military service members with a history of TBI are more likely to have PCS than those with no history of TBI. These results suggest an elevated prevalence of PCS as the number of TBI increased. This highlights the need for robust, longitudinal studies that can establish a temporal relationship between repetitive TBI and incidence of PCS. These findings have practical relevance for designing both workplace safety prevention measures and treatment options regarding the effect on and from TBI among military personnel.

Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of a Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

OBJECTIVE

This study was undertaken to examine averted stroke in optimized stroke systems.

METHODS

This secondary analysis of a multicenter trial from 2014 to 2020 compared patients treated by mobile stroke unit (MSU) versus standard management. The analytical cohort consisted of participants with suspected stroke treated with intravenous thrombolysis. The main outcome was a tissue-defined averted stroke, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis and no acute infarction/hemorrhage on imaging. An additional outcome was stroke with early symptom resolution, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours attributed to thrombolysis.

RESULTS

Among 1,009 patients with a median last known well to thrombolysis time of 87 minutes, 159 (16%) had tissue-defined averted stroke and 276 (27%) had stroke with early symptom resolution. Compared with standard management, MSU care was associated with more tissue-defined averted stroke (18% vs 11%, adjusted odds ratio [aOR] = 1.82, 95% confidence interval [CI] = 1.13-2.98) and stroke with early symptom resolution (31% vs 21%, aOR = 1.74, 95% CI = 1.12-2.61). The relationships between thrombolysis treatment time and averted/early recovered stroke appeared nonlinear. Most models indicated increased odds for stroke with early symptom resolution but not tissue-defined averted stroke with earlier treatment. Additionally, younger age, female gender, hyperlipidemia, lower National Institutes of Health Stroke Scale, lower blood pressure, and no large vessel occlusion were associated with both tissue-defined averted stroke and stroke with early symptom resolution.

INTERPRETATION

In optimized stroke systems, 1 in 4 patients treated with thrombolysis recovered within 24 hours and 1 in 6 had no demonstrable brain injury on imaging. ANN NEUROL 2024;95:347-361.

Mortality and Morbidity Among Individuals With Hypertension Receiving a Diuretic, ACE Inhibitor, or Calcium Channel Blocker: A Secondary Analysis of a Randomized Clinical Trial

Importance

The long-term relative risk of antihypertensive treatments with regard to mortality and morbidity is not well understood.

Objective

To determine the long-term posttrial risk of primary and secondary outcomes among trial participants who were randomized to either a thiazide-type diuretic, calcium channel blocker (CCB), or angiotensin-converting enzyme (ACE) inhibitor with up to 23 years of follow-up.

Design, Setting, and Participants

This prespecified secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a multicenter randomized, double-blind, active-controlled clinical trial, followed up with participants aged 55 years or older with a diagnosis of hypertension and at least 1 other coronary heart disease risk factor for up to 23 years, from February 23, 1994, to December 31, 2017. Trial participants were linked with administrative databases for posttrial mortality (N = 32 804) and morbidity outcomes (n = 22 754). Statistical analysis was performed from January 2022 to October 2023.

Interventions

Participants were randomly assigned to receive a thiazide-type diuretic (n = 15 002), a CCB (n = 8898), or an ACE inhibitor (n = 8904) for planned in-trial follow-up of approximately 4 to 8 years and posttrial passive follow-up for up to 23 years.

Main Outcomes and Measures

The primary end point was mortality due to cardiovascular disease (CVD). Secondary outcomes included all-cause mortality, combined fatal and nonfatal (morbidity) CVD, and both mortality and morbidity for coronary heart disease, stroke, heart failure, end-stage renal disease, and cancer.

Results

A total of 32 804 participants (mean [SD] age, 66.9 [7.7] years; 17 411 men [53.1%]; and 11 772 Black participants [35.9%]) were followed up for all-cause mortality and a subgroup of 22 754 participants (mean [SD] age, 68.7 [7.2] years; 12 772 women [56.1%]; and 8199 Black participants [36.0%]) were followed up for fatal or nonfatal CVD through 2017 (mean [SD] follow-up, 13.7 [6.7] years; maximum follow-up, 23.9 years). Cardiovascular disease mortality rates per 100 persons were 23.7, 21.6, and 23.8 in the diuretic, CCB, and ACE inhibitor groups, respectively, at 23 years after randomization (adjusted hazard ratio [AHR], 0.97 [95% CI, 0.89-1.05] for CCB vs diuretic; AHR, 1.06 [95% CI, 0.97-1.15] for ACE inhibitor vs diuretic). The long-term risks of most secondary outcomes were similar among the 3 groups. Compared with the diuretic group, the ACE inhibitor group had a 19% increased risk of stroke mortality (AHR, 1.19 [95% CI, 1.03-1.37]) and an 11% increased risk of combined fatal and nonfatal hospitalized stroke (AHR, 1.11 [95% CI, 1.03-1.20]).

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial in an adult population with hypertension and coronary heart disease risk factors, CVD mortality was similar between all 3 groups. ACE inhibitors increased the risk of stroke outcomes by 11% compared with diuretics, and this effect persisted well beyond the trial period.

Trial Registration

ClinicalTrials.gov Identifier: NCT00000542.

Outcomes of patients with pre-existing disability managed by mobile stroke units: A sub-analysis of the BEST-MSU study

BACKGROUND

Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients.

AIM

To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients.

METHODS

Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared.

RESULTS

Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS.

CONCLUSION

PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.

The 18-year risk of cancer, angioedema, insomnia, depression, and erectile dysfunction in association with antihypertensive drugs: post-trial analyses from ALLHAT-Medicare linked data

Purpose

This study aimed to determine the 18-year risk of cancer, angioedema, insomnia, depression, and erectile dysfunction in association with antihypertensive drug use.

Methods

This is a post-trial passive follow-up study of Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants between 1994 and 1998 that was conducted by linking their follow-up data with Medicare claims data until 2017 of subjects who were free of outcomes at baseline on 1 January 1999. The main outcomes were the occurrence of cancer (among n = 17,332), angioedema (among n = 17,340), insomnia (among n = 17,340), depression (among n = 17,330), and erectile dysfunction (among n = 7,444 men) over 18 years of follow-up.

Results

The 18-year cumulative incidence rate of cancer other than non-melanoma skin cancer from Medicare inpatient claims was 23.9% for chlorthalidone, 23.4% for amlodipine, and 25.3% for lisinopril. There were no statistically significant differences in the 18-year risk of cancer, depression, and erectile dysfunction among the three drugs based on the adjusted hazard ratios. The adjusted 18-year risk of angioedema was elevated in those receiving lisinopril than in those receiving amlodipine (hazard ratio: 1.63, 95% CI: 1.14-2.33) or in those receiving chlorthalidone (1.33, 1.00-1.79), whereas the adjusted 18-year risk of insomnia was statistically significantly decreased in those receiving lisinopril than in those receiving amlodipine (0.90, 0.81-1.00).

Conclusions

The 18-year risk of angioedema was significantly higher in patients receiving lisinopril than in those receiving amlodipine or chlorthalidone; the risk of insomnia was significantly lower in patients receiving lisinopril than in those receiving amlodipine; and the risk of cancer, depression, and erectile dysfunction (in men) was not statistically significantly different among the three drug groups.

Integrating, Harmonizing, and Curating Studies With High-Frequency and Hourly Physiological Data: Proof of Concept from Seven Traumatic Brain Injury Data Sets

Research in severe traumatic brain injury (TBI) has historically been limited by studies with relatively small sample sizes that result in low power to detect small, yet clinically meaningful outcomes. Data sharing and integration from existing sources hold promise to yield larger more robust sample sizes that improve the potential signal and generalizability of important research questions. However, curation and harmonization of data of different types and of disparate provenance is challenging. We report our approach and experience integrating multiple TBI data sets containing collected physiological data, including both expected and unexpected challenges encountered in the integration process. Our harmonized data set included data on 1536 patients from the Citicoline Brain Injury Treatment Trial (COBRIT), Effect of erythropoietin and transfusion threshold on neurological recovery after traumatic brain injury: a randomized clinical trial (EPO Severe TBI), BEST-TRIP, Progesterone for the Treatment of Traumatic Brain Injury III Clinical Trial (ProTECT III), Transforming Research and Clinical Knowledge in Traumatic brain Injury (TRACK-TBI), Brain Oxygen Optimization in Severe Traumatic Brain Injury Phase-II (BOOST-2), and Ben Taub General Hospital (BTGH) Research Database studies. We conclude with process recommendations for data acquisition for future prospective studies to aid integration of these data with existing studies. These recommendations include using common data elements whenever possible, a standardized recording system for labeling and timing of high-frequency physiological data, and secondary use of studies in systems such as Federal Interagency Traumatic Brain Injury Research Informatics System (FITBIR), to engage investigators who collected the original data.

Occupation and Risk of Traumatic Brain Injury in the Millennium Cohort Study

INTRODUCTION

Traumatic brain injury (TBI) is an occupational health hazard of military service. Few studies have examined differences in military occupational categories (MOC) which take into consideration the physical demands and job requirements across occupational groups.

METHODS

This study was approved by the University of Texas Health Science Center at Houston Institutional Review Board. Data for this cross-sectional study were obtained from the Naval Health Research Center's Millennium Cohort Study, an ongoing DoD study. Univariate analyses were employed to calculate frequencies and proportions for all variables. Bivariate analyses included unadjusted odds ratios (OR) and 95% CI for the association between all variables and TBI. Multivariable logistic regression was used to calculate adjusted ORs and 95% CIs to assess the association between MOC and TBI, adjusted for potential confounders: sex, race/ethnicity, rank, military status, branch of service, before-service TBI, and panel. Logistic regression models estimated odds of TBI for each MOC, and stratified models estimated odds separately for enlisted and officer MOCs.

RESULTS

Approximately 27% of all participants reported experiencing a service-related TBI. All MOCs were statistically significantly associated with increased odds of service-related TBI, with a range of 16 to 45%, except for "Health Care" MOCs (OR: 1.01, 95% CI 0.91-1.13). Service members in "Infantry/Tactical Operations" had the highest odds (OR: 1.45, 95% CI 1.31-1.61) of service-related TBI as compared to "Administration & Executives." Among enlisted service members, approximately 28% reported experiencing a service-related TBI. Among enlisted-specific MOCs, the odds of TBI were elevated for those serving in "Infantry, Gun Crews, Seamanship (OR: 1.79, 95% CI 1.58-2.02)," followed by "Electrical/Mechanical Equipment Repairers (OR: 1.23, 95% CI 1.09-1.38)," "Service & Supply Handlers (OR 1.21, 95% CI 1.08-1.37)," "Other Technical & Allied Specialists (OR 1.21, 95% CI 1.02-1.43)," "Health Care Specialists (OR 1.19, 95% CI 1.04-1.36)," and "Communications & Intelligence (OR: 1.16, 95% CI 1.02-1.31)," compared to "Functional Support & Administration." Among officer service members, approximately 24% reported experiencing a service-related TBI. After adjustment the odds of TBI were found to be significant for those serving as "Health Care Officers" (OR: 0.65, 95% CI: 0.52-0.80) and "Intelligence Officers" (OR: 1.27, 95% CI: 1.01-1.61).

CONCLUSIONS

A strength of this analysis is the breakdown of MOC associations with TBI stratified by enlisted and officer ranks, which has been previously unreported. Given the significantly increased odds of service-related TBI reporting within enlisted ranks, further exploration into the location (deployed versus non-deployed) and mechanism (e.g., blast, training, sports, etc.) for these injuries is needed. Understanding injury patterns within these military occupations is necessary to increase TBI identification, treatment, and foremost, prevention.Results highlight the importance of examining specific occupational categories rather than relying on gross categorizations, which do not account for shared knowledge, skills, and abilities within occupations. The quantification of risk among enlisted MOCs suggests a need for further research into the causes of TBI.

Abstract WP54: Factors Associated With First Year Inpatient And Outpatient Rehabilitation Use Among Acute Ischemic Stroke Patients

Introduction: Stroke is a leading cause of long-term disability in the U.S., and 90% of stroke survivors have residual movement impairment. Inpatient and outpatient rehabilitation is critical for restoring functionality and quality of life among survivors. However, there are few studies evaluating the patterns and predictors of rehabilitation use among stroke survivors.

Methods: This study used 947 tPA-eligibe patients from an observational, prospective, multicenter, clinical trial in the U.S., who had complete 1 year follow-up utilization data, collected quarterly as self-reported surveys. We determined the occurrence and length of stay for inpatient rehabilitation, and occurrence and number of visits for outpatient rehabilitation. Logistic and linear regressions were used to examine predictors associated with these occurrences and intensities.

Results: The majority of rehabilitation use occurred during the first quarter with 19% and 33% of patients using inpatient and outpatient rehabilitation respectively, and rehabilitation use fell considerably over the rest of the year (Table 1). Higher disability at baseline (mRS≥2 and not living at home) reduced rehabilitation use, and higher disability at discharge increased rehabilitation use. Being uninsured reduced rehabilitation use. Other socio-demographic characteristics (such as age, gender and race-ethnicity), baseline comorbidities, and type and timeliness of therapies after stroke did not have an effect on rehabilitation use.

Conclusion: Rehabilitation use is highest during the first 3 months after discharge. Patients with higher discharge disability are more in need of rehabilitation, hence receive it. Patients already disabled at baseline are often excluded, probably due to a combination of rehabilitation entry requirements and perceived lack of potential benefits. Access barriers, such as lack of insurance reduced rehabilitation use suggesting an unmet need among stroke survivors.

Golden Hour Treatment With tPA (Tissue-Type Plasminogen Activator) in the BEST-MSU Study

BACKGROUND

Treatment of patients with acute ischemic stroke on mobile stroke units (MSUs) improves outcomes compared with management by standard emergency medical services ambulances and is associated with more patients treated with intravenous tPA (tissue-type plasminogen activator) in the first golden hour after last known normal. We explored the predictors and outcomes of first-hour treatment (FHT) compared with later treatment in an alternating-week cluster-controlled trial of MSUs.

METHODS

We analyzed all patients treated with intravenous tPA in the BEST-MSU Study (Benefits of Stroke Treatment Delivered by a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services). After stratifying by treatment timeframe, we identified factors associated with FHT. We performed adjusted analyses of the association between FHT and clinical outcome and modeled the shape of the relationship between last known normal-to-treatment time and excellent outcome.

RESULTS

Among 941 tPA-treated patients, 206 (21.8%) had lytic started within 60 minutes. Treatment on the MSU, older age, male sex, alert by 911, faster arrival on-scene and imaging, more severe stroke, atrial fibrillation, and absence of heart failure and pretreatment antihypertensive treatment were associated with FHT. Compared with later treatment, FHT was associated with higher adjusted odds ratio for 90-day modified Rankin Scale score of 0 to 1 (odds ratio, 1.87 [95% CI, 1.25-2.84]; P=0.003). Among FHT patients, 68% achieved a 90-day modified Rankin Scale of 0 or 1 or returned to their baseline status. FHT was not associated with higher risk of hemorrhage and was associated with reduced risk of treating neurovascular mimics.

CONCLUSIONS

FHT almost doubles the odds of excellent clinical outcome without increased risk compared with later treatment, which supports the use of MSUs.

Abstract WP6: Strokes Averted by Intravenous Thrombolysis: A Secondary Analysis of the BEST-MSU Trial

Introduction: While the goal of IV tissue plasminogen activator (TPA) is to prevent infarction, few data exist on averted stroke.

Methods: Secondary analysis of a multicenter trial from 2014-2020 comparing outcomes between patients treated for stroke by mobile stroke unit (MSU) vs standard care (SC). The analytical cohort were patients with suspected stroke treated with IV TPA. The primary outcome was a time-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours. The secondary outcome was a tissue-defined averted stroke diagnosis, defined as a final diagnosis of stroke with resolution of presenting symptoms/signs by 24 hours and no acute infarction/hemorrhage on imaging. We used multivariable logistic regression to evaluate associations between study exposures (demographics, comorbidities, stroke characteristics) and outcomes.

Results: Among 1009 patients with a median last known well-to-TPA time of 87 minutes, 276 patients (27%) had a time-defined averted stroke (31% MSU, 21% SC) and 159 patients (16%) had a tissue-defined averted stroke (18% MSU, 11% SC). Factors independently associated with time-defined averted stroke were younger age (OR, 0.98; 95% CI, 0.96-0.99), female sex (0R, 0.51; 95% CI, 0.36-0.74), hyperlipidemia (OR, 1.81, 95% CI, 1.24-2.64), normal premorbid function (0R, 2.22; 95% CI, 1.37-3.67), lower glucose (OR, 0.996; 95% CI, 0.993-0.999), lower MAP (OR, 0.991; 95% CI, 0.983-0.998), MSU care (OR, 1.77; 95% CI, 1.21-2.62), lower NIH stroke scale (OR, 0.89; 95% CI, 0.86-0.93), and no large vessel occlusion (LVO) (OR, 0.52; 95% CI, 0.32-0.83). For tissue-based averted stroke, younger age, female sex, hyperlipidemia, lower MAP, MSU treatment, lower NIH stroke scale, and no LVO were significantly associated.

Conclusion: In a modern acute stroke trial, one-in-four patients treated with TPA for stroke recovered within 24 hours and one-in-six had no demonstrable brain injury on imaging. Younger age, female sex, hyperlipidemia, lower MAP, MSU care, lower stroke severity, and no LVO may increase the odds of averting stroke.

Abstract WMP2: Acute Stroke Treatment In Patients With Pre-exiting Disability: A Secondary Analysis Of The BEST-MSU Trial

Background: Few data exists on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials.

Methods: A pre-specified subgroup analysis of tPA-eligible patients with PD enrolled in a prospective multicenter trial of Mobile Stroke Units (MSUs) vs standard management by emergency medical services (EMS). All patients had baseline mRS scores. Co-primary outcomes were mean utility-weighted modified Rankin Scale score (uw-mRS) and return to baseline mRS at 90 days. Linear and logistic regression models compared outcomes in patients with vs without PD, and patients with PD treated by MSU vs EMS. Time metrics, safety, quality of life, and health-care utilization were also compared.

Results: Of 1047 patients, 254 had baseline mRS >= 2 (159 MSU, 95 EMS; 31% mRS 2, 52% mRS 3, 17% mRS 4). Compared to patients without disability, patients with PD were older, had higher NIHSS, more comorbidities, less often lived at home, were treated slower, and had less thrombectomy. Patients with PD had worse 90-day uw-mRS (0.39 vs 0.80), higher mortality, more health-care utilization and worse quality of life than patients without PD. However, rates of symptomatic intracranial hemorrhage and final diagnoses of stroke mimics were similar between groups, and 52% of patients with PD returned to their baseline mRS. Patients with PD treated within the first hour had better 90-day uw-mRS than those treated later (0.48 vs 0.36, p=0.01). Comparing patients with PD treated by MSU vs EMS, time from last-known-well to tPA bolus was shorter (82 vs 111 min), and 24% vs 0% were treated in the first hour. Among patients with PD, MSU patients had non-significantly better 90-day uw-mRS (0.41 vs 0.35, p=0.09) and higher rate of returning to baseline mRS (56% vs 44%, p=0.09) than EMS patients. There was no interaction between either time to treatment (p=0.24) or MSU vs EMS group assignment (p= 0.42), 90-day uw-mRS, and PD vs no disability status.

Conclusion: Although outcomes after stroke are less favorable in patients with vs without PD, in a large, controlled trial, we found no interaction between baseline disability and the benefit of MSU treatment. Our data support the earliest treatment of acute stroke patients regardless of premorbid functional status.

Case growth analysis to inform local response to COVID-19 epidemic in a diverse U.S community

Early detection of new outbreak waves is critical for effective and sustained response to the COVID-19 pandemic. We conducted a growth rate analysis using local community and inpatient records from seven hospital systems to characterize distinct phases in SARS-CoV-2 outbreak waves in the Greater Houston area. We determined the transition times from rapid spread of infection in the community to surge in the number of inpatients in local hospitals. We identified 193,237 residents who tested positive for SARS-CoV-2 via molecular testing from April 8, 2020 to June 30, 2021, and 30,031 residents admitted within local healthcare institutions with a positive SARS-CoV-2 test, including emergency cases. We detected two distinct COVID-19 waves: May 12, 2020–September 6, 2020 and September 27, 2020–May 15, 2021; each encompassed four growth phases: lagging, exponential/rapid growth, deceleration, and stationary/linear. Our findings showed that, during early stages of the pandemic, the surge in the number of daily cases in the community preceded that of inpatients admitted to local hospitals by 12–36 days. Rapid decline in hospitalized cases was an early indicator of transition to deceleration in the community. Our real-time analysis informed local pandemic response in one of the largest U.S. metropolitan areas, providing an operationalized framework to support robust real-world surveillance for outbreak preparedness.

Prevalence and Financial Burden of Digestive Diseases in a Commercially Insured Population

BACKGROUND & AIMS

Digestive diseases represent a diverse group of clinical conditions that impact the population. Their heterogeneity in classification, presentation, acuity, chronicity, and need for drug therapy presents a challenge when comparing and contrasting the burden associated with these conditions. Prior studies use an outdated classification system and aggregate costs at the population level or focus on specific diseases, limiting the ability to characterize the overall landscape. Our aim was to provide the most up-to-date assessment of cost, utilization, and prevalence associated with digestive diseases.

METHODS

We examined digestive disease claims and payment data for a commercially insured adult population between 2016 and 2018 to provide a comprehensive summary of costs, utilization, and prevalence across 38 conditions. Outcome variables included point prevalence and relative prevalence, annualized all-cause medical and drug costs, digestive disease-specific average medical cost, digestive disease-specific cost per fill, and utilization by clinical setting and by clinical condition.

RESULTS

A total of 7,297,435 individuals with a digestive disease diagnosis were included in the study. The point prevalence of having a digestive disease in the total population was 24%. Annualized total costs by clinical category ranged from $10,038 (eosinophilic esophagitis) to $107,007 (hepatitis C), with medical costs accounting for most of the expenditures in a majority of conditions. Annualized total costs for common conditions included $39,653 for alcoholic liver disease, $42,554 for acute pancreatitis, $62,735 for Crohn's disease, $13,948 for functional gastrointestinal disorders, $53,214 for nonalcoholic cirrhosis, and $36,441 for ulcerative colitis. Average cost of inpatient stays ranged from $12,218 (noninfectious gastroenteritis/colitis) to $78,259 (nonalcoholic steatohepatitis). Outpatient visits ranged from $784 (gastrointestinal infection) to $4629 (gallbladder and biliary tract disease). Average drug cost per fill ranged from $83 (gastroesophageal reflux disease) to $1458 (hepatitis C). A total of 27,429,046 clinical encounters occurred across all conditions during the study period, with 90% taking place as outpatient visits. Abdominal pain was the single largest contributor to outpatient visits and emergency department to home encounters. Inpatient stays were considerably more heterogeneous, with no condition accounting for more than 12% (gallbladder and biliary tract disease) of the total.

CONCLUSIONS

The results demonstrate digestive diseases are common, heterogeneous in cost and utilization, and collectively exact a significant financial burden on the U.S. adult population.

Trends and Correlates of Breakthrough Infections With SARS-CoV-2

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) delta variant has been hypothesized to decrease the efficacy of COVID-19 vaccines. Factors associated with infections with SARS-CoV-2 after vaccination are unknown. In this observational cohort study, we examined two groups in Harris County, Texas: (1) individuals with positive Nucleic Acid Amplification test between 12/14/2020 and 9/30/2021 and (2) the subset of individuals fully vaccinated in the same time period. Infected individuals were classified as a breakthrough if their infection occurred 14 days after their vaccination had been completed. Among fully vaccinated individuals, demographic and vaccine factors associated with breakthrough infections were assessed. Of 146,731 positive SARS-CoV-2 tests, 7.5% were breakthrough infections. Correlates of breakthrough infection included young adult age, female, White race, and receiving the Janssen vaccine, after adjustments including the amount of community spread at the time of infection. Vaccines remained effective in decreasing the probability of testing positive for SARS-CoV-2. The data indicate that increased vaccine booster uptake would help decrease new infections.

Hemorrhage Enlargement Is More Frequent in the First 2 Hours: A Prehospital Mobile Stroke Unit Study

Background:

Hematoma enlargement (HE) after intracerebral hemorrhage (ICH) is a therapeutic target for improving outcomes. Hemostatic therapies to prevent HE may be more effective the earlier they are attempted. An understanding of HE in first 1 to 2 hours specifically in the prehospital setting would help guide future treatment interventions in this time frame and setting.

Methods:

Patients with spontaneous ICH within 4 hours of symptom onset were prospectively evaluated between May 2014 and April 2020 as a prespecified substudy within a multicenter trial of prehospital mobile stroke unit versus standard management. Baseline computed tomography scans obtained <1, 1 to 2, and 2 to 4 hours postsymptom onset on the mobile stroke unit in the prehospital setting were compared with computed tomography scans repeated 1 hour later and at 24 hours in the hospital. HE was defined as >6 mL if baseline ICH volume was < 20 mL and 33% increase if baseline volume >20 mL. The association between time from symptom onset to baseline computed tomography (hours) and HE was investigated using Wilcoxon rank-sum test when time was treated as a continuous variable and using Fisher exact test when time was categorized. Kruskal-Wallis and Wilcoxon rank-sum tests evaluated differences in baseline volumes and HE. Univariable and multivariable logistic regression analyses were conducted to identify factors associated with HE and variable selection was performed using cross-validated L1-regularized (Lasso regression). This study adhered to STROBE guidelines (Strengthening the Reporting of Observational Studies in Epidemiology) for cohort studies.

Results:

One hundred thirty-nine patients were included. There was no difference between baseline ICH volumes obtained <1 hour (n=43) versus 1 to 2 hour (n=51) versus >2 hours (n=45) from symptom onset (median [interquartile range], 13 mL [6–24] versus 14 mL [6–30] versus 12 mL [4–19]; P =0.65). However, within the same 3 time epochs, initial hematoma growth (volume/time from onset) was greater with earlier baseline scanning (median [interquartile range], 17 mL/hour [9–35] versus 9 mL/hour [5–23]) versus 4 mL/hour [2–7]; P <0.001). Forty-nine patients had repeat scans 1 hour after baseline imaging (median, 2.3 hours [interquartile range. 1.9–3.1] after symptom onset). Eight patients (16%) had HE during that 1-hour interval; all of these occurred in patients with baseline imaging within 2 hours of onset (5/18=28% with baseline imaging within 1 hour, 3/18=17% within 1–2 hour, 0/13=0% >2 hours; P =0.02). HE did not occur between the scans repeated at 1 hour and 24 hours. No association between baseline variables and HE was detected in multivariable analyses.

Conclusions:

HE in the next hour occurs in 28% of ICH patients with baseline imaging within the first hour after symptom onset, and in 17% of those with baseline imaging between 1 and 2 hours. These patients would be a target for ultraearly hemostatic intervention.

Comparison of Mobile Stroke Unit With Usual Care for Acute Ischemic Stroke Management: A Systematic Review and Meta-analysis

IMPORTANCE

So far, uncertainty remains as to whether there is sufficient cumulative evidence that mobile stroke unit (MSU; specialized ambulance equipped with computed tomography scanner, point-of-care laboratory, and neurological expertise) use leads to better functional outcomes compared with usual care.

OBJECTIVE

To determine with a systematic review and meta-analysis of the literature whether MSU use is associated with better functional outcomes in patients with acute ischemic stroke (AIS).

DATA SOURCES

MEDLINE, Cochrane Library, and Embase from 1960 to 2021.

STUDY SELECTION

Studies comparing MSU deployment and usual care for patients with suspected stroke were eligible for analysis, excluding case series and case-control studies.

DATA EXTRACTION AND SYNTHESIS

Independent data extraction by 2 observers, following the PRISMA and MOOSE reporting guidelines. The risk of bias in each study was determined using the ROBINS-I and RoB2 tools. In the case of articles with partially overlapping study populations, unpublished disentangled results were obtained. Data were pooled in random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

The primary outcome was excellent outcome as measured with the modified Rankin Scale (mRS; score of 0 to 1 at 90 days).

RESULTS

Compared with usual care, MSU use was associated with excellent outcome (adjusted odds ratio [OR], 1.64; 95% CI, 1.27-2.13; P < .001; 5 studies; n = 3228), reduced disability over the full range of the mRS (adjusted common OR, 1.39; 95% CI, 1.14-1.70; P = .001; 3 studies; n = 1563), good outcome (mRS score of 0 to 2: crude OR, 1.25; 95% CI, 1.09-1.44; P = .001; 6 studies; n = 3266), shorter onset-to-intravenous thrombolysis (IVT) times (median reduction, 31 minutes [95% CI, 23-39]; P < .001; 13 studies; n = 3322), delivery of IVT (crude OR, 1.83; 95% CI, 1.58-2.12; P < .001; 7 studies; n = 4790), and IVT within 60 minutes of symptom onset (crude OR, 7.71; 95% CI, 4.17-14.25; P < .001; 8 studies; n = 3351). MSU use was not associated with an increased risk of all-cause mortality at 7 days or at 90 days or with higher proportions of symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS AND RELEVANCE

Compared with usual care, MSU use was associated with an approximately 65% increase in the odds of excellent outcome and a 30-minute reduction in onset-to-IVT times, without safety concerns. These results should help guideline writing committees and policy makers.

Abstract TP262: Effect Of Prehospital Blood Pressure Fluctuations On Early Neurological Changes In Acute Ischemic Stroke Patients With Large Vessel Occlusion

Introduction: Blood pressure fluctuations in the acute phase of large vessel occlusion (LVO) ischemic stroke are associated with infarct progression and poor outcomes. We evaluated the association of prehospital blood pressure variations on a Mobile Stroke Unit (MSU) with early neurological change.

Methods: Prospectively-derived data were analyzed from tPA-eligible LVO patients treated and transported on the MSU, identified by hyperdense artery on CT or arterial occlusion on CTA. Patients were categorized by change in mean arterial pressure (ΔMAP) of > 10 mm Hg vs Δ MAP < 10 mmHg from arrival of MSU on-scene to arrival to the emergency department (ED). A sub-analysis of patients with ΔMAP > 10 mm Hg compared those whose MAP decreased by > 10 mm Hg vs those whose MAP increased by > 10 mm Hg. The primary outcome was 24-hour change in NIHSS. Groups were compared using Chi-square/Fisher’s exact test for categorical variables and Wilcoxon rank sum test for continuous variables.

Results: A total of 39 tPA-eligible LVO patients were identified, 19 with ΔMAP < 10mm Hg and 20 with ΔMAP > 10mm Hg. Baseline characteristics were comparable between groups including NIHSS (18.0 [11.0, 21.0] vs 20.0 [16.8, 25.8]) (Table 1). A similar percentage from each group received tPA and thrombectomy. Upon presentation to ED, 7/19 (37%) patients with ΔMAP < 10mm Hg had a 30% improvement in NIHSS, compared to 4/20 (20%) patients with ΔMAP >10mm Hg (p=0.417). The 24-hour change in NIHSS was also similar (ΔMAP < 10mm Hg = 7.0 [3.5, 12.0] vs ΔMAP > 10 mm Hg 10.0 [4.0, 16.0], p=0.517). Among patients with ΔMAP of 10mm Hg group, those with MAP decrease by > 10 mm Hg had a 10 point [7.0, 16.0] improvement in NIHSS vs 6.0 [2.5, 15.0] point improvement in those whose MAP increased by > 10 mm Hg (p=0.169).

Conclusion: Though limited by a small sample size, prehospital blood pressure fluctuations in LVO stroke patients on a MSU were not associated with early clinical changes.

Abstract 24: Mobile Stroke Units Associated With Favorable Clinical Outcome In Large Vessel Occlusion Stroke Patients: BEST-MSU Substudy

Introduction: Mobile Stroke Units (MSUs) improve clinical outcome in patients treated with tPA compared to standard management by Emergency Medical Services (EMS), but the impact of MSUs on outcomes in patients with large vessel occlusions (LVOs) having endovascular thrombectomy (EVT) has yet to be determined.

Methods: A pre-specified substudy of tPA-eligible stroke patients with LVOs on CT and/or CTA who were enrolled in the Benefits of Stroke Treatment Using a Mobile Stroke Unit (BEST-MSU), a prospective multicenter controlled trial comparing MSU with standard EMS management, was conducted. The primary outcome was the score on the 90-day utility-weighted modified Rankin Scale (uw-mRS). Secondary outcomes were rate of early neurologic recovery (30% improvement in NIHSS score) at 24 hours and functional independence (mRS 0-1) at 90 days.

Results: A total of 295 patients were included, 169 in the MSU group and 126 in the EMS group. Baseline characteristics were comparable between the groups, with the exception of baseline NIHSS (MSU median 19.0 [IQR 13.0, 23.0] vs EMS 16.0 [11.0, 20.0], p=0.003). 92% MSU vs 87% EMS LVO patients received tPA, and 78% vs 85% went on to have EVT. MSU LVO patients had faster tPA bolus from symptom onset (65.0 min [50.5, 92.0] vs 96.0 [79.3, 130.0], p<0.001), however the two groups had similar onset to groin puncture (169.0 min [133.8, 212.3] vs 162.0 [135.3, 207.0], p=0.77). The mean (±SD) score on the uw-mRS at 90 days was 0.64±0.39 in the MSU group and 0.50±0.40 in the EMS group (mean difference 0.16, 95% CI [0.07, 0.25] after adjustment for age, baseline NIHSS, premorbid functional status, prior stroke/TIA and site; p<0.001). Early neurologic recovery (68% vs 52%; adjusted OR 1.89 95% CI [1.14,3.17]) and functional independence (Figure 1, 42% vs 29%; 2.48 [1.38,4.55]) also favored the MSU group.

Conclusions: In tPA-eligible LVO stroke patients, MSU management was associated with better clinical outcomes compared with standard EMS management.

Examining Social Vulnerability and the Association With COVID-19 Incidence in Harris County, Texas

Studies have investigated the association between social vulnerability and SARS-CoV-2 incidence. However, few studies have examined small geographic units such as census tracts, examined geographic regions with large numbers of Hispanic and Black populations, controlled for testing rates, and incorporated stay-at-home measures into their analyses. Understanding the relationship between social vulnerability and SARS-CoV-2 incidence is critical to understanding the interplay between social determinants and implementing risk mitigation guidelines to curtail the spread of infectious diseases. The objective of this study was to examine the relationship between CDC's Social Vulnerability Index (SVI) and SARS-CoV-2 incidence while controlling for testing rates and the proportion of those who stayed completely at home among 783 Harris County, Texas census tracts. SARS-CoV-2 incidence data were collected between May 15 and October 1, 2020. The SVI and its themes were the primary exposures. Median percent time at home was used as a covariate to measure the effect of staying at home on the association between social vulnerability and SARS-CoV-2 incidence. Data were analyzed using Kruskal Wallis and negative binomial regressions (NBR) controlling for testing rates and staying at home. Results showed that a unit increase in the SVI score and the SVI themes were associated with significant increases in SARS-CoV-2 incidence. The incidence risk ratio (IRR) was 1.090 (95% CI, 1.082, 1.098) for the overall SVI; 1.107 (95% CI, 1.098, 1.115) for minority status/language; 1.090 (95% CI, 1.083, 1.098) for socioeconomic; 1.060 (95% CI, 1.050, 1.071) for household composition/disability, and 1.057 (95% CI, 1.047, 1.066) for housing type/transportation. When controlling for stay-at-home, the association between SVI themes and SARS-CoV-2 incidence remained significant. In the NBR model that included all four SVI themes, only the socioeconomic and minority status/language themes remained significantly associated with SARS-CoV-2 incidence. Community-level infections were not explained by a communities' inability to stay at home. These findings suggest that community-level social vulnerability, such as socioeconomic status, language barriers, use of public transportation, and housing density may play a role in the risk of SARS-CoV-2 infection regardless of the ability of some communities to stay at home because of the need to work or other reasons.

Development and Feasibility Testing of CATCH Healthy Smiles, an Oral Health Promotion Intervention for Prevention of Dental Caries Among Elementary School Children

BACKGROUND

We present results of the development and feasibility testing of CATCH Healthy Smiles, a school-based oral health program, among children in grades K-2 in Houston, Texas.

METHODS

Study design was cross-sectional (N = 2 schools; N = 125 parent-child dyads; 31 kindergarteners, 42 first graders, and 52 second graders). CATCH Healthy Smiles program was implemented by trained school teachers in the 2016-2017 school year. Trained dentists conducted dental assessments to measure dental caries increment score (d3mfs). Parent-reported 24-hour dietary recalls and surveys assessed child and parent behavioral, environmental, and psychosocial factors. Logistic regression analysis assessed factors associated with caries experience adjusting for covariates.

RESULTS

Of the 113 children with complete dental assessments, 54% children in grade K, 62% in first grade, and 73% in second grade had caries experience. Children with caries experience had a higher body weight (AdjOR = 1.13, 95% confidence interval [CI]: 1.02-1.29), were less likely to be girls (AdjOR = 0.22, 95% CI: 0.05-0.82), had greater odds of difficulty drinking hot or cold beverages because of dental problems (AdjOR = 13.13, 95% CI: 1.09-275.14), greater frequency of consuming sugar-sweetened beverages (AdjOR = 11.53, 95% CI: 2.10-87.19), greater odds of receiving government assistance (AdjOR = 14.62, 95% CI: 2.74-119.81), and lower odds of seeing a dental provider (AdjOR = 0.11, 95% CI: 0.02-0.45). Process evaluation showed that 100% of the CATCH Healthy Smiles lessons and activities were taught in the two schools with a high degree of program fidelity and acceptability across the schools, children, and parents.

CONCLUSIONS

These data will be used to conduct a subsequent fully powered cluster randomized controlled trial.

Machine Learning Automated Detection of Large Vessel Occlusion From Mobile Stroke Unit Computed Tomography Angiography

BACKGROUND AND PURPOSE

Prehospital automated large vessel occlusion (LVO) detection in Mobile Stroke Units (MSUs) could accelerate identification and treatment of patients with LVO acute ischemic stroke. Here, we evaluate the performance of a machine learning (ML) model on CT angiograms (CTAs) obtained from 2 MSUs to detect LVO.

METHODS

Patients evaluated on MSUs in Houston and Los Angeles with out-of-hospital CTAs were identified. Anterior circulation LVO was defined as an occlusion of the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery vessels and determined by an expert human reader. A ML model to detect LVO was trained and tested on independent data sets consisting of in-hospital CTAs and then tested on MSU CTA images. Model performance was determined using area under the receiver-operator curve statistics.

RESULTS

Among 68 patients with out-of-hospital MSU CTAs, 40% had an LVO. The most common occlusion location was the middle cerebral artery M1 segment (59%), followed by the internal carotid artery (30%), and middle cerebral artery M2 (11%). Median time from last known well to CTA imaging was 88.0 (interquartile range, 59.5-196.0) minutes. After training on 870 in-hospital CTAs, the ML model performed well in identifying LVO in a separate in-hospital data set of 441 images with area under receiver-operator curve of 0.84 (95% CI, 0.80-0.87). ML algorithm analysis time was under 1 minute. The performance of the ML model on the MSU CTA images was comparable with area under receiver-operator curve 0.80 (95% CI, 0.71-0.89). There was no significant difference in performance between the Houston and Los Angeles MSU CTA cohorts.

CONCLUSIONS

In this study of patients evaluated on MSUs in 2 cities, a ML algorithm was able to accurately and rapidly detect LVO using prehospital CTA acquisitions.

Retrospectively Collected EQ-5D-5L Data as Valid Proxies for Imputing Missing Information in Longitudinal Studies

OBJECTIVES

Studies face challenges with missing 5-level EQ-5D (EQ-5D-5L) data, often because of the need for longitudinal EQ-5D-5L data collection. There is a dearth of validated methodologies for dealing with missing EQ-5D-5L data in the literature. This study, for the first time, examined the possibility of using retrospectively collected EQ-5D-5L data as proxies for the missing data.

METHODS

Participants who had prospectively completed a 3rd month postdischarge EQ-5D-5L instrument (in-the-moment collection) were randomly interviewed to respond to a 2nd "retrospective collection" of their 3rd month EQ-5D-5L at 6th, 9th, or 12th month after hospital discharge. A longitudinal single imputation was also used to assess the relative performance of retrospective collection compared with the longitudinal single imputation. Concordances between the in-the-moment, retrospective, and imputed measures were assessed using intraclass correlation coefficients and weighted kappa statistics.

RESULTS

Considerable agreement was observed on the basis of weighted kappa (range 0.72-0.95) between the mobility, self-care, and usual activities dimensions of EQ-5D-5L collected in-the-moment and retrospectively. Concordance based on intraclass correlation coefficients was good to excellent (range 0.79-0.81) for utility indices computed, and excellent (range 0.93-0.96) for quality-adjusted life-years computed using in-the-moment compared with retrospective EQ-5D-5L. The longitudinal single imputation did not perform as well as the retrospective collection method.

CONCLUSIONS

This study demonstrates that retrospective collection of EQ-5D-5L has high concordance with "in-the-moment" EQ-5D-5L and could be a valid and attractive alternative for data imputation when longitudinally collected EQ-5D-5L data are missing. Future studies examining this method for other disease areas and populations are required to provide more generalizable evidence.

Prognostic Research in Traumatic Brain Injury: Markers, Modeling, and Methodological Principles

Prognostic assessment in traumatic brain injury (TBI) is embedded deeply in clinical care. Considering the limitations of current prognostic indicators, there is increasing interest in understanding the role of new biomarkers, and in finding other prognostic indicators of long-term outcomes following TBI. New prognostic indicators may result in the development of more accurate prediction models that could be useful for both risk stratification and clinical decision making. We aimed to review methodological issues and provide tentative guidelines for prognostic research in TBI. Prognostic factor research focuses on the role of a specific patient or disease-related characteristic in relation to outcome. Typically, univariable relations of the prognostic factor are studied, followed by analyses adjusting for other variables related to the outcome. Following existing guidelines, we emphasize the importance of transparent reporting of patient and specimen characteristics, study design, clinical end-points, and statistical analysis. Prognostic model research considers combinations of predictors, with challenges for model specification, estimation, evaluation, validation, and presentation. We highlight modern approaches and opportunities related to missing values, exploration of non-linear effects, and assessing between-study heterogeneity. Prognostic research in TBI can be improved if key methodological principles are adhered to and when research is performed in collaboration among multiple centers to ensure generalizability.

Prospective, Multicenter, Controlled Trial of Mobile Stroke Units

BACKGROUND

Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

METHODS

In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients.

RESULTS

We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group.

CONCLUSIONS

In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).

Dosing Tissue Plasminogen Activator on a Mobile Stroke Unit: Comparison Between Estimated and Hospital-Measured Weights

ABSTRACT

BACKGROUND: Prehospital tissue plasminogen activator dosing in a mobile stroke unit (MSU) is estimated by the paramedic and nurse. We aimed to determine the accuracy of the estimated weight method compared with the actual weight of patients treated with tissue plasminogen activator on the MSU. METHODS: We prospectively collected the estimated weight used on the MSU for treatment and the first-documented hospital-measured weight (bed scale) within 24 hours of hospital arrival. Median absolute and percent difference in weights were calculated; less than 10% of difference in weights was considered acceptable. To compare the estimated and measured weights, we conducted a Wilcoxon signed rank test and Fisher exact test to explore the association between weight difference of greater than 10% and patient outcomes. RESULTS: Among 337 patients, median estimated and hospital-measured weights were 79.0 kg (interquartile range [IQR], 66.0-94.5) and 78.5 kg (IQR, 65.0-91.7), respectively. The median of the absolute value of the difference in estimated versus measured weight was 2.7 kg (IQR, 0.6-7.6; P < .0001). The median percent difference in weight was 3.6% (IQR, 0.8%-9.4%). The median difference between the tissue plasminogen activator dosage administered on the MSU and the recommended dose based on the actual weight was 1.3 mg (IQR, 0.06-4.8) in absolute value. In 56 patients (16.6% of the entire sample) with overestimation of weight by greater than 10%, there were no symptomatic intracerebral hemorrhages. There was no association between weight difference and discharge modified Rankin score (P = .59). CONCLUSION: Weight estimation on an MSU can lead to similar tissue plasminogen activator dosing for 83.4% of subjects compared with if dosing were determined based on actual weight. Weight overestimation or underestimation had no detected impact on tissue plasminogen activator outcomes.

Leveraging a health information exchange for analyses of COVID-19 outcomes including an example application using smoking history and mortality

Understanding sociodemographic, behavioral, clinical, and laboratory risk factors in patients diagnosed with COVID-19 is critically important, and requires building large and diverse COVID-19 cohorts with both retrospective information and prospective follow-up. A large Health Information Exchange (HIE) in Southeast Texas, which assembles and shares electronic health information among providers to facilitate patient care, was leveraged to identify COVID-19 patients, create a cohort, and identify risk factors for both favorable and unfavorable outcomes. The initial sample consists of 8,874 COVID-19 patients ascertained from the pandemic's onset to June 12th, 2020 and was created for the analyses shown here. We gathered demographic, lifestyle, laboratory, and clinical data from patient's encounters across the healthcare system. Tobacco use history was examined as a potential risk factor for COVID-19 fatality along with age, gender, race/ethnicity, body mass index (BMI), and number of comorbidities. Of the 8,874 patients included in the cohort, 475 died from COVID-19. Of the 5,356 patients who had information on history of tobacco use, over 26% were current or former tobacco users. Multivariable logistic regression showed that the odds of COVID-19 fatality increased among those who were older (odds ratio = 1.07, 95% CI 1.06, 1.08), male (1.91, 95% CI 1.58, 2.31), and had a history of tobacco use (2.45, 95% CI 1.93, 3.11). History of tobacco use remained significantly associated (1.65, 95% CI 1.27, 2.13) with COVID-19 fatality after adjusting for age, gender, and race/ethnicity. This effort demonstrates the impact of having an HIE to rapidly identify a cohort, aggregate sociodemographic, behavioral, clinical and laboratory data across disparate healthcare providers electronic health record (HER) systems, and follow the cohort over time. These HIE capabilities enable clinical specialists and epidemiologists to conduct outcomes analyses during the current COVID-19 pandemic and beyond. Tobacco use appears to be an important risk factor for COVID-19 related death.

Vasopressor treatment and mortality following nontraumatic subarachnoid hemorrhage: a nationwide electronic health record analysis

OBJECTIVE

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular condition, not only due to the effect of initial hemorrhage, but also due to the complication of delayed cerebral ischemia (DCI). While hypertension facilitated by vasopressors is often initiated to prevent DCI, which vasopressor is most effective in improving outcomes is not known. The objective of this study was to determine associations between initial vasopressor choice and mortality in patients with nontraumatic SAH.

METHODS

The authors conducted a retrospective cohort study using a large, national electronic medical record data set from 2000-2014 to identify patients with a new diagnosis of nontraumatic SAH (based on ICD-9 codes) who were treated with the vasopressors dopamine, phenylephrine, or norepinephrine. The relationship between the initial choice of vasopressor therapy and the primary outcome, which was defined as in-hospital death or discharge to hospice care, was examined.

RESULTS

In total, 2634 patients were identified with nontraumatic SAH who were treated with a vasopressor. In this cohort, the average age was 56.5 years, 63.9% were female, and 36.5% of patients developed the primary outcome. The incidence of the primary outcome was higher in those initially treated with either norepinephrine (47.6%) or dopamine (50.6%) than with phenylephrine (24.5%). After adjusting for possible confounders using propensity score methods, the adjusted OR of the primary outcome was higher with dopamine (OR 2.19, 95% CI 1.70-2.81) and norepinephrine (OR 2.24, 95% CI 1.80-2.80) compared with phenylephrine. Sensitivity analyses using different variable selection procedures, causal inference models, and machine-learning methods confirmed the main findings.

CONCLUSIONS

In patients with nontraumatic SAH, phenylephrine was significantly associated with reduced mortality in SAH patients compared to dopamine or norepinephrine. Prospective randomized clinical studies are warranted to confirm this finding.

Abstract P424: Hemorrhage Enlargement in the First Two Hours: A Mobile Stroke Unit Study

Objective: Hematoma enlargement (HE) occurs after spontaneous intracerebral hemorrhage (ICH) but no studies have evaluated the frequency of HE in first 1-2 h after symptom onset. We evaluated HE in the first 2h after onset using a mobile stroke unit (MSU).

Methods: Patients with spontaneous ICH within 4.5h were evaluated on the Houston MSU between 5/2014 and 4/2020. Baseline CT scans from the MSU were compared with scans repeated within 1h [median 67min (IQR 57-82 min]. Significant HE was defined as >6 ml if baseline volume was <20 ml and 30% increase if baseline volume >20 ml. Kruskal-Wallis and Wilcoxon rank sum tests evaluated differences in baseline volumes and HE. Intraclass correlation coefficient (ICC) evaluated agreement between two ICH measurement techniques (ABC/2 vs semi-automated).

Results: 163 patients had baseline CTs, of whom 60 had repeat 1h CTs (table 1). There was no difference between baseline volume and time of CT from symptom onset {<1h vs 1-2h vs >2h median (IQR) = 14 ml (6-28) vs. 16 ml (7-32) vs. 12 ml (4-24), P=0.42)}. There was also no correlation between time from onset and difference in volume between baseline and 1 h repeat imaging. However, 9/60 patients had significant HE from baseline to 1 h repeat imaging; all of these occurred in patients initially imaged within 2 h of onset (6/24 within 1h, 3/20 within 1-2h) (P=0.03) (figure 1). High reliability was seen between the two methods measuring volumes (ICC = 0.84).

Conclusion: Significant HE in the next hour occurs in 25% of ICH patients imaged within the first hour after symptom onset, and 17% imaged between 1-2 hours of onset. These patients would be a target for ultra-early hemostatic intervention.

Abstract P132: Successful Conduct of an Acute Stroke Clinical Trial During COVID

Introduction: Most clinical research stopped during COVID due to possible impact on data quality and personnel safety. We aimed to assess the impact of COVID on study conduct at sites that continued to enroll patients during the pandemic.

Methods: BEST-MSU is an ongoing study of Mobile Stroke Units (MSU) vs standard management of tPA eligible acute stroke patients in the pre-hospital setting. MSU personnel include a vascular neurologist via telemedicine, and a nurse, CT tech, and medics on board using appropriate PPE. During COVID, consent, 90 d mRS and EQ5D could be obtained by phone instead of in person, otherwise management was the same. We compared patient demographics, study metrics, and infection of study personnel during intra- vs pre-COVID eras.

Results: Four of 6 BEST-MSU sites continued to enroll during COVID. There was no difference in intra- (n= 41) vs pre- (n= 763) COVID enrolled tPA eligible patients’ age, sex, race (45% vs 41% Black), ethnicity (23% vs 19% Hispanic), or NIHSS (12 vs 12). MSU alert frequency did not change, but percent of screened patients enrolled and treated with tPA declined to 12% from 23% (p<.001); enrollment correlated with local stay at home and reopening (fig). There was no difference in alert to MSU arrival or arrival to tPA times, but on-scene time was 2 min longer (p=.04). There was no difference in ED door to CT, tPA, or EVT times, hospital LOS, discharge disposition, or 90d mRS or EQ5D accuracy. One MSU nurse tested positive but did not require medical care.

Conclusion: Clinical research in the pre-hospital setting can be carried out accurately and safely during a pandemic. Study enrollment and tPA treatment rates declined, but otherwise there was no difference in patient demographics, deterioration of study processes, or serious infection of study staff.

Abstract 47: Delaying Admission to Inpatient Rehabilitation Worsens Outcome for Stroke Patients: Detrimental Impact of Covid-19 on Stroke Survivors

Introduction: Inpatient rehabilitation (IPR) is crucial to recovery after stroke. COVID-19, however, has led to delays in post-stroke admission to IPR due to transmission concerns.

Objective: We evaluated the effect of time from stroke onset to IPR admission on post-stroke recovery

Design: A retrospective analysis of 680 patients with acute stroke or intracerebral hemorrhage (ICH), admitted to IPR between APR-2017 and AUG-2019. Association between time from stroke onset to IPR and discharge FIM-Motor Total and FIM-Motor Total with transfers scores was studied, after adjusting for sex, age at onset, stroke severity and type. Multiple linear regression models were conducted for outcomes discharge: (FIM-Motor Total) 2 and (FIM-Motor Total with transfers) 2 ( Table 1) . Square transformations were used to satisfy model assumptions. Ordinal logistic regression models were run for outcomes discharge FIM subset scores categorized as independent (6-7), needs supervision (5), and needs assistance (1-4, reference). The primary variable of interest was days onset to IPR, adjusted for stroke severity (admit FIM subset scores), sex, stroke type and age. ( Table 2). The proportional odds assumption was verified using Brant test.

Results: An inverse relationship was observed between days from onset to IPR and discharge FIM-Motor with and without transfers. Time from stroke onset to IPR admission was associated with decreased discharge FIM-Motor and FIM-Motor with transfers, after adjusting for other covariates. Among FIM subset discharges, an additional day also resulted in a 2-5% decrease in the odds of being more independent.

Conclusion: Delays to IPR admission result in decreased motor function gains and lower chance of independence. In addition to current community education practices, acute care hospitals and IPR facilities must review their processes to remove delays. These processes include requirements for COVID disease testing and IPR acceptance policies.

Abstract 3: Early Recanalization of Large Vessel Occlusions by tPA on the Mobile Stroke Unit

Introduction: The benefit of intravenous tPA in acute ischemic stroke patients with large vessel occlusions (LVOs) is limited but time dependent. We evaluated pre-hospital treatment with tPA on the Mobile Stroke Unit (MSU) to explore the recanalization rate in patients with LVOs and its effect on clinical improvement upon ED arrival.

Methods: Prospectively derived data were analyzed from patients on the Houston MSU who were treated with tPA and had LVOs identified by hyperdense artery on MSU CT or arterial occlusion on MSU CTA. The primary outcome was early recanalization, categorized as resolution of LVO on repeat vascular imaging in the ED or on emergent angiography versus no recanalization. Secondary outcome was change in baseline NIHSS at 24 hours. Differences in NIHSS were evaluated using Wilcoxon rank sum test with continuity correction.

Results: Seventy-one patients received tPA and had proximal LVOs both in the anterior and posterior circulation. Eleven had recanalization on CTA upon ED arrival (15.5%), while 7 had recanalization on emergent angiography (9.9%). The total early recanalization rate with tPA was 25.4%. Forty-seven patients with persistent LVOs on ED arrival (66.2%) underwent endovascular thrombectomy (EVT). Time from symptom onset (last known normal) to tPA bolus did not differ significantly between the early recanalization vs non-early recanalization groups (64.5 minutes [IQR 43.0-78.5] vs 64.0 minutes [52.5-92.0]; p = 0.41). Early recanalization resulted in greater improvement in baseline to ED arrival NIHSS (median NIHSS change 4.0 [0-11.8] vs 0 [0-3.5]; p = 0.01). There were no differences in ED arrival to 24 hour NIHSS between the early recanalization versus non-early recanalization groups irrespective of EVT.

Conclusions: Recanalization by ED arrival occurs in 25% of LVO patients with tPA treatment on a MSU and was associated with early clinical improvement. Subsequent EVT did not “make up” for the clinical benefit of early recanalization.

Disability Rating Scale in the First Few Weeks After a Severe Traumatic Brain Injury as a Predictor of 6-Month Functional Outcome

BACKGROUND

An early acute marker of long-term neurological outcome would be useful to help guide clinical decision making and therapeutic effectiveness after severe traumatic brain injury (TBI). We investigated the utility of the Disability Rating Scale (DRS) as early as 1 wk after TBI as a predictor of favorable 6-mo Glasgow Outcome Scale extended (GOS-E).

OBJECTIVE

To determine the predictability of a favorable 6-mo GOS-E using the DRS measured during weeks 1 to 4 of injury.

METHODS

The study is a sub analysis of patients enrolled in the Epo Severe TBI Trial (n = 200) to train and validate L1-regularized logistic regression models. DRS was collected at weeks 1 to 4 and GOS-E at 6 mo.

RESULTS

The average area under the receiver operating characteristic curve was 0.82 for the model with baseline demographic and injury severity variables and week 1 DRS and increased to 0.88 when including weekly DRS until week 4.

CONCLUSION

This study suggests that week 1 to 4 DRS may be predictors of favorable 6-mo outcome in severe TBI patients and thus useful both for clinical prognostication as well as surrogate endpoints for adaptive clinical trials.

Successful conduct of an acute stroke clinical trial during COVID

Most clinical research stopped during COVID due to possible impact on data quality and personnel safety. We aimed to assess the impact of COVID on acute stroke clinical trial conduct at sites that continued to enroll patients during the pandemic. BEST-MSU is an ongoing study of Mobile Stroke Units (MSU) vs standard management of tPA-eligible acute stroke patients in the pre-hospital setting. MSU personnel include a vascular neurologist via telemedicine, and a nurse, CT technologist, paramedics and emergency medicine technicians on-board. During COVID, consent, 90-day modified Rankin Scale (mRS) and EQ5D were obtained by phone instead of in-person, but other aspects of management were similar to the pre-COVID period. We compared patient demographics, study metrics, and infection of study personnel during intra- vs pre-COVID eras. Five of 6 BEST-MSU sites continued to enroll during COVID. There were no differences in intra- (n = 57) vs pre- (n = 869) COVID enrolled tPA eligible patients’ age, sex, race (38.6% vs 38.0% Black), ethnicity (15.8% vs 18.6% Hispanic), or NIHSS (median 11 vs 9). The percent of screened patients enrolled and adjudicated tPA eligible declined from 13.6% to 6.6% (p < .001); study enrollment correlated with local stay-at-home and reopening orders. There were no differences in alert to MSU arrival or arrival to tPA times, but MSU on-scene time was 5 min longer (p = .01). There were no differences in ED door to CT, tPA treatment or thrombectomy puncture times, hospital length of stay, discharge disposition, or remote vs in-person 90-day mRS or EQ5D. One MSU nurse tested positive but did not require hospitalization. Clinical research in the pre-hospital setting can be carried out accurately and safely during a pandemic. tPA eligibility rates declined, but otherwise there were no differences in patient demographics, deterioration of study processes, or serious infection of study staff.

Trial registration:NCT02190500

Impact of Initial Imaging Protocol on Likelihood of Endovascular Stroke Therapy

Background and Purpose:

Noncontrast head CT and CT perfusion (CTP) are both used to screen for endovascular stroke therapy (EST), but the impact of imaging strategy on likelihood of EST is undetermined. Here, we examine the influence of CTP utilization on likelihood of EST in patients with large vessel occlusion (LVO).

Methods:

We identified patients with acute ischemic stroke at 4 comprehensive stroke centers. All 4 hospitals had 24/7 CTP and EST capability and were covered by a single physician group (Neurology, NeuroIntervention, NeuroICU). All centers performed noncontrast head CT and CT angiography in the initial evaluation. One center also performed CTP routinely with high CTP utilization (CTP-H), and the others performed CTP optionally with lower utilization (CTP-L). Primary outcome was likelihood of EST. Multivariable logistic regression was used to determine whether facility type (CTP-H versus CTP-L) was associated with EST adjusting for age, prestroke mRS, National Institutes of Health Stroke Scale, Alberta Stroke Program Early CT Score, LVO location, time window, and intravenous tPA (tissue-type plasminogen activator).

Results:

Among 3107 patients with acute ischemic stroke, 715 had LVO, of which 403 (56%) presented to CTP-H and 312 (44%) presented to CTP-L. CTP utilization among LVO patients was greater at CTP-H centers (72% versus 18%, CTP-H versus CTP-L, P <0.01). In univariable analysis, EST rates for patients with LVO were similar between CTP-H versus CTP-L (46% versus 49%). In multivariable analysis, patients with LVO were less likely to undergo EST at CTP-H (odds ratio, 0.59 [0.41–0.85]). This finding was maintained in multiple patient subsets including late time window, anterior circulation LVO, and direct presentation patients. Ninety-day functional independence (odds ratio, 1.04 [0.70–1.54]) was not different, nor were rates of post-EST PH-2 hemorrhage (1% versus 1%).

Conclusions:

We identified an increased likelihood for undergoing EST in centers with lower CTP utilization, which was not associated with worse clinical outcomes or increased hemorrhage. These findings suggest under-treatment bias with routine CTP.

Retrospective collection of 90-day modified Rankin Scale is accurate

BACKGROUND

The 90-day modified Rankin Scale is a widely used outcome after stroke but is sometimes hard to ascertain due to loss to follow-up. Missing outcomes can result in biased and/or inefficient estimates in clinical trials. The aim of this study is to assess the validity of acquiring the 90-day modified Rankin Scale at a later point of time when the patient has been lost at 90 days to impute the missing value.

METHODS

Participants who had prospectively completed a 90-day modified Rankin Scale questionnaire on their own in the Benefits of Stroke Treatment Using a Mobile Stroke Unit study were randomly interviewed to recall the 90-day modified Rankin Scale at 6, 9, or 12 months after hospital discharge over the phone. Concordance between the two scores was assessed using kappa and weighted kappa statistics. Logistic regression was used to identify factors associated with inconsistent reporting of the 90-day modified Rankin Scale.

RESULTS

Substantial agreement was observed between in-the-moment and retrospective 90-day modified Rankin Scale recalled at 6, 9, or 12 months (weighted kappa = 0.93, 95% confidence interval: 0.89-0.98; weighted kappa = 0.93, 95% confidence interval: 0.85-1.00 and weighted kappa = 0.89, 95% confidence interval: 0.82-0.95, respectively).

CONCLUSION

Retrospective recall of 90-day modified Rankin Scale at a later time point is a valid means to impute missing data in stroke clinical trials.

Early versus Late Profiles of Inflammatory Cytokines after Mild Traumatic Brain Injury and Their Association with Neuropsychological Outcomes

Despite pre-clinical evidence for the role of inflammation in traumatic brain injury (TBI), there is limited data on inflammatory biomarkers in mild TBI (mTBI). In this study, we describe the profile of plasma inflammatory cytokines and explore associations between these cytokines and neuropsychological outcomes after mTBI. Patients with mTBI with negative computed tomography and orthopedic injury (OI) controls without mTBI were prospectively recruited from emergency rooms at three trauma centers. Plasma inflammatory cytokine levels were measured from venous whole-blood samples that were collected at enrollment (within 24 h of injury) and at 6 months after injury. Neuropsychological tests were performed at 1 week, 1 month, 3 months, and 6 months after the injury. Multivariate regression analysis was performed to identify associations between inflammatory cytokines and neuropsychological outcomes. A total of 53 mTBI and 24 OI controls were included in this study. The majority of patients were male (62.3%), and injured in motor vehicle accidents (37.7%). Plasma interleukin (IL)-2 (p = 0.01) and IL-6 (p = 0.01) within 24 h post-injury were significantly higher for mTBI patients compared with OI controls. Elevated plasma IL-2 at 24 h was associated with more severe 1-week post-concussive symptoms (p = 0.001). At 6 months, elevated plasma IL-10 was associated with greater depression scores (p = 0.004) and more severe post-traumatic stress disorder (PTSD) symptoms (p = 0.001). Plasma cytokine levels (within 24 h and at 6 months post-injury) were significantly associated with early and late post-concussive symptoms, PTSD, and depression scores after mTBI. These results highlight the potential role of inflammation in the pathophysiology of post-traumatic symptoms after mTBI.

Enhanced dispatch and rendezvous doubles the catchment area and number of patients treated on a mobile stroke unit

INTRODUCTION

Mobile Stroke Units (MSUs) deliver acute stroke treatment on-scene in coordination with Emergency Medical Services (EMS). One criticism of the MSU approach is the limited range of a single MSU. The Houston MSU is evaluating MSU implementation, and we developed a rendezvous approach as an innovative solution to expand the range and number of patients treated.

METHODS

In addition to direct 911 dispatch of our MSU to the scene within our 7-mile catchment area, we empowered more distant EMS units to activate the MSU. We also monitored EMS radio communications to identify possible patients. For these distant patients, the MSU met the EMS unit en route to the stroke center and treated the patient at that intermediate location. The distribution of the distance from MSU base station to site of stroke and time from 911 alert to tissue plasminogen activator (tPA) bolus were compared between patients treated on-scene and by rendezvous using Wilcoxon rank sum test.

RESULTS

Over 4 years, 338 acute ischemic stroke patients were treated with tPA on our MSU. Of these, 169 (50%) were treated on-scene after MSU dispatch at a median of 6.4 miles (IQR 6.4 miles) from MSU base station. 169 (50%) were treated by 'rendezvous' pathway with assessment and treatment of stroke a median of 12.4 miles from base (IQR 5.5 miles) (p< 0.0001). Time (min) from MSU alert to tPA bolus did not differ: 36.0 ± 10.0 for on-scene vs 37.0 ± 10.0 with rendezvous (p=0.65). 13% of patients alerted via direct 911 dispatch were treated vs 44% of rendezvous patients.

CONCLUSION

Adding a rendezvous approach to an MSU dispatch pathway doubles the range of operations and the number of patients treated by an MSU in an urban area, without incurring delay.

Exome sequencing compared with standard genetic tests for critically ill infants with suspected genetic conditions

PURPOSE

As exome sequencing (ES) is increasingly used as a diagnostic tool, we aimed to compare ES with status quo genetic diagnostic workup for infants with suspected genetic disorders in terms of identifying diagnoses, survival, and cost of care.

METHODS

We studied newborns and infants admitted to intensive care with a suspected genetic etiology within the first year of life at a US quaternary-referral children's hospital over 5 years. In this propensity-matched cohort study using electronic medical record data, we compared patients who received ES as part of a diagnostic workup (ES cohort, n = 368) with clinically similar patients who did not receive ES (No-ES cohort, n = 368).

RESULTS

Diagnostic yield (27.4% ES, 25.8% No-ES; p = 0.62) and 1-year survival (80.2% ES, 84.8% No-ES; p = 0.10) were no different between cohorts. ES cohort patients had higher cost of admission, diagnostic investigation, and genetic testing (all p < 0.01).

CONCLUSION

ES did not differ from status quo genetic testing collectively in terms of diagnostic yield or patient survival; however, it had high yield as a single test, led to complementary classes of diagnoses, and was associated with higher costs. Further work is needed to define the most efficient use of diagnostic ES for critically ill newborns and infants.

Mobile Stroke Unit Computed Tomography Angiography Substantially Shortens Door-to-Puncture Time

Background and Purpose- Endovascular thrombectomy (ET) door-to-puncture time (DTPT) is a modifiable metric. One of the most important, yet time-consuming steps, is documentation of large vessel occlusion by computed tomography angiography (CTA). We hypothesized that obtaining CTA on board a Mobile Stroke Unit and direct alert of the ET team shortens DTPT by over 30 minutes. Methods- We compared DTPT between patients having CTA onboard the Mobile Stroke Unit then subsequent ET from September 2018 to November 2019 and patients in Mobile Stroke Unit from August 2014 to August 2018, when onboard CTA was not yet being used. We also correlated DTPT with change in National Institutes of Health Stroke Scale between baseline and 24 hours. Results- Median DTPT was 53.5 (95% CI, 35-67) minutes shorter with onboard CTA and direct ET team notification: 41 minutes (interquartile range, 30.0-63.5) versus 94.5 minutes (interquartile range, 69.8-117.3; P<0.001). Median on-scene time was 31.5 minutes (interquartile range, 28.8-35.5) versus 27.0 minutes (interquartile range, 23.0-31.0) (P<0.001). Shorter DTPT correlated with greater improvement of National Institutes of Health Stroke Scale (correlation=-0.2, P=0.07). Conclusions- Prehospital Mobile Stroke Unit management including on-board CTA and ET team alert substantially shortens DTPT. Registration- URL: https://clinicaltrials.gov; Unique identifier: NCT02190500.

Abstract TP494: Estimated tPA Dosing Weight on a Mobile Stroke Unit: Comparison between Estimated and Hospital-measured Weights

Introduction: The purpose of the Houston Mobile Stroke Unit (MSU) is to expedite stroke care by treating patients in the pre-hospital setting where obtaining a measured body weight, critical for accurate pre-hospital tPA dosing, is challenging and impossible. The paramedic and nurse on the MSU subjectively estimate by assessment (with patient report if possible) the weight for calculating tPA dosing. We aimed to determine the accuracy of the estimated weight method compared to the actual weight of patients treated with tPA on the MSU.

Methods: Data were prospectively collected for MSU tPA-treated patients as part of the BEST-MSU study comparing MSU to standard EMS management. We collected the first-documented hospital-measured weight (bed scale) within 24 hours of hospital arrival, and the estimated weight used on the MSU for treatment. Mean absolute and percent difference in weights were calculated; less than 10% difference in weights was considered acceptable. To compare the estimated and measured weights, we conducted a Wilcoxon signed-rank test. Differences between weights were set as 0 if both weights were above 100kg. Fisher’s exact test was used to explore association between weight difference > 10% and patient outcomes.

Results: Among 337 patients, mean age was 67.8 (15.6) and average measured weight was 81.2 kg (SD 22.3). Median absolute difference in measured versus estimated weight was 2.70 kg (IQR 0.55-7.60), and both weights were significantly different from each other (p value < 0.0001). The average absolute percent difference in weight was 7.04% (SD 9.11%). The absolute mean difference in tPA dosage was 3.49 mg (SD 6.06). Among patients whose estimated and measured weights were not both ≥100 kg, 56 (16.6%) had weight difference >10%. In patients with overestimation of weight by >10%, there were no symptomatic intracerebral hemorrhages. There was no association between weight difference and discharge modified Rankin score (p value = 0.5921).

Conclusion: Weight estimation on a mobile stroke unit can lead to similar tPA dosing for 82% of subjects compared to if dosing were determined based on actual weight. Weight over- or under-estimation had no detected significant impact on tPA outcomes.

Abstract 99: Mobile Stroke Unit CTA and Direct Notification of Interventional Team Shortens Door-to-Puncture Time by One Hour

Introduction: Endovascular thrombectomy (ET) is an effective but time sensitive treatment of acute ischemic stroke. Time from Emergency Department (ED) arrival to start of ET (door-to-puncture time, DTPT) is a modifiable metric. One of the most time consuming steps in prolonging DTPT is identification of large vessel occlusion (LVO) by CT angiography (CTA). BEST-MSU is a prospective multicenter comparative effectiveness study of tPA-eligible patients managed on a mobile stroke unit (MSU) vs Emergency Medical Services (Standard Management, SM). After discovering that DTPT was greater than 60 minutes in both groups at three BEST-MSU centers in 2018, we began to routinely obtain CTA on the MSU and directly alert the ET team at receiving hospitals if a LVO was identified. We hypothesized this would shorten DTPT by over 30 minutes.

Methods: In this single center experience, we compared the median (interquartile range, IQR) DTPT and MSU on-scene time for MSU patients having on-board CTA and then ET from 9/2018 to 7/2019 to corresponding MSU ET patients (excluding any that had on-board CTA) from 8/2014 to 8/2018. All CTAs were completed after tPA bolus and during tPA infusion on a Ceretom 8 slice scanner with OptiStat hand injector. All imaging occurred on-scene with the MSU stationary. Consent was obtained for all patients and strict radiation safety guidelines followed.

Results: 13 consecutive patients having CTA on-board the MSU and then ET were compared to 84 patients in the pre-on-board CTA group. Baseline characteristics including median NIHSS score (20 in both groups) and frequency of tPA (85% on-board CTA vs 89% pre-on-board CTA) were comparable. Median DTPT was 60 minutes shorter with on-board CTA and direct notification of the interventional team from the MSU; 34 minutes (IQR 30-57) vs 94.5 minutes (IQR 69.75-117.25) (p < 0.001). Despite the additional time to obtain the CTA on the MSU, on-scene time was only slightly prolonged and did not offset the reduction in DTPT (on-board CTA 30 minutes (IQR 28-33) vs pre-on-board CTA 27 minutes (IQR 23-31) (p = 0.01).

Conclusion: Pre-hospital identification and notification of LVO by a MSU allows a one hour reduction of DTPT, and can be utilized to establish a direct to angiosuite protocol.

Elicitation of prior probability distributions for a proposed Bayesian randomized clinical trial of whole blood for trauma resuscitation

BACKGROUND

Whole blood trauma resuscitation is conceptually appealing and increasingly used but lacks evidence. A randomized controlled trial is needed but challenging to design. A Bayesian approach might be more efficient and more interpretable than a conventional frequentist design. We report the results on an elicitation meeting to create prior probability distributions to help develop such a trial.

METHODS

In‐person expert elicitation meeting, based on Sheffield Elicitation Framework methodology. We used an interactive graphical tool to elicit the quantities of interest (24‐hour mortality and certainty required). Two rounds were conducted, with an intervening discussion of deidentified responses. Individual responses were aggregated into probability distributions.

RESULTS

Fifteen experts participated. The pooled belief was that the median 24‐hour mortality of trauma patients with hemorrhagic shock treated with component therapy (the current standard of care) was 19% (95% credible interval [CrI], 6%‐45%), and the median 24‐hour mortality of those treated with whole blood, 16% (95% CrI, 5%‐39%). The pooled prior distribution for the relative risk had a median of 0.84 (95% CrI, 0.26‐3.1), indicating that the expert group had a 64% prior belief that whole blood decreases 24‐hour mortality compared to component therapy.

CONCLUSIONS

Experts had moderately strong beliefs that whole blood reduces the 24‐hour mortality of trauma patients with hemorrhagic shock. These data will assist with the design and planning of a Bayesian trial of whole blood resuscitation, which will help to answer a key question in contemporary transfusion practice.

Cervical cytology reproducibility and associated clinical and demographic factors

BACKGROUND

Although the Pap test has been the standard screening method for cervical precancer/cancer detection, it has been criticized for having a relatively low sensitivity and a low reproducibility between pathologists. There is limited knowledge about inter-rater agreement and what clinical and demographic factors are associated with disagreements between pathologists reading the same Pap smear.

METHODS

This study aimed to assess inter- and intra- rater agreement of the Pap smear in 1619 cytologic slides with biopsy confirmation, using kappa statistics. Clinical and demographic factors associated with higher odds of inter-rater agreement were also examined and stratified by histologic diagnosis grade.

RESULTS

Using a five grade classification system, the overall kappa statistics for total, inter-rater, and intra-rater samples were 0.62, 0.57, and 0.88 (unweighted) and 0.83, 0.81, and 0.95 (weighted), respectively. In stratified analyses by histologic grade, total kappas ranged from 0.40 (atypia) to 0.64 (human papilloma virus/CIN 1). Factors such as referral for abnormal Pap test (diagnostic vs screening population), recruiting site, and parity were found to be associated with higher agreement between the two cytologic readings.

CONCLUSIONS

We observed relatively higher levels of agreement compared with other studies. However, variability was considerable and agreement was generally moderate, suggesting that cervical screening test accuracy and reproducibility needs to be improved.

Emergency Department Door-to-Puncture Time Since 2014

Background and Purpose- The impact of a mobile stroke unit (MSU) on access to intraarterial thrombectomy (IAT) is a prespecified BEST-MSU substudy (Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit Compared to Standard Management by Emergency Medical Services). On the MSU, IAT decision-making steps, such as computed tomography, neurological exam, and tPA (tissue-type plasminogen activator) treatment are completed before emergency department arrival. We hypothesized that such pre-ED assessment of potential IAT patients on an MSU improves the time from ED arrival to skin puncture time (door-to-puncture-time, DTPT). Methods- BEST-MSU is a prospective comparative effectiveness study of MSU versus standard management by emergency medical services (EMS). We compared ED DTPT among the following groups of MSU and EMS patients: all IAT patients, IAT patients post-tPA, and IAT patients post-tPA meeting thrombolytic adjudication criteria over the first 4 years of the study. Results- From August 2014 to July 2018, a total of 161 patients underwent IAT. Ninety-four patients presented to the ED via the MSU and 67 by EMS. One hundred forty patients received tPA before IAT, 85 in the MSU arm, and 55 in the EMS arm. One hundred twenty-six patients received tPA within thrombolytic adjudication criteria: 76 MSU and 50 EMS. DTPT in minutes was shorter for MSU patients (all IAT MSU versus EMS 89 versus 99, P=0.01; IAT post-tPA MSU versus EMS 93 versus 100, P=0.03; and IAT post-tPA within adjudicated criteria MSU versus EMS 93 versus 99.5, P=0.03). From 2014 to 2018, DTPT decreased at a faster rate for EMS compared with MSU-managed patients, improving by about an hour. Conclusions- Pre-ED IAT evaluation on an MSU results in faster DTPT compared with arrival by EMS. Since 2014, dramatic improvement in ED IAT metrics has attenuated this difference. However, DTPT in all groups indicates substantial room for improvement.

Glasgow Outcome Scale Measures and Impact on Analysis and Results of a Randomized Clinical Trial of Severe Traumatic Brain Injury

The original unstructured Glasgow Outcome Scale (uGOS) and the newer structured interviews GOS and the Extended GOS (GOS-E) have been used widely as outcomes in severe traumatic brain injury (TBI) trials. We compared outcome categories (ranging from dead [D] to good recovery [GR]) for each measure in a randomized trial of transfusion threshold and the implications of measure choice and analysis methods for the results of the trial. We planned to explore patient symptomology possibly driving any discrepancies between the patient's uGOS and GOS scores. Category correspondence between uGOS and GOS scores occurred in 160 (88.4%) of the 181 analyzed cases. The GOS-E and GOS instruments incorporated more behavioral/cognitive/social and other components, leading to a worse outcome in some cases than for the uGOS. Choice of outcome measure and analysis led to incongruous conclusions. Dichotomizing uGOS into favorable outcome (GR and moderate disability [MD] categories) versus unfavorable (severe disability [SD], vegetative state [VS], and D categories), we observed a significant effect of transfusion threshold (odds ratio [OR] = 0.51, p = 0.03; adjusted OR = 0.40, p = 0.02). For the same dichotomization of GOS and GOS-E, the effect was not statistically significant but the ORs were similar (ORs between 0.57 and 0.68, p > 0.15 for all). An effect was not detected using ordinal logistic regression or sliding dichotomy method for all three measures. Differences in categorizations of subjects between moderate and severe disability among the scales impacted conclusions of the trial. In future studies, particular attention should be given to implementing GOS measures and describing the methodology for how outcomes were ascertained.

Characterizing red blood cell age exposure in massive transfusion therapy: the scalar age of blood index (SBI)

BACKGROUND

The mortality of trauma patients requiring massive transfusion to treat hemorrhagic shock approaches 17% at 24 hours and 26% at 30 days. The use of stored RBCs is limited to less than 42 days, so older RBCs are delivered first to rapidly bleeding trauma patients. Patients who receive a greater quantity of older RBCs may have a higher risk for mortality.

METHODS AND MATERIALS

Characterizing blood age exposure requires accounting for the age of each RBC unit and the quantity of transfused units. To address this challenge, a novel Scalar Age of Blood Index (SBI) that represents the relative distribution of RBCs received is introduced and applied to a secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) randomized controlled trial (NCT01545232, https://clinicaltrials.gov/ct2/show/NCT01545232). The effect of the SBI is assessed on the primary PROPPR outcome, 24-hour and 30-day mortality.

RESULTS

The distributions of blood storage ages successfully maps to a parameter (SBI) that fully defines the blood age curve for each patient. SBI was a significant predictor of 24-hour and 30-day mortality in an adjusted model that had strong predictive ability (odds ratio, 1.15 [1.01-1.29], p = 0.029, C-statistic, 0.81; odds ratio, 1.14 [1.02-1.28], p = 0.019, C-statistic, 0.88, respectively).

CONCLUSION

SBI is a simple scalar metric of blood age that accounts for the relative distribution of RBCs among age categories. Transfusion of older RBCs is associated with 24-hour and 30-day mortality, after adjustment for total units and clinical covariates.

Prognosis of Six-Month Glasgow Outcome Scale in Severe Traumatic Brain Injury Using Hospital Admission Characteristics, Injury Severity Characteristics, and Physiological Monitoring during the First Day Post-Injury

Gold standard prognostic models for long-term outcome in patients with severe traumatic brain injury (TBI) use admission characteristics and are considered useful in some areas but not for clinical practice. In this study, we aimed to build prognostic models for 6-month Glasgow Outcome Score (GOS) in patients with severe TBI, combining baseline characteristics with physiological, treatment, and injury severity data collected during the first 24 h after injury. We used a training dataset of 472 TBI subjects and several data mining algorithms to predict the long-term neurological outcome. Performance of these algorithms was assessed in an independent (test) sample of 158 subjects. The least absolute shrinkage and selection operator (LASSO) led to the highest prediction accuracy (area under the receiving operating characteristic curve = 0.86) in the test set. The most important post-baseline predictor of GOS was the best motor Glasgow Coma Scale (GCS) recorded in the first day post-injury. The LASSO model containing the best motor GCS and baseline variables as predictors outperformed a model with baseline data only. TBI patient physiology of the first day-post-injury did not have a major contribution to patient prognosis six months after injury. In conclusion, 6-month GOS in patients with TBI can be predicted with good accuracy by the end of the first day post-injury, using hospital admission data and information on the best motor GCS achieved during those first 24 h post-injury. Passed the first day after injury, important physiological predictors could emerge from landmark analyses, leading to prediction models of higher accuracy than the one proposed in the current research.

Abstract TMP11: Emergency Room Door-to-Puncture Time Since 2015: Observations From the BEST-MSU Study

Introduction: The impact of a Mobile stroke unit (MSU) on access to Endovascular Thrombectomy (ET) is a pre-specified BEST-MSU sub-study. On the MSU, ET decision-making steps such as CT, neurologic exam, and tPA treatment are completed prior to Emergency Room (ER) arrival. We hypothesized that such pre-ER assessment of potential ET patients on a MSU improves metrics.

Methods: BEST-MSU is a prospective comparative effectiveness study of MSU vs Standard Management by Emergency Medical Services (SM). We compared ER door-to-puncture-time (mins, DTPT) among the following groups of MSU and SM patients: all ET patients (ETP), ET patients post-tPA (ETT), and ET patients post-tPA meeting thrombolytic adjudication criteria (ETTA) over the first four years of the study.

Results: There were 161 ETP (67 SM, 94 MSU), 140 ETT (55 SM, 85 MSU), and 126 ETTA (50 SM, 76 MSU) patients. DTPT was shorter for MSU patients (ETP 89 vs 99, p=0.01; ETT 93 vs 100, p=0.03; ETTA 93 vs 99.5, p=0.03). From 2015 to 2018, DTPT decreased at a faster rate for SM compared with MSU-managed patients, improving by about an hour (Figure).

Conclusion: Pre-ER ET evaluation on a MSU results in faster DTPT. Since 2015, dramatic improvement in ER ET metrics has attenuated this difference. However, DTPT of 90-100 mins in all groups indicates substantial room for improvement.