Effectiveness of an Emergency Department-Based Machine Learning Clinical Decision Support Tool to Prevent Outpatient Falls Among Older Adults: Protocol for a Quasi-Experimental Study

BACKGROUND

Emergency department (ED) providers are important collaborators in preventing falls for older adults because they are often the first health care providers to see a patient after a fall and because at-home falls are often preceded by previous ED visits. Previous work has shown that ED referrals to falls interventions can reduce the risk of an at-home fall by 38%. Screening patients at risk for a fall can be time-consuming and difficult to implement in the ED setting. Machine learning (ML) and clinical decision support (CDS) offer the potential of automating the screening process. However, it remains unclear whether automation of screening and referrals can reduce the risk of future falls among older patients.

OBJECTIVE

The goal of this paper is to describe a research protocol for evaluating the effectiveness of an automated screening and referral intervention. These findings will inform ongoing discussions about the use of ML and artificial intelligence to augment medical decision-making.

METHODS

To assess the effectiveness of our program for patients receiving the falls risk intervention, our primary analysis will be to obtain referral completion rates at 3 different EDs. We will use a quasi-experimental design known as a sharp regression discontinuity with regard to intent-to-treat, since the intervention is administered to patients whose risk score falls above a threshold. A conditional logistic regression model will be built to describe 6-month fall risk at each site as a function of the intervention, patient demographics, and risk score. The odds ratio of a return visit for a fall and the 95% CI will be estimated by comparing those identified as high risk by the ML-based CDS (ML-CDS) and those who were not but had a similar risk profile.

RESULTS

The ML-CDS tool under study has been implemented at 2 of the 3 EDs in our study. As of April 2023, a total of 1326 patient encounters have been flagged for providers, and 339 unique patients have been referred to the mobility and falls clinic. To date, 15% (45/339) of patients have scheduled an appointment with the clinic.

CONCLUSIONS

This study seeks to quantify the impact of an ML-CDS intervention on patient behavior and outcomes. Our end-to-end data set allows for a more meaningful analysis of patient outcomes than other studies focused on interim outcomes, and our multisite implementation plan will demonstrate applicability to a broad population and the possibility to adapt the intervention to other EDs and achieve similar results. Our statistical methodology, regression discontinuity design, allows for causal inference from observational data and a staggered implementation strategy allows for the identification of secular trends that could affect causal associations and allow mitigation as necessary.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05810064; https://www.clinicaltrials.gov/study/NCT05810064.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48128.

Primary Care Patients' and Staff's Perceptions of Self-Rooming as Alternative to Waiting Rooms

PURPOSE

Most patients are escorted to exam rooms (escorted rooming) although patients directing themselves to their exam room (self-rooming) saves patient and staff time while increasing patient satisfaction. This study assesses patient and staff perceptions after pragmatic implementation of self-rooming.

METHODS

In October-December 2020, we surveyed patients and staff in 25 primary care clinics after our institution expanded self-rooming from 4 specially built clinics during the COVID-19 pandemic. Semi-structured surveys asked about rooming process used, rooming process preferred, and perceptions of self-rooming compared with escorted rooming.

RESULTS

Most patients (n = 1,561) preferred self-rooming (86%), especially among patients aged <65 years and in family medicine clinics. Few patients felt less welcomed (10.6%), less cared about (6.8%), more isolated (15.6%), more lost/confused (7.6%), or more frustrated (3.2%) with self-rooming compared with escorted rooming. Early-adopter clinics that implemented self-rooming ≤2016 had even lower rates of patients feeling more isolated, lost/confused, or frustrated with self-rooming compared with escorted rooming.Over one-half of staff (n = 241; 180 clinical, 61 nonclinical) preferred self-rooming (59%) and thought most patients liked self-rooming (65.8%), especially among clinical staff and in early adopter clinics (≤2016). Few staff reported worse waiting times for patients (12.4%), medical assistants (MAs) (15.9%), and clinicians (16.4%) or worse crowding in waiting areas (1.7%) and hallways (10.1%). Unlike patient-reported confusion (7.6%), most staff thought self-rooming led to more patient confusion (63.8%), except in early-adopter clinics (44.4%).

CONCLUSIONS

Self-rooming is a patient-centered innovation that is also acceptable to staff. We demonstrated that pragmatic implementation is feasible across primary care without expensive technology or specially designed buildings.

Does a Change in Physician Compensation Lead to Changes in Care Delivery in Family Medicine Clinics?

BACKGROUND AND OBJECTIVES

Many highly capitated systems still pay physicians based on relative value units (RVU), which may lead to excessive office visits. We reviewed electronic health records from the family medicine clinic panel members of 97 physicians and 42 residents to determine if a change from RVUs to panel-based compensation influenced care delivery as defined by the number of office visits and telephone contacts per panel member per month.

METHODS

A retrospective analysis of the electronic health records of patients seen in 4 residency training clinics, 10 community clinics, and 4 regional clinics was conducted. We assessed face-to-face care delivery and telephone call volume for the clinics individually and for the clinics pooled by clinic type from 1 year before to at least 1 year after the change.

RESULTS

Change in physician compensation was not found to have an effect on office visits or telephone calls per panel member per month when pooled by clinic categories. Some significant effects were seen in individual clinics without any clear patterns by clinic size or type.

CONCLUSIONS

Change in physician compensation was not a key driver of care delivery in family medicine clinics. Understanding changes in care delivery may require looking at a broad array of system, physician, and patient factors.

Collaborative care implementation: lessons learned

The authors drafted a "Shared Values of Collaborative Care" document with fundamental principles to make better group decisions in implementing collaborative care.

Impactability Modeling for Reducing Medicare Accountable Care Organization Payments and Hospital Events in High-Need High-Cost Patients: Longitudinal Cohort Study

Background

Impactability modeling promises to help solve the nationwide crisis in caring for high-need high-cost patients by matching specific case management programs with patients using a “benefit” or “impactability” score, but there are limitations in tailoring each model to a specific program and population.

Objective

We evaluated the impact on Medicare accountable care organization savings from developing a benefit score for patients enrolled in a historic case management program, prospectively implementing the score, and evaluating the results in a new case management program.

Methods

We conducted a longitudinal cohort study of 76,140 patients in a Medicare accountable care organization with multiple before-and-after measures of the outcome, using linked electronic health records and Medicare claims data from 2012 to 2019. There were 489 patients in the historic case management program, with 1550 matched comparison patients, and 830 patients in the new program, with 2368 matched comparison patients. The historic program targeted high-risk patients and assigned a centrally located registered nurse and social worker to each patient. The new program targeted high- and moderate-risk patients and assigned a nurse physically located in a primary care clinic. Our primary outcomes were any unplanned hospital events (admissions, observation stays, and emergency department visits), count of event-days, and Medicare payments.

Results

In the historic program, as expected, high-benefit patients enrolled in case management had fewer events, fewer event-days, and an average US $1.15 million reduction in Medicare payments per 100 patients over the subsequent year when compared with the findings in matched comparison patients. For the new program, high-benefit high-risk patients enrolled in case management had fewer events, while high-benefit moderate-risk patients enrolled in case management did not differ from matched comparison patients.

Conclusions

Although there was evidence that a benefit score could be extended to a new case management program for similar (ie, high-risk) patients, there was no evidence that it could be extended to a moderate-risk population. Extending a score to a new program and population should include evaluation of program outcomes within key subgroups. With increased attention on value-based care, policy makers and measure developers should consider ways to incorporate impactability modeling into program design and evaluation.

Collaborative design and implementation of a clinical decision support system for automated fall-risk identification and referrals in emergency departments

Of the 3 million older adults seeking fall-related emergency care each year, nearly one-third visited the Emergency Department (ED) in the previous 6 months. ED providers have a great opportunity to refer patients for fall prevention services at these initial visits, but lack feasible tools for identifying those at highest-risk. Existing fall screening tools have been poorly adopted due to ED staff/provider burden and lack of workflow integration. To address this, we developed an automated clinical decision support (CDS) system for identifying and referring older adult ED patients at risk of future falls. We engaged an interdisciplinary design team (ED providers, health services researchers, information technology/predictive analytics professionals, and outpatient Falls Clinic staff) to collaboratively develop a system that successfully met user requirements and integrated seamlessly into existing ED workflows. Our rapid-cycle development and evaluation process employed a novel combination of human-centered design, implementation science, and patient experience strategies, facilitating simultaneous design of the CDS tool and intervention implementation strategies. This included defining system requirements, systematically identifying and resolving usability problems, assessing barriers and facilitators to implementation (e.g., data accessibility, lack of time, high patient volumes, appointment availability) from multiple vantage points, and refining protocols for communicating with referred patients at discharge. ED physician, nurse, and patient stakeholders were also engaged through online surveys and user testing. Successful CDS design and implementation required integration of multiple new technologies and processes into existing workflows, necessitating interdisciplinary collaboration from the onset. By using this iterative approach, we were able to design and implement an intervention meeting all project goals. Processes used in this Clinical-IT-Research partnership can be applied to other use cases involving automated risk-stratification, CDS development, and EHR-facilitated care coordination.

Analysis of Health System Size and Variability in Diabetic Eye Disease Screening in Wisconsin

This cohort study uses statewide claims data to assess variability in diabetic eye disease screening across Wisconsin health systems and to examine the association between patient health system and screening receipt.

Estimation and inference on high-dimensional individualized treatment rule in observational data using split-and-pooled de-correlated score

With the increasing adoption of electronic health records, there is an increasing interest in developing individualized treatment rules, which recommend treatments according to patients' characteristics, from large observational data. However, there is a lack of valid inference procedures for such rules developed from this type of data in the presence of high-dimensional covariates. In this work, we develop a penalized doubly robust method to estimate the optimal individualized treatment rule from high-dimensional data. We propose a split-and-pooled de-correlated score to construct hypothesis tests and confidence intervals. Our proposal adopts the data splitting to conquer the slow convergence rate of nuisance parameter estimations, such as non-parametric methods for outcome regression or propensity models. We establish the limiting distributions of the split-and-pooled de-correlated score test and the corresponding one-step estimator in high-dimensional setting. Simulation and real data analysis are conducted to demonstrate the superiority of the proposed method.

Using Statewide Electronic Health Record and Influenza Vaccination Data to Plan and Prioritize COVID-19 Vaccine Outreach and Communications in Wisconsin Communities

The University of Wisconsin Neighborhood Health Partnerships Program used electronic health record and influenza vaccination data to estimate COVID-19 relative mortality risk and potential barriers to vaccination in Wisconsin ZIP Code Tabulation Areas. Data visualization revealed four groupings to use in planning and prioritizing vaccine outreach and communication based on ZIP Code Tabulation Area characteristics. The program provided data, visualization, and guidance to health systems, health departments, nonprofits, and others to support planning targeted outreach approaches to increase COVID-19 vaccination uptake. (Am J Public Health. 2021;111(12):2111-2114. https://doi.org/10.2105/AJPH.2021.306524).

Reinforced risk prediction with budget constraint using irregularly measured data from electronic health records

Uncontrolled glycated hemoglobin (HbA1c) levels are associated with adverse events among complex diabetic patients. These adverse events present serious health risks to affected patients and are associated with significant financial costs. Thus, a high-quality predictive model that could identify high-risk patients so as to inform preventative treatment has the potential to improve patient outcomes while reducing healthcare costs. Because the biomarker information needed to predict risk is costly and burdensome, it is desirable that such a model collect only as much information as is needed on each patient so as to render an accurate prediction. We propose a sequential predictive model that uses accumulating patient longitudinal data to classify patients as: high-risk, low-risk, or uncertain. Patients classified as high-risk are then recommended to receive preventative treatment and those classified as low-risk are recommended to standard care. Patients classified as uncertain are monitored until a high-risk or low-risk determination is made. We construct the model using claims and enrollment files from Medicare, linked with patient Electronic Health Records (EHR) data. The proposed model uses functional principal components to accommodate noisy longitudinal data and weighting to deal with missingness and sampling bias. The proposed method demonstrates higher predictive accuracy and lower cost than competing methods in a series of simulation experiments and application to data on complex patients with diabetes.

Sustaining Gains in Diabetic Eye Screening: Outcomes from a Stakeholder-Based Implementation Program for Teleophthalmology in Primary Care

Background: Teleophthalmology is a validated method for diabetic eye screening that is underutilized in U.S. primary care clinics. Even when made available to patients, its long-term effectiveness for increasing screening rates is often limited. Introduction: We hypothesized that a stakeholder-based implementation program could increase teleophthalmology use and sustain improvements in diabetic eye screening. Materials and Methods:We used the NIATx Model to test a stakeholder-based teleophthalmology implementation program, I-SITE at one primary care clinic (Main) and compared teleophthalmology use and diabetic eye screening rates with those of other primary care clinics (Outreach) within a U.S. multipayer health system where teleophthalmology was underutilized.Results:Teleophthalmology use increased post-I-SITE implementation (odds ratio [OR] = 5.73 [p < 0.001]), and was greater at the Main than at the Outreach clinics (OR = 10.0 vs. 1.69, p < 0.001). Overall diabetic eye screening rates maintained an increase from 47.4% at baseline to 60.2% and 64.1% at 1 and 2 years post-I-SITE implementation, respectively (p < 0.001). Patients who were younger (OR = 0.98 per year of age, p = 0.02) and men (OR = 1.98, p = 0.002) were more likely to use teleophthalmology than in-person dilated eye examinations for diabetic eye screening.Discussion: Our stakeholder-based implementation program achieved a significant increase in overall teleophthalmology use and maintained increased post-teleophthalmology diabetic eye screening rates. Conclusion: Stakeholder-based implementation may increase the long-term reach and effectiveness of teleophthalmology to reduce vision loss from diabetes. Our approach may improve integration of telehealth interventions into primary care.

Eliminating Cervical Cancer: Progress and Challenges for High-income Countries

In 2020, the World Health Organization launched a major initiative to eliminate cervical cancer globally. The initiative is built around the three key pillars of human papillomavirus (HPV) vaccination, cervical screening and treatment, with associated intervention targets for the year 2030. The '90-70-90' targets specify that 90% of adolescent girls receive prophylactic HPV vaccination, 70% of adult women receive a minimum twice-in-a-lifetime cervical HPV test and 90% receive appropriate treatment for preinvasive or invasive disease. Modelling has shown that if these targets are met, the elimination of cervical cancer, defined as fewer than four cases per 100 000 women per annum, will be achieved within a century. Many high-income countries are well positioned to eliminate cervical cancer within the coming decades, but few have achieved '90-70-90' and many challenges must still be addressed to deliver these critical interventions effectively. This review considers the current status of cervical cancer control in relation to each of the three elimination pillars in high-income countries and discusses some of the developments that will assist countries in reaching these ambitious targets by 2030.

Association of continuous positive airway pressure adherence with complications in patients with type 2 diabetes and obstructive sleep apnea

STUDY OBJECTIVES

To explore the association of continuous positive airway pressure (CPAP) adherence with clinical outcomes in patients with type 2 diabetes and obstructive sleep apnea in a real-world setting.

METHODS

This was a retrospective study of patients with type 2 diabetes diagnosed with obstructive sleep apnea between 2010 and 2017. CPAP adherence (usage for ≥ 4 h/night for ≥ 70% of nights) was determined from the first CPAP report following the polysomnography. Data including estimated glomerular filtration rate, hemoglobin A1c, systolic and diastolic blood pressure, lipid panel, and incident cardiovascular/peripheral vascular/cerebrovascular events were extracted from medical records. Mixed-effects linear regression modeling of longitudinal repeated measures within patients was utilized for continuous outcomes, and logistic regression modeling was used for binary outcomes. Models were controlled for age, sex, body mass index, medications, and baseline levels of outcomes.

RESULTS

Of the 1,295 patients, 260 (20.7%) were CPAP adherent, 318 (24.5%) were CPAP nonadherent, and 717 (55.3%) had insufficient data. The follow-up period was, on average, 2.5 (1.7) years. Compared to those who were CPAP nonadherent, those who were adherent had a significantly lower systolic blood pressure (β = -1.95 mm Hg, P = .001) and diastolic blood pressure (β = -2.33 mm Hg, P < .0001). Among the patients who were CPAP adherent, a 17% greater CPAP adherence was associated with a 2 mm Hg lower systolic blood pressure. Lipids, hemoglobin A1c, estimated glomerular filtration rate, and incident cardiovascular/peripheral vascular/cerebrovascular events were not different between the 2 groups.

CONCLUSIONS

Achieving CPAP adherence in patients with type 2 diabetes and obstructive sleep apnea was associated with significantly lower blood pressure. Greater CPAP use within patients who were adherent was associated with lower systolic blood pressure.

CITATION

Sheth U, Monson RS, Prasad B, et al. Association of continuous positive airway pressure adherence with complications in patients with type 2 diabetes and obstructive sleep apnea. J Clin Sleep Med. 2021;17(8):1563-1569.

Identifying Substantial Racial and Ethnic Disparities in Health Outcomes and Care in Wisconsin Using Electronic Health Record Data

BACKGROUND

Our goal was to identify racial and ethnic disparities in health outcome and care measures in Wisconsin.

METHODS

We used electronic health record data from 25 health systems submitting to the Wisconsin Collaborative for Healthcare Quality to identify disparities in measures, including vaccinations, screenings, risk factors for chronic disease, and chronic disease management.

RESULTS

American Indian/Alaska Native and Black populations experienced substantial disparities across multiple measures. Asian/Pacific Islander, Hispanic/Latino, and White populations experienced substantial disparities for 2 measures each.

DISCUSSION

Reducing health disparities is a statewide imperative. Root causes of health disparities, such as systemic racism and socioeconomic factors, should be addressed for groups experiencing multiple disparities, with focused efforts on selected measures when indicated.

Abstract PS9-25: Receipt of preventive care and health promotion in a cohort of early stage breast cancer survivors

Introduction: Prior studies have demonstrated that breast cancer survivors are less likely to receive primary care preventive services than non-cancer patients. However, even recent studies have largely assessed survivors diagnosed over a decade ago. Further, studies have not considered patient receipt of health promotion guidance, critical to maintaining a healthy lifestyle. We examined the receipt of preventive care and health promotion in a modern cohort of early stage breast cancer survivors seen within our breast program. Methods: A cross-sectional cohort of women with a history of stage I/II, hormone receptor +, HER2neu- breast cancer within 5 years from diagnosis who did not receive chemotherapy were consented (n=101). Survivors completed a survey evaluating aspects of survivorship, including provider discussions regarding health promotion. Electronic medical record (EMR) abstraction captured receipt of preventive care (see Table). We excluded survivors with a primary care provider outside our health care system to ensure complete capture of screening (n=36). Results: Our final cohort (n=62) was a median 2 years from diagnosis (range 0.5-5 years) and a median age of 61 years (range 30-84). Most were stage I (73%) and white (95%). The majority of survivors received preventive care (Table). Survivors were less likely to report health promotion guidance from their provider, including: discussing “things you could do to improve your health” (66%), getting “help you wanted to make changes in your habits” (52%), discussing “how much or what kinds of food you eat” (24%), and “how much or what kind of exercise” (42%). Conclusion: In a modern cohort of early stage breast cancer survivors from a single breast center homed within our health care system, documented receipt of preventive care was high (≥75%). These high rates may reflect the implementation of EMRs (which could facilitate care coordination and provide best practice alerts), participation of our health system in state-wide quality improvement programs, and/or heightened awareness of the importance of preventive care by oncology providers. However, survivors perceive limited discussions surrounding health promotion, presenting an opportunity to improve survivorship care.

Table. Summary of Receipt of Preventive Care for Early Stage Breast Cancer SurvivorsRecommended Preventive Care ServicesDefinition of ReceiptProportion of Eligible PatientsInfluenza vaccineAny since diagnosis*76% (44/58)Pneumococcal vaccineIf &gt;65 yo, any since diagnosis*93% (38/41)Lipid screeningAny within 5 years84% (52/62)Colorectal cancer screeningIf &gt;50 yo, colonoscopy within 10 years, cologuard within 5 years, fecal occult test within 1 year77% (37/48)Cervical cancer screeningIf cervix present and &lt;65 yo, within 5 years79% (27/34)Mammogram screeningIf breast tissue present, annual100% (56/56)*if &lt;1 year from diagnosis, ineligible for this metric

Citation Format: Jessica R. Schumacher, James E Haine, Amye J Tevaarwerk, Kristine L Kwekkeboom, Trista J Stankowski-Drengler, Catherine R. Breuer, Jennifer L Tucholka, Courtney Maxcy, Maureen A Smith, Heather B. Neuman. Receipt of preventive care and health promotion in a cohort of early stage breast cancer survivors [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-25.

The importance of health insurance claims data in creating learning health systems: evaluating care for high-need high-cost patients using the National Patient-Centered Clinical Research Network (PCORNet)

OBJECTIVE

Case management programs for high-need high-cost patients are spreading rapidly among health systems. PCORNet has substantial potential to support learning health systems in rapidly evaluating these programs, but access to complete patient data on health care utilization is limited as PCORNet is based on electronic health records not health insurance claims data. Because matching cases to comparison patients on baseline utilization is often a critical component of high-quality observational comparative effectiveness research for high-need high-cost patients, limited access to claims may negatively affect the quality of the matching process. We sought to determine whether the evaluation of programs for high-need high-cost patients required claims data to match cases to comparison patients.

MATERIALS AND METHODS

A retrospective cohort study design with multiple measures of before-and-after health care utilization for 1935 case management patients and 3833 matched comparison patients aged 18 years and older from 2011 to 2015. EHR and claims data were extracted from 3 health systems participating in PCORNet.

RESULTS

Without matching on claims-based health care utilization, the case management programs at 2 of 3 health systems were associated with fewer hospital admissions and emergency visits over the subsequent 12 months. With matching on claims-based health care utilization, case management was no longer associated with admissions and emergency visits at those 2 programs.

DISCUSSION

The results of a PCORNet-facilitated evaluation of 3 programs for high-need high-cost patients differed substantially depending on whether claims data were available for matching cases to comparison patients.

CONCLUSIONS

Partnering with learning health systems to rapidly evaluate programs for high-need high-cost patients will require that PCORNet facilitates comprehensive and timely access to both electronic health records and health insurance claims data.

Retinal ganglion cell loss and gliosis in the retinofugal projection following intravitreal exposure to amyloid-beta

Pathological accumulations of amyloid-beta (Aβ) peptide are found in retina early in Alzheimer's disease, yet its effects on retinal neuronal structure remain unknown. To investigate this, we injected fibrillized Aβ1-42 protein into the eye of adult C57BL/6 J mice and analyzed the retina, optic nerve (ON), and the superior colliculus (SC), the primary retinal target in mice. We found that retinal Aβ exposure stimulated microglial activation and retinal ganglion cell (RGC) loss as early as 1-week post-injection. Pathology was not limited to the retina, but propagated into other areas of the central nervous system. Microgliosis spread throughout the retinal projection (retina, ON, and SC), with multiplex protein quantitation demonstrating an increase in endogenously produced Aβ in the ON and SC corresponding to the injected retinas. Surprisingly, this pathology spread to the opposite side, with unilateral Aβ eye injections driving increased Aβ levels, neuroinflammation, and RGC death in the opposite, un-injected retinal projection. As Aβ-mediated microglial activation has been shown to propagate Aβ pathology, we also investigated the role of the Aβ-binding microglial scavenger receptor CD36 in this pathology. Transgenic mice lacking the CD36 receptor were resistant to Aβ-induced inflammation and RGC death up to 2 weeks following exposure. These results indicate that Aβ pathology drives regional neuropathology in the retina and does not remain isolated to the affected eye, but spreads throughout the nervous system. Further, CD36 may serve as a promising target to prevent Aβ-mediated inflammatory damage.

A practical model for research with learning health systems: Building and implementing effective complex case management

For researchers to contribute meaningfully to the creation of learning health systems, practical tools are required to operationalize existing conceptual frameworks. We describe a model currently in use by the University of Wisconsin Health Innovation Program (HIP). The HIP model consolidates and enhances existing learning health system frameworks by defining specific steps needed to create sustainable change based on research conducted within the health system. As an example of the model's application, we describe its use to improve patient identification for the University of Wisconsin health system's case management program. Our case study shows the importance of culture, infrastructure, and strong leadership support in realizing a learning health systems research project and creating sustainable change within the health system. By articulating the foundational elements and steps to conduct research with learning health systems, our model supports researchers in achieving the challenge of moving learning health systems from concept to action.

Trabecula: A Random Generator of Computational Phantoms for Bone Marrow Dosimetry

This study was motivated by the efforts to evaluate radiation risk for leukemia incidence in the Techa River cohort, where the main bone marrow dose contributors were Sr (bone-seeking beta emitters). Energy deposition in bone marrow targets was evaluated by simulating radiation particle transport using computational phantoms. The present paper describes the computer program Trabecula implementing an algorithm for parametric generation of computational phantoms, which serve as the basis for calculating bone marrow doses. Trabecula is a user-friendly tool that automatically converts analytical models into voxelized representations that are directly compatible as input to Monte Carlo N Particle code.

Enhancements in the Techa River Dosimetry System: TRDS-2016D Code for Reconstruction of Deterministic Estimates of Dose From Environmental Exposures

Waterborne releases to the Techa River from the Mayak plutonium facility in Russia during 1949-1956 resulted in significant doses to persons living downstream. The dosimetry system Techa River Dosimetry System-2016D has been developed, which provides individual doses of external and internal exposure for the members of the Techa River cohort and other persons who were exposed to releases of radioactive material to the Southern Urals. The results of computation of individual doses absorbed in red bone marrow and extraskeletal tissues for the Techa River cohort members (29,647 persons) are presented, which are based on residence histories on the contaminated Techa River and the East Urals Radioactive Trace, which was formed in 1957 as a result of the Kyshtym Accident. Available Sr body-burden measurements and available information on individual household locations have been used for refinement of individual dose estimates. Techa River Dosimetry System-2016D-based dose estimates will be used for verification of risk of low-dose-rate effects of ionizing radiation in the Techa River cohort.

Training and Interpreting Machine Learning Algorithms to Evaluate Fall Risk After Emergency Department Visits

BACKGROUND

Machine learning is increasingly used for risk stratification in health care. Achieving accurate predictive models do not improve outcomes if they cannot be translated into efficacious intervention. Here we examine the potential utility of automated risk stratification and referral intervention to screen older adults for fall risk after emergency department (ED) visits.

OBJECTIVE

This study evaluated several machine learning methodologies for the creation of a risk stratification algorithm using electronic health record data and estimated the effects of a resultant intervention based on algorithm performance in test data.

METHODS

Data available at the time of ED discharge were retrospectively collected and separated into training and test datasets. Algorithms were developed to predict the outcome of a return visit for fall within 6 months of an ED index visit. Models included random forests, AdaBoost, and regression-based methods. We evaluated models both by the area under the receiver operating characteristic (ROC) curve, also referred to as area under the curve (AUC), and by projected clinical impact, estimating number needed to treat (NNT) and referrals per week for a fall risk intervention.

RESULTS

The random forest model achieved an AUC of 0.78, with slightly lower performance in regression-based models. Algorithms with similar performance, when evaluated by AUC, differed when placed into a clinical context with the defined task of estimated NNT in a real-world scenario.

CONCLUSION

The ability to translate the results of our analysis to the potential tradeoff between referral numbers and NNT offers decisionmakers the ability to envision the effects of a proposed intervention before implementation.

Natural killer cell expression of Ki67 is associated with elevated serum IL-15, disease activity and nephritis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder whose pathology involves multiple immune cell types, including B and T lymphocytes as well as myeloid cells. While it is clear that autoantibody-producing B cells, as well as CD4⁺ T cell help, are key contributors to disease, little is known regarding the role of innate lymphoid cells such as natural killer (NK) cells in the pathogenesis of SLE. We have characterized the phenotype of NK cells by multi-color flow cytometry in a large cohort of SLE patients. While the overall percentage of NK cells was similar or slightly decreased compared to healthy controls, a subset of patients displayed a high frequency of NK cells expressing the proliferation marker, Ki67, which was not found in healthy donors. Although expression of Ki67 on NK cells correlated with Ki67 on other immune cell subsets, the frequency of Ki67 on NK cells was considerably higher. Increased frequencies of Ki67⁺ NK cells correlated strongly with clinical severity and active nephritis and was also related to low NK cell numbers, but not overall leukopenia. Proteomic and functional data indicate that the cytokine interleukin-15 promotes the induction of Ki67 on NK cells. These results suggest a role for NK cells in regulating the immune-mediated pathology of SLE as well as reveal a possible target for therapeutic intervention.

Rationale and study design of the MyHEART study: A young adult hypertension self-management randomized controlled trial

Young adults (18-39 year-olds) with hypertension have a higher lifetime risk for cardiovascular disease. However, less than 50% of young adults achieve hypertension control in the United States. Hypertension self-management programs are recommended to improve control, but have been targeted to middle-aged and older populations. Young adults need hypertension self-management programs (i.e., home blood pressure monitoring and lifestyle modifications) tailored to their unique needs to lower blood pressure and reduce the risks and medication burden they may face over a lifetime. To address the unmet need in hypertensive care for young adults, we developed MyHEART (My Hypertension Education And Reaching Target), a multi-component, theoretically-based intervention designed to achieve self-management among young adults with uncontrolled hypertension. MyHEART is a patient-centered program, based upon the Self-Determination Theory, that uses evidence-based health behavior approaches to lower blood pressure. Therefore, the objective of this study is to evaluate MyHEART's impact on changes in systolic and diastolic blood pressure compared to usual care after 6 and 12 months in 310 geographically and racially/ethnically diverse young adults with uncontrolled hypertension. Secondary outcomes include MyHEART's impact on behavioral outcomes at 6 and 12 months, compared to usual clinical care (increased physical activity, decreased sodium intake) and to examine whether MyHEART's effects on self-management behavior are mediated through variables of perceived competence, autonomy, motivation, and activation (mediation outcomes). MyHEART is one of the first multicenter, randomized controlled hypertension trials tailored to young adults with primary care. The design and methodology will maximize the generalizability of this study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03158051.

Variation in coordination of care reported by breast cancer patients according to health literacy

BACKGROUND

Health literacy is the ability to perform basic reading and numerical tasks to function in the healthcare environment. The purpose of this study is to describe how health literacy is related to perceived coordination of care reported by breast cancer patients.

METHODS

Data were retrieved from the Patient-Centered Outcomes Research Institute-sponsored "Share Thoughts on Breast Cancer" Study including demographic factors, perceived care coordination and responsiveness of care, and self-reported health literacy obtained from a mailed survey completed by 62% of eligible breast cancer survivors (N = 1221). Multivariable analysis of variance was used to characterize the association between presence of a single healthcare professional that coordinated care ("care coordinator") and perceived care coordination, stratified by health literacy level.

RESULTS

Health literacy was classified as low in 24% of patients, medium in 34%, and high in 42%. Women with high health literacy scores were more likely to report non-Hispanic white race/ethnicity, private insurance, higher education and income, and fewer comorbidities (all p < 0.001). The presence of a care coordinator was associated with 17.1% higher perceived care coordination scores among women with low health literacy when compared to those without a care coordinator, whereas a coordinator modestly improved perceived care coordination among breast cancer survivors with medium (6.9%) and high (6.2%) health literacy.

CONCLUSION

The use of a single designated care coordinator may have a strong influence on care coordination in patients with lower levels of health literacy.

Identification of barriers, facilitators and system-based implementation strategies to increase teleophthalmology use for diabetic eye screening in a rural US primary care clinic: a qualitative study

OBJECTIVE

Teleophthalmology for diabetic eye screening is an evidence-based intervention substantially underused in US multipayer primary care clinics, even when equipment and trained personnel are readily available. We sought to identify patient and primary care provider (PCP) barriers, facilitators, as well as strategies to increase teleophthalmology use.

DESIGN

We conducted standardised open-ended, individual interviews and analysed the transcripts using both inductive and directed content analysis to identify barriers and facilitators to teleophthalmology use. The Chronic Care Model was used as a framework for the development of the interview guide and for categorising implementation strategies to increase teleophthalmology use.

SETTING

A rural, US multipayer primary care clinic with an established teleophthalmology programme for diabetic eye screening.

PARTICIPANTS

We conducted interviews with 29 participants (20 patients with diabetes and 9 PCPs).

RESULTS

Major patient barriers to teleophthalmology use included being unfamiliar with teleophthalmology, misconceptions about diabetic eye screening and logistical challenges. Major patient facilitators included a recommendation from the patient's PCP and factors related to convenience. Major PCP barriers to referring patients for teleophthalmology included difficulty identifying when patients are due for diabetic eye screening and being unfamiliar with teleophthalmology. Major PCP facilitators included the ease of the referral process and the communication of screening results. Based on our results, we developed a model that maps where these key patient and PCP barriers occur in the teleophthalmology referral process. Patients and PCPs also identified implementation strategies to directly address barriers and facilitators to teleophthalmology use.

CONCLUSIONS

Patients and PCPs have limited familiarity with teleophthalmology for diabetic eye screening. PCPs were expected to initiate teleophthalmology referrals, but reported significant difficulty identifying when patients are due for diabetic eye screening. System-based implementation strategies primarily targeting PCP barriers in conjunction with improved patient and provider education may increase teleophthalmology use in rural, US multipayer primary care clinics.

Blood Pressure Control and Other Quality of Care Metrics for Patients with Obesity and Diabetes: A Population-Based Cohort Study

INTRODUCTION

There are no population-level estimates in the United States for achievement of blood pressure goals in patients with diabetes and hypertension by obesity weight class.

AIM

We sought to examine the relationship between the extent of obesity and the achievement of guideline-recommended blood pressure goals and other quality of care metrics among patients with diabetes.

METHODS

We conducted an observational population-based cohort study of electronic health data of three large health systems from 2010-2012 in rural, urban and suburban settings of 51,229 adults with diabetes. Outcomes were achievement of diabetes quality of care metrics: blood pressure, A1c, and LDL control, and A1c and LDL testing. Two blood pressure goals were examined given the recommendation for adults with diabetes of 130/80 mmHg from JNC7 and the recommendation of 140/90 mmHg from JNC8 in 2014.

RESULTS

Patients in obesity classes I, II, and III with diagnosed hypertension were less likely to achieve blood pressure control at both the 140/90 mmHg and 130/80 mmHg control levels. The patients from obesity class III had the lowest likelihood of achieving control at the 130/80 mmHg goal, and control was markedly worse for the 130/80 mmHg threshold in all weight classes. There were minimal to no differences by weight class in LDL and A1c control and LDL and A1c testing.

CONCLUSIONS

Although the cardiovascular risk for patients with obesity and diabetes is greater than for non-obese patients with diabetes, we found that patients with obesity are even further behind in achieving blood pressure control.

Overcoming the dichotomy of implementing societal flood risk management while conserving instream fish habitat - A long-term study from a highly modified urban river

Flood Risk Management (FRM) is often essential to reduce the risk of flooding to properties and infrastructure in urban landscapes, but typically degrades the habitats required by many aquatic animals for foraging, refuge and reproduction. This conflict between flood risk management and biodiversity is driven by conflicting directives, such as the EU Floods and Water Framework Directives, and has led to a requirement for synergistic solutions for FRM that integrate river restoration actions. Unfortunately, ecological monitoring and appraisal of combined FRM and river restoration works is inadequate. This paper uses a case study from the River Don in Northern England to evaluate the effects of the FRM and subsequent river restoration works on instream habitat and the associated fish assemblage over an 8-year period. Flood risk management created a homogeneous channel but did not negatively affect fish species composition or densities, specifically brown trout. Densities of adult brown trout were comparable pre and post-FRM, while densities of juvenile bullhead and brown trout increased dramatically post FRM. River restoration works created a heterogeneous channel but did not significantly improve species composition or brown trout density. Species composition post-river restoration works returned to that similar to pre-FRM over a short-term period, but with improved numbers of juvenile bullhead. Although habitat complexity increased after river restoration works, long-term changes in species composition and densities were marginal, probably because the river reset habitat complexity within the time framework of the study.

Nodes of Ranvier in Glaucoma

Retinal ganglion cell axons of the DBA/2J mouse model of glaucoma, a model characterized by extensive neuroinflammation, preserve synaptic contacts with their subcortical targets for a time after onset of anterograde axonal transport deficits, axon terminal hypertrophy, and cytoskeletal alterations. Though retrograde axonal transport is still evident in these axons, it is unknown if they retain their ability to transmit visual information to the brain. Using a combination of in vivo multiunit electrophysiology, neuronal tract tracing, multichannel immunofluorescence, and transmission electron microscopy, we report that eye-brain signaling deficits precede transport loss and axonal degeneration in the DBA/2J retinal projection. These deficits are accompanied by node of Ranvier pathology - consisting of increased node length and redistribution of the voltage-gated sodium channel Na_v1.6 that parallel changes seen early in multiple sclerosis (MS) axonopathy. Further, with age, axon caliber and neurofilament density increase without corresponding changes in myelin thickness. In contrast to these findings in DBA/2J mice, node pathologies were not observed in the induced microbead occlusion model of glaucoma - a model that lacks pre-existing inflammation. After one week of systemic treatment with fingolimod, an immunosuppressant therapy for relapsing-remitting MS, DBA/2J mice showed a substantial reduction in node pathology and mild effects on axon morphology. These data suggest that neurophysiological deficits in the DBA/2J may be due to defects in intact axons and targeting node pathology may be a promising intervention for some types of glaucoma.

Effectiveness of Outpatient Antibiotics After Surgical Drainage of Abscesses in Reducing Treatment Failure

BACKGROUND

The optimal approach to outpatient antibiotic use after surgical drainage of abscesses is unclear given conflicting clinical trial results.

OBJECTIVE

Our primary objective was to evaluate the real-world effectiveness of outpatient antibiotic prescribing after surgical drainage of cutaneous abscesses on reducing treatment failure.

METHODS

We performed a retrospective observational study using data extracted from the electronic health record of a single academic health care system. All emergency department (ED) visits that resulted in discharge with a surgical drainage of a cutaneous abscess procedure code were included in the sample. All visits were categorized into having received or not having received an antibiotic prescription at the index visit. Outcome frequencies were compared using Pearson's chi-squared test. A multivariable logistic regression model was used to estimate the odds of treatment failure among those who did and did not receive an antibiotic prescription at their index ED visit.

RESULTS

The final sample consisted of 421 index ED visits, of which 303 (72%) received an antibiotic prescription. Treatment with antibiotics after drainage did not significantly reduce the odds of composite treatment failure within 30 days when controlling for sociodemographic and clinical encounter variables (odds ratio 0.52, 95% confidence interval 0.23-1.21).

CONCLUSIONS

This real-world, comparative effectiveness analysis did not demonstrate any significant reduction in treatment failure with the use of antibiotics after drainage of abscesses in the ED. It is unclear if the clinical benefit observed under controlled trial conditions will carry over to routine clinical practice where varied antibiotic regimens are the norm and local bacterial resistance patterns vary.

Primary care colorectal cancer screening correlates with breast cancer screening: implications for colorectal cancer screening improvement interventions

Objective

National colorectal cancer (CRC) screening rates have plateaued. To optimize interventions targeting those unscreened, a better understanding is needed of how this preventive service fits in with multiple preventive and chronic care needs managed by primary care providers (PCPs). This study examines whether PCP practices of other preventive and chronic care needs correlate with CRC screening.

Methods

We performed a retrospective cohort study of 90 PCPs and 33,137 CRC screening-eligible patients. Five PCP quality metrics (breast cancer screening, cervical cancer screening, HgbA1c and LDL testing, and blood pressure control) were measured. A baseline correlation test was performed between these metrics and PCP CRC screening rates. Multivariable logistic regression with clustering at the clinic-level estimated odds ratios and 95% confidence intervals for these PCP quality metrics, patient and PCP characteristics, and their relationship to CRC screening.

Results

PCP CRC screening rates have a strong correlation with breast cancer screening rates (r = 0.7414, p < 0.001) and a weak correlation with the other quality metrics. In the final adjusted model, the only PCP quality metric that significantly predicted CRC screening was breast cancer screening (OR 1.25; 95% CI 1.11–1.42; p < 0.001).

Conclusions

PCP CRC screening rates are highly concordant with breast cancer screening. CRC screening is weakly concordant with cervical cancer screening and chronic disease management metrics. Efforts targeting PCPs to increase CRC screening rates could be bundled with breast cancer screening improvement interventions to increase their impact and success.

Hypertension control after an initial cardiac event among Medicare patients with diabetes mellitus: A multidisciplinary group practice observational study

Patients with diabetes mellitus and cardiovascular disease have a high risk of mortality and/or recurrent cardiovascular events. Hypertension control is critical for secondary prevention of cardiovascular events. The objective was to determine rates and predictors of achieving hypertension control among Medicare patients with diabetes and uncontrolled hypertension after hospital discharge for an initial cardiac event. A retrospective analysis of linked electronic health record and Medicare data was performed. The primary outcome was hypertension control within 1 year after hospital discharge for an initial cardiac event. Cox proportional hazard models assessed sociodemographics, medications, utilization, and comorbidities as predictors of control. Medicare patients with diabetes were more likely to achieve hypertension control when prescribed beta-blockers at discharge or with a history of more specialty visits. Adults ≥ 80 were more likely to achieve control with diuretics. These findings demonstrate the importance of implementing guideline-directed multidisciplinary care in this complex and high-risk population.

Using the Hendrich II Inpatient Fall Risk Screen to Predict Outpatient Falls After Emergency Department Visits

OBJECTIVES

To evaluate the utility of routinely collected Hendrich II fall scores in predicting returns to the emergency department (ED) for falls within 6 months.

DESIGN

Retrospective electronic record review.

SETTING

Academic medical center ED.

PARTICIPANTS

Individuals aged 65 and older seen in the ED from January 1, 2013, through September 30, 2015.

MEASUREMENTS

We evaluated the utility of routinely collected Hendrich II fall risk scores in predicting ED visits for a fall within 6 months of an all-cause index ED visit.

RESULTS

For in-network patient visits resulting in discharge with a completed Hendrich II score (N = 4,366), the return rate for a fall within 6 months was 8.3%. When applying the score alone to predict revisit for falls among the study population the resultant receiver operating characteristic (ROC) plot had an area under the curve (AUC) of 0.64. In a univariate model, the odds of returning to the ED for a fall in 6 months were 1.23 times as high for every 1-point increase in Hendrich II score (odds ratio (OR)=1.23 (95% confidence interval (CI)=1.19-1.28). When included in a model with other potential confounders or predictors of falls, the Hendrich II score is a significant predictor of a return ED visit for fall (adjusted OR=1.15, 95% CI=1.10-1.20, AUC=0.75).

CONCLUSION

Routinely collected Hendrich II scores were correlated with outpatient falls, but it is likely that they would have little utility as a stand-alone fall risk screen. When combined with easily extractable covariates, the screen performs much better. These results highlight the potential for secondary use of electronic health record data for risk stratification of individuals in the ED. Using data already routinely collected, individuals at high risk of falls after discharge could be identified for referral without requiring additional screening resources.

Autologous Blood Transfusion in Elective Orthopaedic Surgery

Autologous blood transfusion is one of the most effective ways of avoiding the need for homologous transfusion and all its associated complications. Since the beginning of 1985, autotransfusions have been used in 48 patients undergoing total joint replacement, without significant complications. Their average haemoglobin level two weeks postoperatively was 11.3 mg/dl. We believe that this is a safe, effective and economical procedure which benefits both patients and medical staff, and its use should be more widespread.

Enhanced Phosphorylation of Bax and Its Translocation into Mitochondria in the Brains of Individuals Affiliated with Alzheimer's Disease

Background:

Despite increased neuronal death, senile plaques, and neurofibrillary tangles observed in patients suffering from Alzheimer’s disease (AD), the detailed mechanism of cell death in AD is still poorly understood.

Method:

We hypothesized that p38 kinase activates and then phosphorylates Bax, leading to its translocation to mitochondria in AD brains compared to controls. The aim of this study was to investigate the role of p38 kinase in phosphorylation and sub-cellular localization of pro-apoptotic Bax in the frontal cortex of the brains from AD and control subjects. Increased oxidative stress in AD individuals compared to control was evaluated by measuring the levels of carbonylated proteins and oxidized peroxiredoxin, an antioxidant enzyme. The relative amounts of p38 kinase and phospho-Bax in mitochondria in AD brains and controls were determined by immunoblot analysis using the respective antibody against each protein following immunoprecipitation.

Results:

Our results showed that the levels of oxidized peroxiredoxin-SO₃ and carbonylated proteins are significantly elevated in AD brains compared to controls, demonstrating the increased oxidative stress.

Conclusion:

The amount of phospho-p38 kinase is increased in AD brains and the activated p38 kinase appears to phosphorylate Thr residue(s) of Bax, which leads to its mitochondrial translocation, contributing to apoptosis and ultimately, neurodegeneration.

Thirty-day readmission and mortality among Medicare beneficiaries discharged to skilled nursing facilities after vascular surgery

BACKGROUND

Readmission within 30 d of an acute hospital stay is frequent, costly, and increasingly subject to penalties. Early readmission is most common after vascular surgery; these patients are often discharged to skilled nursing facilities (SNFs), making postacute care an essential partner in reducing readmissions. We characterize 30-day readmissions among vascular surgery patients discharged to SNF to provide evidence for this understudied segment of readmission after specialty surgery.

METHODS

We utilize the Centers for Medicare & Medicaid Services Chronic Conditions Warehouse, a longitudinal 5% national random sample of Medicare beneficiaries to study 30-day readmission or death after discharge to SNF following abdominal aortic aneurysm repair or lower extremity revascularization from 2005-2009. Descriptive statistics and logistic regression with Least Adaptive Shrinkage and Selection Operator were used for analysis.

RESULTS

Two thousand one hundred ninety-seven patients underwent an abdominal aortic aneurysm procedure or lower extremity revascularization at 686 hospitals and discharged to 1714 SNFs. Eight hundred (36%) were readmitted or had died at 30 d. In adjusted analysis, predictors of readmission or death at 30 d included SNF for-profit status (OR [odds ratio] = 1.2; P = 0.032), number of hospitalizations in the previous year (OR = 1.06; P = 0.011), number of comorbidities (OR = 1.06; P = 0.004), emergent procedure (OR = 1.69; P < 0.001), renal complication (OR = 1.38; P = 0.003), respiratory complication (OR = 1.45; P < 0.001), thromboembolic complication (OR = 1.57; P = 0.019), and wound complication (OR = 0.70; P = 0.017).

CONCLUSIONS

Patients discharged to SNF following vascular surgery have exceptionally high rates of readmission or death at 30 d. Many factors predicting readmission or death potentially modify decision-making around discharge, making early detection, discharge planning, and matching patient needs to SNF capabilities essential to improving outcomes.

The importance of frequent return visits and hypertension control among US young adults: a multidisciplinary group practice observational study

Young adults (aged 18 to 39 years) have the lowest hypertension control rates compared with older adults. Shorter follow-up encounter intervals are associated with faster hypertension control rates in older adults; however, optimal intervals are unknown for young adults. The study objective was to evaluate the relationship between ambulatory blood pressure encounter intervals (average number of provider visits with blood pressures over time) and hypertension control rates among young adults with incident hypertension. A retrospective analysis was conducted of patients aged 18 to 39 years (n = 2990) with incident hypertension using Kaplan-Meier survival and Cox proportional hazards analyses over 24 months. Shorter encounter intervals were associated with higher hypertension control: <1 month (91%), 1 to 2 months (76%), 2 to 3 months (65%), 3 to 6 months (40%), and >6 months (13%). Young adults with shorter encounter intervals also had lower medication initiation, supporting the effectiveness of lifestyle modifications. Sustainable interventions for timely young adult follow-up are essential to improve hypertension control in this hard-to-reach population.

Insurance Coverage for CT Colonography Screening: Impact on Overall Colorectal Cancer Screening Rates

RSNA, 2017.

Using Chief Complaint in Addition to Diagnosis Codes to Identify Falls in the Emergency Department

OBJECTIVES

To compare incidence of falls in an emergency department (ED) cohort using a traditional International Classification of Diseases, Ninth Revision (ICD-9) code-based scheme and an expanded definition that included chief complaint information and to examine the clinical characteristics of visits "missed" in the ICD-9-based scheme.

DESIGN

Retrospective electronic record review.

SETTING

Academic medical center ED.

PARTICIPANTS

Individuals aged 65 and older seen in the ED between January 1, 2013, and September 30, 2015.

MEASUREMENTS

Two fall definitions were applied (individually and together) to the cohort: an ICD-9-based definition and a chief complaint definition. Admission rates and 30-day mortality (per encounter) were measured for each definition.

RESULTS

Twenty-three thousand eight hundred eighty older adult visits occurred during the study period. Using the most-inclusive definition (ICD-9 code or chief complaint indicating a fall), 4,363 visits (18%) were fall related. Of these visits, 3,506 (80%) met the ICD-9 definition for a fall-related visit, and 2,664 (61%) met the chief complaint definition. Of visits meeting the chief complaint definition, 857 (19.6%) were missed when applying the ICD-9 definition alone. Encounters missed using the ICD-9 definition were less likely to lead to an admission (42.9%, 95% confidence interval (CI) = 39.7-46.3%) than those identified (54.4%, 95% CI = 52.7-56.0%).

CONCLUSION

Identifying individuals in the ED who have fallen based on diagnosis codes underestimates the true burden of falls. Individuals missed according to the code-based definition were less likely to have been admitted than those who were captured. These findings call attention to the value of using chief complaint information to identify individuals who have fallen in the ED-for research, clinical care, or policy reasons.

Utilization of preoperative endoscopic ultrasound for pancreatic adenocarcinoma

BACKGROUND

Endoscopic ultrasound (EUS) is used for pancreatic adenocarcinoma staging and obtaining a tissue diagnosis. The objective was to determine patterns of preoperative EUS and the impact on downstream treatment.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Medicare-linked database was used to identify patients with pancreatic adenocarcinoma. The staging period was the first staging procedure within 6 months of surgery until surgery. Logistic regression was used to determine factors associated with preoperative EUS. The main outcome was EUS in the staging period, with secondary outcomes including number of staging tests and time to surgery.

RESULTS

2782 patients were included, 56% were treated at an academic hospital (n = 1563). 1204 patients underwent EUS (43.3%). The factors most associated with receipt of EUS were: earlier year of diagnosis, SEER area, and a NCI or academic hospital (all p < 0.0001). EUS was associated with a longer time to surgery (17.8 days; p < 0.0001), and a higher number of staging tests (40 tests/100 patients; p < 0.0001).

CONCLUSIONS

Factors most associated with receipt of EUS are geographic, temporal, and institutional, rather than clinical/disease factors. EUS is associated with a longer time to surgery and more preoperative testing, and additional study is needed to determine if EUS is overused.

Predictors of primary care provider adoption of CT colonography for colorectal cancer screening

PURPOSE

To examine factors influencing primary care provider (PCP) adoption of CT colonography (CTC) for colorectal cancer (CRC) screening.

MATERIALS AND METHODS

We performed a retrospective cohort study linking electronic health record (EHR) data with PCP survey data. Patients were eligible for inclusion if they were not up-to-date with CRC screening and if they had CTC insurance coverage in the year prior to survey administration. PCPs were included if they had at least one eligible patient in their panel and completed the survey (final sample N = 95 PCPs; N = 6245 patients). Survey data included perceptions of CRC screening by any method, as well as CTC specifically. Multivariate logistic regression estimated odds ratios and 95% confidence intervals for PCP and clinic predictors of CRC screening by any method and screening with CTC.

RESULTS

Substantial variation in CTC use was seen among PCPs and clinics (range 0-16% of CRC screening). Predictors of higher CTC use were PCP perceptions that CTC is effective in reducing CRC mortality, higher number of perceived advantages to screening with CTC, and Internal Medicine specialty. Factors not associated with CTC use were PCP perceptions of less organizational capacity to meet demand for colonoscopy, number of perceived disadvantages to screening with CTC, PCP age and gender, and clinic factors.

CONCLUSION

Significant variation in PCP adoption of CTC exists. PCP perceptions of CTC and specialty practice were related to CTC adoption. Strategies to increase PCP adoption of CTC for CRC screening should include emphasis on the effectiveness and advantages of CTC.

Monkey prefrontal neurons during Sternberg task performance: full contents of working memory or most recent item?

To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate.NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or represented within the prefrontal cortex in a cryptic code.

Abstract 185: The Relationship of Ambulatory Visit Frequency and Hypertension Control Among Young Adults

Background: Young adults (18-39 years old) have the lowest rates of hypertension control compared to middle-aged and older adults. Shorter follow-up encounter intervals have been associated with faster rates of hypertension control in middle-aged and older adults. However, the optimal follow-up interval is not defined in younger adults. The objective was to evaluate the relationship between ambulatory follow-up intervals, defined as the average number of provider-patient blood pressure encounters over time, and rates of hypertension control among young adults with incident hypertension.

Methods: This was a retrospective analysis of 3,150 young adults receiving regular primary care in a large, Midwestern, academic group practice from 2008-2011. Patients were included upon meeting JNC7 clinical criteria for hypertension (≥140/90 mmHg) and followed for 24 months. Young adults with a previous hypertension diagnosis or prior antihypertensive medication were excluded. We calculated the average blood pressure encounter interval over 24 months and categorized the intervals using established categories of <1 month, 1-2 months, 2-3 months, 3-6 months, and >6 month intervals. Summary statistics were constructed using frequencies and proportions for categorical data and median (25 th , 75 th percentile) for continuous variables. Univariate associations between continuous variables were assessed using two-sided t-test. The probability of achieving hypertension control (<140/90 mmHg) for patients within each encounter interval category was estimated by Kaplan-Meier analysis.

Results: Among young adults with newly diagnosed hypertension (59% male, 83% White), those with the shortest average encounter interval (<1 month) were more likely to be female, have Stage 1 (mild) hypertension, Medicaid use, diabetes mellitus, and mental health diagnoses (all p<0.007). The likelihood of achieving hypertension control within 24 months was greater for shorter encounter intervals: <1 month (91%), 1-2 months (76%), 2-3 months (65%), 3-6 months (40%), and >6 months (13%), p<0.001. Respectively, the median time in months to hypertension control (25 th -75 th percentile) by encounter intervals was: 2.8 (1.8-3.9), 7.1 (5.1-11.3), 10.5 (8.5-14.4), 16.4 (12.4-22.6), and 23.9 (22.5-24.1) months. Young adults with 2-3 month and 3-6 month encounter intervals had higher rates of antihypertensive medication initiation within 24 months, 28% (884/3150) and 27% (850/3150) respectively, compared to 21% (661/3150) with <1 month visit interval.

Conclusions: A shorter encounter interval (<1 month) is associated with higher and faster rates of hypertension control within 24 months among young adults with incident hypertension. Sustainable interventions to support shorter follow-up intervals between young adults and primary care teams are needed to improve rates and timeliness of hypertension control.

Mapping in-vivo optic nerve head strains caused by intraocular and intracranial pressures

Although it is well documented that abnormal levels of either intraocular (IOP) or intracranial pressure (ICP) can lead to potentially blinding conditions, such as glaucoma and papilledema, little is known about how the pressures actually affect the eye. Even less is known about potential interplay between their effects, namely how the level of one pressure might alter the effects of the other. Our goal was to measure in-vivo the pressure-induced stretch and compression of the lamina cribrosa due to acute changes of IOP and ICP. The lamina cribrosa is a structure within the optic nerve head, in the back of the eye. It is important because it is in the lamina cribrosa that the pressure-induced deformations are believed to initiate damage to neural tissues leading to blindness. An eye of a rhesus macaque monkey was imaged in-vivo with optical coherence tomography while IOP and ICP were controlled through cannulas in the anterior chamber and lateral ventricle, respectively. The image volumes were analyzed with a newly developed digital image correlation technique. The effects of both pressures were highly localized, nonlinear and non-monotonic, with strong interactions. Pressure variations from the baseline normal levels caused substantial stretch and compression of the neural tissues in the posterior pole, sometimes exceeding 20%. Chronic exposure to such high levels of biomechanical insult would likely lead to neural tissue damage and loss of vision. Our results demonstrate the power of digital image correlation technique based on non-invasive imaging technologies to help understand how pressures induce biomechanical insults and lead to vision problems.

The Association Between Geographic Density of Infectious Disease Physicians and Limb Preservation in Patients With Diabetic Foot Ulcers

Background

Avoiding major (above-ankle) amputation in patients with diabetic foot ulcers is best accomplished by multidisciplinary care teams with access to infectious disease specialists. However, access to infectious disease physicians is partially influenced by geography. We assessed the effect of living in a hospital referral region with a high geographic density of infectious disease physicians on major amputation for patients with diabetic foot ulcers. We studied geographic density, rather than infectious disease consultation, to capture both the direct and indirect (eg, informal consultation) effects of access to these providers on major amputation.

Methods

We used a national retrospective cohort of 56440 Medicare enrollees with incident diabetic foot ulcers. Cox proportional hazard models were used to assess the relationship between infectious disease physician density and major amputation, while controlling for patient demographics, comorbidities, and ulcer severity.

Results

Living in hospital referral regions with high geographic density of infectious disease physicians was associated with a reduced risk of major amputation after controlling for demographics, comorbidities, and ulcer severity (hazard ratio, .83; 95% confidence interval, .75–.91; P < .001). The relationship between the geographic density of infectious disease physicians and major amputation was not different based on ulcer severity and was maintained when adjusting for socioeconomic factors and modeling amputation-free survival.

Conclusions

Infectious disease physicians may play an important role in limb salvage. Future studies should explore whether improved access to infectious disease physicians results in fewer major amputations.

Endovascular Versus Open Revascularization for Peripheral Arterial Disease

OBJECTIVE

The aim of this study was to determine whether endovascular or open revascularization provides an advantageous approach to symptomatic peripheral arterial disease (PAD) over the longer term.

SUMMARY OF BACKGROUND DATA

The optimal revascularization strategy for symptomatic lower extremity PAD is not established.

METHODS

We evaluated amputation-free survival, overall survival, and relative rate of subsequent vascular intervention after endovascular or open lower extremity revascularization for propensity-score matched cohorts of Medicare beneficiaries with PAD from 2006 through 2009.

RESULTS

Among 14,685 eligible patients, 5928 endovascular and 5928 open revascularization patients were included in matched analysis. Patients undergoing endovascular repair had improved amputation-free survival compared with open repair at 30 days (7.4 vs 8.9%, P = 0.002). This benefit persisted over the long term: At 4 years, 49% of endovascular patients had died or received major amputation compared with 54% of open patients (P < 0.001). An endovascular procedure was associated with a risk-adjusted 16% decreased risk of amputation or death compared with open over the study period (hazard ratio: 0.84; 95% confidence interval, 0.79-0.89; P < 0.001). The amputation-free survival benefit associated with an endovascular revascularization was more pronounced in patients with congestive heart failure or ischemic heart disease than in those without (P = 0.021 for interaction term). The rate of subsequent intervention at 30 days was 7.4% greater for the endovascular vs the open revascularization cohort. At 4 years, this difference remained stable at 8.6%.

CONCLUSIONS

Using population-based data, we demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

Correlation between Cerebral Hemodynamic and Perfusion Pressure Changes in Non-Human Primates

The mechanism that maintains a stable blood flow in the brain despite changes in cerebral perfusion pressure (CPP), and therefore guaranties a constant supply of oxygen and nutrients to the neurons, is known as cerebral autoregulation (CA). In a certain range of CPP, blood flow is mediated by a vasomotor adjustment in vascular resistance through dilation of blood vessels. CA is known to be impaired in diseases like traumatic brain injury, Parkinson's disease, stroke, hydrocephalus and others. If CA is impaired, blood flow and pressure changes are coupled and the oxygen supply might be unstable. Lassen's blood flow autoregulation curve describes this mechanism, where a plateau of stable blood flow in a specific range of CPP corresponds to intact autoregulation. Knowing the limits of this plateau and maintaining CPP within these limits can improve patient outcome. Since CPP is influenced by both intracranial pressure and arterial blood pressure, long term changes in either can lead to autoregulation impairment. Non-invasive methods for monitoring blood flow autoregulation are therefore needed. We propose to use Near infrared spectroscopy (NIRS) to fill this need. NIRS is an optical technique, which measures microvascular changes in cerebral hemoglobin concentration. We pe erformed experiments on non-human primates during exsanguination to demonstrate that the limits of blood flow autoregulation can be accessed with NIRS.

Multidimensional Model of Racial Identity: A Reconceptualization of African American Racial Identity

Research on African American racial identity has utilized 2 distinct approaches. The mainstream approach has focused on universal properties associated with ethnic and racial identities. In contrast, the underground approach has focused on documenting the qualitative meaning of being African American, with an emphasis on the unique cultural and historical experiences of African Americans. The Multidimensional Model of Racial Identity (MMRI) represents a synthesis of the strengths of these two approaches. The underlying assumptions associated with the model are explored. The model proposes 4 dimensions of African American racial identity: salience, centrality, regard, and ideology. A description of these dimensions is provided along with a discussion of how they interact to influence behavior at the level of the event. We argue that the MMRI has the potential to make contributions to traditional research objectives of both approaches, as well as to provide the impetus to explore new questions.