Development of an ultrasound-based metric of muscle functional capacity for use in patients with neuromuscular disease.

INTRODUCTION/AIMS: Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are progressive neuromuscular disorders characterized by severe muscle weakness and functional decline (Pillen et al., Muscle Nerve 2008; 37(6):679-693). With new therapeutics, objective methods with increased sensitivity are needed to assess muscle function. Ultrasound imaging is a promising approach for assessing muscle fat and fibrosis in neuromuscular disorders. This study builds on prior work by combining ultrasound-based measurements of muscle size, shape, and quality, relating these measures to muscle strength, and proposing a multivariable image-based estimate of muscle function. METHODS: Maximum voluntary elbow flexion torque of 36 participants (SMA, DMD, and healthy controls) was measured by hand-held dynamometry and elbow flexor muscles were imaged using ultrasound. Muscle size (cross-sectional area, maximum Feret diameter or width, and thickness), quality (echogenicity, texture anisotropy index), and cross-sectional shape (diameter ratio) were measured. Multivariable regression was used to select ultrasound measurements that predict elbow flexion torque. RESULTS: Significant differences were observed in muscle size (decreased), shape (thinned), and quality (decreased) with increased disease severity and compared to healthy participants. CSA (brachioradialis R2 = 0.51), maximum Feret diameter (biceps R2 = 0.49, brachioradialis R2 = 0.58) and echogenicity (brachioradialis R2 = 0.61) were most correlated with torque production. Multivariable regression models identified that muscle size (CSA, maximum Feret diameter) and quality (echogenicity) were both essential to predict elbow flexion torque (R2 = 0.65). DISCUSSION: A multivariable approach combining muscle size and quality improves strength predictions over single variable approaches. These methods present a promising avenue for the development of sensitive and functionally relevant biomarkers of neuromuscular disease.

The impact of post-mastectomy radiation timing on overall outcomes of autologous free-flap breast reconstruction.

BACKGROUND: The optimal timing of post-mastectomy radiation therapy (PMRT) in autologous breast reconstruction is controversial. Our study compares overall reconstructive outcomes in patients who received post-mastectomy radiation therapy either before or after the autologous flap. METHODS: A single-center retrospective review was performed for patients who underwent free flap breast reconstruction and post-mastectomy radiation from January 2004 through January 2021. Demographic, intraoperative, and post-operative variables were recorded. RESULTS: A total of 452 free flaps were identified, and 82 underwent PMRT. 59.8% were radiated with an expander prior to free flap surgery (PreFlap), and 40.2% flaps underwent PMRT (PostFlap). PostFlap patients were significantly younger (43.0 vs. 47.9 years, p = .016). There were no significant differences in free flap outcomes between the two cohorts including thrombosis, venous congestion, flap loss, takebacks, fat necrosis, seroma, or infection. Mastectomy skin flap necrosis was significantly higher in the PostFlap cohort (9.1% vs. 0%, p = .032), but nipple necrosis rates did not differ. There were no significant differences in number or need for revision surgeries, fat necrosis, or fat grafting between groups. However, there were significantly more total reconstructive complications, including infection and wound breakdown, experienced by the PreFlap cohort (46.9% vs. 24.2%, p = .038). CONCLUSIONS: Timing of PMRT did not impact free flap outcomes, but those who had the expander radiated experienced significantly more complications overall. For the 34.7% of patients in the preFlap group who planned for autologous reconstruction form initial consultation, radiation after the flap may have improved their overall outcomes. As added complications cause delays in cancer therapy and final reconstruction, our results suggest that PMRT of the flap when possible may improve the overall experience for breast cancer patients.

Nipple-Sparing Mastectomies in Patients over the Age of 60 Years: Factors Associated with Surgical Outcomes.

BACKGROUND: Nipple-sparing mastectomy (NSM) outcomes in the elderly have not been well characterized. The goal of this study was to evaluate NSM outcomes in patients over age 60. PATIENTS AND METHODS: A single-institution retrospective cohort study was performed for NSM patients over the age of 60 from January 2004 to January 2022. Demographic, intraoperative, and postoperative variables were collected. RESULTS: We identified 136 women who underwent a total of 200 NSMs at a mean age 65.2 years and with mean body mass index of 25. Most (56%) had invasive breast cancer, requiring neoadjuvant chemotherapy in 15%, and 17.5% had radiation prior to NSM. A total of 91% had immediate tissue expander placement. The infection rate was 19%, with 11.5% requiring expander explantation in the follow-up period. In binomial logistic regression analysis, prior radiation increased the odds of any complication by 2.9 (OR 2.93, CI 1.30-6.58, p = 0.009) and increased the odds of infection by 5.7 (OR 5.70, CI 1.95-16.66, p = 0.001), but no associations were seen for other covariates including age, comorbidities, prior chemotherapy, or presence of invasive disease. Diabetes increased the odds of wound breakdown specifically by 9.0 (OR 8.97, CI 2.01-39.92, p = 0.004). Local recurrence was 3% in mean 3.4-year follow-up. CONCLUSIONS: Our data support NSM in patients over the age of 60 years with acceptable outcomes within the standard of care. Locoregional recurrence was within the cited range of 0-5%, and only diabetes and prior radiation were associated with reconstructive complications. NSM should thus be offered when appropriate regardless of increased age to achieve oncologic and reconstructive goals.

Scene-dependent, feedforward eye gaze metrics can differentiate technical skill levels of trainees in laparoscopic surgery.

INTRODUCTION: In laparoscopic surgery, looking in the target areas is an indicator of proficiency. However, gaze behaviors revealing feedforward control (i.e., looking ahead) and their importance have been under-investigated in surgery. This study aims to establish the sensitivity and relative importance of different scene-dependent gaze and motion metrics for estimating trainee proficiency levels in surgical skills. METHODS: Medical students performed the Fundamentals of Laparoscopic Surgery peg transfer task while recording their gaze on the monitor and tool activities inside the trainer box. Using computer vision and fixation algorithms, five scene-dependent gaze metrics and one tool speed metric were computed for 499 practice trials. Cluster analysis on the six metrics was used to group the trials into different clusters/proficiency levels, and ANOVAs were conducted to test differences between proficiency levels. A Random Forest model was trained to study metric importance at predicting proficiency levels. RESULTS: Three clusters were identified, corresponding to three proficiency levels. The correspondence between the clusters and proficiency levels was confirmed by differences between completion times (F2,488 = 38.94, p < .001). Further, ANOVAs revealed significant differences between the three levels for all six metrics. The Random Forest model predicted proficiency level with 99% out-of-bag accuracy and revealed that scene-dependent gaze metrics reflecting feedforward behaviors were more important for prediction than the ones reflecting feedback behaviors. CONCLUSION: Scene-dependent gaze metrics revealed skill levels of trainees more precisely than between experts and novices as suggested in the literature. Further, feedforward gaze metrics appeared to be more important than feedback ones at predicting proficiency.

Immediate Versus Delayed-Immediate Autologous Breast Reconstruction After Nipple-Sparing Mastectomy.

INTRODUCTION: Autologous reconstruction following nipple-sparing mastectomy (NSM) is either performed in a delayed-immediate fashion, with a tissue expander placed initially at the time of mastectomy and autologous reconstruction performed later, or immediately at the time of NSM. It has not been determined which method of reconstruction leads to more favorable patient outcomes and lower complication rates. METHODS: We performed a retrospective chart review of all patients who underwent autologous abdomen-based free flap breast reconstruction after NSM between January 2004 and September 2021. Patients were stratified into 2 groups by timing of reconstruction (immediate and delayed-immediate). All surgical complications were analyzed. RESULTS: One hundred one patients (151 breasts) underwent NSM followed by autologous abdomen-based free flap breast reconstruction during the defined time period. Fifty-nine patients (89 breasts) underwent immediate reconstruction, whereas 42 patients (62 breasts) underwent delayed-immediate reconstruction. Considering only the autologous stage of reconstruction in both groups, the immediate reconstruction group experienced significantly more delayed wound healing, wounds requiring reoperation, mastectomy skin flap necrosis, and nipple-areolar complex necrosis. Analysis of cumulative complications from all reconstructive surgeries revealed that the immediate reconstruction group still experienced significantly greater cumulative rates of mastectomy skin flap necrosis. However, the delayed-immediate reconstruction group experienced significantly greater cumulative rates of readmission, any infection, infection requiring PO antibiotics, and infection requiring IV antibiotics. CONCLUSIONS: Immediate autologous breast reconstruction after NSM alleviates many issues seen with tissue expanders and delayed autologous reconstruction. Although mastectomy skin flap necrosis occurs at a significantly greater rate after immediate autologous reconstruction, it can often be managed conservatively.

Evaluation of Microvascular Autologous Breast Reconstruction in Patients Older Than 60 Years.

BACKGROUND: While free-flap breast reconstruction becomes more common, it is still approached with caution in older patients. Outcomes in the elderly population have not been well characterized, especially with regard to donor-site sequalae. This study compares microvascular autologous breast reconstruction outcomes in patients older and younger 60 years. METHODS: A single-institution retrospective review was performed for microvascular autologous breast reconstruction from January 2004 through January 2021. Demographic, intraoperative, and postoperative variables, including breast flap and donor-site complications, were evaluated. RESULTS: Five hundred forty-five breast free flaps were identified, of which 478 (87.8%) were performed on patients younger than 60 years (mean, 46.2 years) and 67 (12.2%) older than 60 years (mean, 64.8 years; P = 0.000). Hyperlipidemia was significantly higher in older patients (19.4% vs 9.6%, P = 0.016). Mean operative time was 46.3 minutes faster in the older cohort ( P = 0.030). There were no significant differences in free-flap loss, venous congestion, takeback, hematoma, seroma, wound healing, or infection. Interestingly, there were significantly more total breast flap complications (28.5% vs 16.4%, P = 0.038) and higher rates of fat necrosis (9.6% vs 1.5%, P = 0.026) in the younger cohort. Significantly more abdominal donor-site complications (43.3% vs 21.3%, P = 0.000) were seen in the older people, with increased wound breakdown ( P = 0.000) and any return to the operating room (20.9% vs 9.8%, P = 0.007). Older patients were also significantly more likely to require surgical correction of an abdominal bulge or hernia (10.4% vs 4%, P = 0.020). The mean follow-up was 1.8 years. CONCLUSIONS: Our data showed no worsening of individual breast flap outcomes in the older people. However, there were significantly more abdominal complications including surgical correction of abdominal bulge and hernia. This may be related to the inherent qualities of tissue aging and should be taken into consideration for flap selection. These results support autologous breast reconstruction in patients older than 60 years, but patients should be counseled regarding potentially increased abdominal donor-site sequelae.

Gender-Affirming Facial Feminization Surgery at a Public, Safety-Net Hospital: A Single-Center Early Experience.

BACKGROUND: Facial feminization surgery (FFS) remains inaccessible to many transgender patients. Zuckerberg San Francisco General Hospital (ZSFG) was among the first public, safety-net hospitals to perform FFS. The purpose of this study is to examine the postoperative outcomes of patients who underwent FFS at ZSFG and describe barriers to providing FFS in a public hospital setting. METHODS: A retrospective review identified patients who underwent FFS at ZSFG. Demographic data, comorbidity profiles, postoperative outcomes, and hospital utilization data were collected from the medical records. FACE-Q modules (scored 0-100) were used to survey patient satisfaction at least 1 year postoperatively. RESULTS: Seventeen patients underwent comprehensive FFS surgery at ZSFG. The median age was 41 years [interquartile range (IQR): 38-55], median body mass index was 26.4 (IQR: 24.1-31.3). Patients underwent a median of 9 procedures, the most common of which included frontal cranioplasty (n=13, 77%), open brow lift (n=13, 77%), rhinoplasty (n=12, 71%), and mandible contouring (n=12, 71%). There were no complications, readmissions, or reoperations within 30 days. Patients reported high satisfaction with the surgical outcome (median: 87, IQR: 87-100), excellent postoperative psychological functioning (median: 100, IQR: 88-100), and low levels of appearance-related distress (median: 3, IQR: 0-35). An estimated 243 operating room hours and 51 inpatient bed days were required to cover all FFS procedures. CONCLUSIONS: Performing FFS in a public, safety-net hospital was associated with zero postoperative complications, few revision procedures, and excellent patient satisfaction. Limited operating room hours and inpatient availability represented barriers to providing FFS in this setting.

Minimal Effect of Messaging on Engagement in a Digital Anxiety Intervention.

This study evaluated the effectiveness of different recruitment messages for encouraging enrollment in a digital mental health intervention (DMHI) for anxiety among 1,600 anxious patients in a large healthcare system. Patients were randomly assigned to receive a standard message, or one of five messages designed to encourage enrollment: Three messages offered varying financial incentives, one message offered coaching, and one message provided consumer testimonials. Patients could then click a link in the message to visit the DMHI website, enroll, and start the first session. We examined the effects of message features and message length (short vs. long) on rates of site clicks, enrollment, and starting the first session. We also tested whether demographic and clinical factors derived from patients' electronic health records were associated with rates of enrollment and starting the first session to understand the characteristics of patients most likely to use DMHIs in this setting. Across messages, 19.4% of patients clicked a link to visit the DMHI website, but none of the messages were significantly associated with rates of site clicks, enrollment, or starting the first session. Females (vs. males) had a greater probability of enrollment. No other demographic or clinical variables were significantly associated with enrollment or starting the first session. Findings provide guidance for resource allocation decisions in larger scale DMHI implementations in healthcare settings.

NAPS Fusion: A framework to overcome experimental data limitations to predict human performance and cognitive task outcomes.

In the area of human performance and cognitive research, machine learning (ML) problems become increasingly complex due to limitations in the experimental design, resulting in the development of poor predictive models. More specifically, experimental study designs produce very few data instances, have large class imbalances and conflicting ground truth labels, and generate wide data sets due to the diverse amount of sensors. From an ML perspective these problems are further exacerbated in anomaly detection cases where class imbalances occur and there are almost always more features than samples. Typically, dimensionality reduction methods (e.g., PCA, autoencoders) are utilized to handle these issues from wide data sets. However, these dimensionality reduction methods do not always map to a lower dimensional space appropriately, and they capture noise or irrelevant information. In addition, when new sensor modalities are incorporated, the entire ML paradigm has to be remodeled because of new dependencies introduced by the new information. Remodeling these ML paradigms is time-consuming and costly due to lack of modularity in the paradigm design, which is not ideal. Furthermore, human performance research experiments, at times, creates ambiguous class labels because the ground truth data cannot be agreed upon by subject-matter experts annotations, making ML paradigm nearly impossible to model. This work pulls insights from Dempster-Shafer theory (DST), stacking of ML models, and bagging to address uncertainty and ignorance for multi-classification ML problems caused by ambiguous ground truth, low samples, subject-to-subject variability, class imbalances, and wide data sets. Based on these insights, we propose a probabilistic model fusion approach, Naive Adaptive Probabilistic Sensor (NAPS), which combines ML paradigms built around bagging algorithms to overcome these experimental data concerns while maintaining a modular design for future sensor (new feature integration) and conflicting ground truth data. We demonstrate significant overall performance improvements using NAPS (an accuracy of 95.29%) in detecting human task errors (a four class problem) caused by impaired cognitive states and a negligible drop in performance with the case of ambiguous ground truth labels (an accuracy of 93.93%), when compared to other methodologies (an accuracy of 64.91%). This work potentially sets the foundation for other human-centric modeling systems that rely on human state prediction modeling.

Building an emotion regulation recommender algorithm for socially anxious individuals using contextual bandits.

OBJECTIVES: Poor emotion regulation (ER) has been implicated in many mental illnesses, including social anxiety disorder. To work towards a scalable, low-cost intervention for improving ER, we developed a novel contextual recommender algorithm for ER strategies. DESIGN: N = 114 socially anxious participants were prompted via a mobile app up to six times daily for five weeks to report their emotional state, use of 19 different ER strategies (or no strategy), physical location, and social context. Information from passive sensors was also collected. METHODS: Given the large number of ER strategies, we used two different approaches for variable reduction: (1) grouping ER strategies into categories based on a prior meta-analysis, and (2) considering only the ten most frequently used strategies. For each approach, an algorithm that recommends strategies based on one's current context was compared with an algorithm that recommends ER strategies randomly, an algorithm that always recommends cognitive reappraisal, and the person's observed ER strategy use. Contextual bandits were used to predict the effectiveness of the strategies recommended by each policy. RESULTS: When strategies were grouped into categories, the contextual algorithm was not the best performing policy. However, when the top ten strategies were considered individually, the contextual algorithm outperformed all other policies. CONCLUSIONS: Grouping strategies into categories may obscure differences in their contextual effectiveness. Further, using strategies tailored to context is more effective than using cognitive reappraisal indiscriminately across all contexts. Future directions include deploying the contextual recommender algorithm as part of a just-in-time intervention to assess real-world efficacy. PRACTITIONER POINTS: Emotion regulation strategies vary in their effectiveness across different contexts. An algorithm that recommends emotion regulation strategies based on a person's current context may one day be used as an adjunct to treatment to help dysregulated individuals optimize their in-the-moment emotion regulation. Recommending flexible use of emotion regulation strategies across different contexts may be more effective than recommending cognitive reappraisal indiscriminately across all contexts.

Evaluation of a Virtual Training to Enhance Public Health Capacity for COVID-19 Infection Prevention and Control in Nursing Homes.

CONTEXT: Between April 2020 and May 2021, the Centers for Disease Control and Prevention (CDC) awarded more than $40 billion to health departments nationwide for COVID-19 prevention and response activities. One of the identified priorities for this investment was improving infection prevention and control (IPC) in nursing homes. PROGRAM: CDC developed a virtual course to train new and less experienced public health staff in core healthcare IPC principles and in the application of CDC COVID-19 healthcare IPC guidance for nursing homes. IMPLEMENTATION: From October 2020 to August 2021, the CDC led training sessions for 12 cohorts of public health staff using pretraining reading materials, case-based scenarios, didactic presentations, peer-learning opportunities, and subject matter expert-led discussions. Multiple electronic assessments were distributed to learners over time to measure changes in self-reported knowledge and confidence and to collect feedback on the course. Participating public health programs were also assessed to measure overall course impact. EVALUATION: Among 182 enrolled learners, 94% completed the training. Most learners were infection preventionists (42%) or epidemiologists (38%), had less than 1 year of experience in their health department role (75%), and had less than 1 year of subject matter experience (54%). After training, learners reported increased knowledge and confidence in applying the CDC COVID-19 healthcare IPC guidance for nursing homes (≥81%) with the greatest increase in performing COVID-19 IPC consultations and assessments (87%). The majority of participating programs agreed that the course provided an overall benefit (88%) and reduced training burden (72%). DISCUSSION: The CDC's virtual course was effective in increasing public health capacity for COVID-19 healthcare IPC in nursing homes and provides a possible model to increase IPC capacity for other infectious diseases and other healthcare settings. Future virtual healthcare IPC courses could be enhanced by tailoring materials to health department needs, reinforcing training through applied learning experiences, and supporting mechanisms to retain trained staff.

A single center 10-year clinical experience with superior vena cava retrievable filters.

PURPOSE: To report a 10-year clinical experience with superior vena cava (SVC) retrievable filters. METHODS: A retrospective review of patients with SVC filters was performed between 2008 and 2018 in a single tertiary medical center. Patient demographics, indications for filter placement, type of filter placed, and clinical evolution were recorded. Complications during placement, retrieval, and follow-up were determined. RESULTS: Fifty patients ages 17-89 years (average 54) underwent SVC retrievable filter placement. Main indication for filter placement was deep venous thrombosis of the major upper extremity and/or internal jugular veins with contraindications to anticoagulation. Complications during placement included inadvertent filter placement in the right brachiocephalic vein in two patients, another patient had a leg of the filter entrapped in the tip of a hemodialysis catheter that required filter reposition and line exchange. Thirteen patients had attempted retrieval with 12 filters successfully removed 7-420 days after placement (mean 170). On follow-up images available in 24 patients, 13 filters were noted to be significantly tilted and 10 filters had evidence of leg penetration. No other serious late complications were noted. CONCLUSION: The use of retrievable SVC filters in patients with upper extremity DVT is highly questionable. There is a high incidence of filter malposition, filter tilting, and leg penetration.

Relationships between trait emotion dysregulation and emotional experiences in daily life: an experience sampling study.

Few studies have examined how trait emotion dysregulation relates to momentary affective experiences and the emotion regulation (ER) strategies people use in daily life. In the current study, 112 college students completed a trait measure of emotion dysregulation and completed experience sampling and end-of-day surveys over a two- to three-week period, asking about their emotional experiences and ER strategy use. Participants completed a total of 3798 experience sampling (in-the-moment) and 995 nightly diary surveys. We examined the top 40% of each participant's reported instances of negative affect (to capture times when emotions more likely need regulation). Results indicated that a higher level of trait emotion dysregulation was associated with the following in-the-moment responses: (a) higher level of negative affect; (b) greater desire to change emotions; (c) more attempts to regulate emotion; (d) higher relative endorsements of avoidant (e.g. thought suppression) versus engagement (e.g. acceptance) ER strategy use; and (e) lower perceived effectiveness of ER. Further, individuals with a higher (vs. lower) level of trait emotion dysregulation were less able to identify emotions over the course of the day. Findings demonstrate how trait emotion dysregulation may predict emotional experiences and ER in daily life.

Leveraging Mobile Sensing to Understand and Develop Intervention Strategies to Improve Medication Adherence.

Interventions to improve medication adherence have had limited success and can require significant human resources to implement. Research focused on improving medication adherence has undergone a paradigm shift, of late, with a shift towards developing personalized, theory-driven interventions. The current research integrates foundational and translational science to implement a mechanisms-focused, context-aware approach. Increasing adoption of mobile and wearable sensing systems presents new opportunities for understanding how medication-taking behaviors unfold in natural settings, especially in populations who have difficulty adhering to medications. When combined with survey and ecological momentary assessment data, these mobile and wearable sensing systems can directly capture the context of medication adherence in situ, including personal, behavioral, and environmental factors. The purpose of this paper is to present a new transdisciplinary research framework in medication adherence, highlight critical advances in this rapidly-evolving research field, and outline potential future directions for both research and clinical applications.

Do I really feel better? Effectiveness of emotion regulation strategies depends on the measure and social anxiety.

BACKGROUND: Effective emotion regulation (ER) is important to long-term healthy functioning, but little is known about what constitutes effective ER in the moment or how social anxiety symptoms and different strategies influence short-term effectiveness outcomes. METHODS: Intensive ecological momentary data from N = 124 college students illustrate how different ways of operationalizing ER effectiveness leads to different conclusions about the short-term effectiveness of different strategies in daily life. RESULTS: When effectiveness is operationalized as the degree to which participants judged that their ER attempts made them feel better, social anxiety severity was negatively associated with effectiveness, and avoidance-oriented strategies were judged to be less effective than engagement-oriented strategies. In contrast, when effectiveness is operationalized as the degree of change in self-reported affect following ER attempts, social anxiety severity was not related to effectiveness, and avoidance-oriented strategies were more effective than engagement-oriented strategies. Social anxiety and ER strategy type did not interact in either model, regardless of how effectiveness was measured. CONCLUSIONS: The study highlights discrepancies when examining two common but distinct ways of measuring the same overarching effectiveness construct, and raises intriguing questions about how forms of psychopathology that are intimately tied to emotion dysregulation, like social anxiety, moderate different ways of measuring the effectiveness of ER attempts.

Relative Mortality Analysis Of The "Golden Hour": A Comprehensive Acuity Stratification Approach To Address Disagreement In Current Literature.

OBJECTIVE: This study sought to address the disagreement in literature regarding the "golden hour" in trauma by using the Relative Mortality Analysis to overcome previous studies' limitations in accounting for acuity when evaluating the impact of prehospital time on mortality. METHODS: The previous studies that failed to support the "golden hour" suffered from limitations in their efforts to account for the confounding effects of patient acuity on the relationship between prehospital time and mortality in their trauma populations. The Relative Mortality Analysis was designed to directly address these limitations using a novel acuity stratification approach, based on patients' probability of survival (PoS), a comprehensive triage metric calculated using Trauma and Injury Severity Score methodology. For this analysis, the population selection and analysis methods of these previous studies were compared to the Relative Mortality Analysis on how they capture the relationship between prehospital time and mortality in the University of Virginia (UVA) Trauma Center population. RESULTS: The methods of the previous studies that failed to support the "golden hour" also failed to do so when applied to the UVA Trauma Center population. However, when applied to the same population, the Relative Mortality Analysis identified a subgroup, 9.9% (with a PoS 23%-91%), of the 5,063 patient population with significantly lower mortality when transported to the hospital within 1 hour, supporting the "golden hour." CONCLUSION: These results suggest that previous studies failed to support the "golden hour" not due to a lack of patients significantly impacted by prehospital time within their trauma populations, but instead due to limitations in their efforts to account for patient acuity. As a result, these studies inappropriately rejected the "golden hour," leading to the current disagreement in literature regarding the relationship between prehospital time and trauma patient mortality. The Relative Mortality Analysis was shown to overcome the limitations of these studies and demonstrated that the "golden hour" was significant for patients who were not low acuity (PoS >91%) or severely high acuity (PoS <23%).

Structural connectome differences in HIV infection: brain network segregation associated with nadir CD4 cell count.

This study investigated structural brain organization using diffusion tensor imaging (DTI) in 35 HIV-positive and 35 HIV-negative individuals. We used global and nodal graph theory metrics to investigate whether HIV was associated with differences in brain network organization based on fractional anisotropy (FA) and mean diffusivity (MD). Participants also completed a comprehensive neuropsychological testing battery. For global network metrics, HIV-positive individuals displayed a lower FA clustering coefficient relative to HIV-negative individuals. For nodal network metrics, HIV-positive individuals had less MD nodal degree in the left thalamus. Within HIV-positive individuals, the FA global clustering coefficient was positively correlated with nadir CD4 cell count. Across the sample, cognitive performance was negatively correlated with characteristic path length and positively correlated with global efficiency for FA. These results suggest that, despite management with combination antiretroviral therapy, HIV infection is associated with altered structural brain network segregation and thalamic centrality and that low nadir CD4 cell count may be a risk factor. These graph theory metrics may serve as neural biomarkers to identify individuals at risk for HIV-related neurological complications.

Treatment of Breast Animation Deformity in Implant-Based Reconstruction with Selective Nerve Ablation.

Breast animation deformity is a known complication of subpectoral implant placement that is usually corrected by repositioning the implant to the prepectoral position. Other less common treatment options include performing the muscle splitting biplanar technique, triple plane technique, neuromodulator injections, and secondary neurotomies via transection of the pectoral muscle. We report a patient with animation deformity successfully treated with direct identification and ablation of the medial and lateral pectoral nerves using selective bipolar electrocautery. The patient is a woman with a history of invasive ductal carcinoma who underwent bilateral mastectomy and breast reconstruction with subpectoral implant placement and autologous fat grafting. Within 1 year of her breast reconstruction, she developed hyperactive pectoralis muscle contraction with resulting distortion of both breasts. Given the disadvantages of repositioning the implant to the prepectoral position and transecting the pectoralis muscles via secondary neurotomy, we chose to directly identify and selectively ablate distal branches of the medial and lateral pectoral nerves. This offers a novel technique for correcting breast animation deformity without transecting the pectoralis muscles, causing muscle atrophy, and preserving the subpectoral implant position.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the table of contents or the online instructions to authors www.springer.com/00266 .

The Utility of Viscoelastic Testing in Patients Undergoing IR Procedures.

Whole-blood viscoelastic testing can identify patient-specific coagulation disturbances, allowing for targeted repletion of necessary coagulation factors and differentiation between coagulopathy and surgical bleeding that requires intervention. Viscoelastic testing complements standard coagulation tests and has been shown to decrease transfusion requirements and improve survival in bleeding patients. Viscoelastic testing also can be used to predict bleeding and improve the care of patients undergoing interventional radiology (IR) procedures.

Using Mobile Sensing to Test Clinical Models of Depression, Social Anxiety, State Affect, and Social Isolation Among College Students.

BACKGROUND: Research in psychology demonstrates a strong link between state affect (moment-to-moment experiences of positive or negative emotionality) and trait affect (eg, relatively enduring depression and social anxiety symptoms), and a tendency to withdraw (eg, spending time at home). However, existing work is based almost exclusively on static, self-reported descriptions of emotions and behavior that limit generalizability. Despite adoption of increasingly sophisticated research designs and technology (eg, mobile sensing using a global positioning system [GPS]), little research has integrated these seemingly disparate forms of data to improve understanding of how emotional experiences in everyday life are associated with time spent at home, and whether this is influenced by depression or social anxiety symptoms. OBJECTIVE: We hypothesized that more time spent at home would be associated with more negative and less positive affect. METHODS: We recruited 72 undergraduate participants from a southeast university in the United States. We assessed depression and social anxiety symptoms using self-report instruments at baseline. An app (Sensus) installed on participants' personal mobile phones repeatedly collected in situ self-reported state affect and GPS location data for up to 2 weeks. Time spent at home was a proxy for social isolation. RESULTS: We tested separate models examining the relations between state affect and time spent at home, with levels of depression and social anxiety as moderators. Models differed only in the temporal links examined. One model focused on associations between changes in affect and time spent at home within short, 4-hour time windows. The other 3 models focused on associations between mean-level affect within a day and time spent at home (1) the same day, (2) the following day, and (3) the previous day. Overall, we obtained many of the expected main effects (although there were some null effects), in which higher social anxiety was associated with more time or greater likelihood of spending time at home, and more negative or less positive affect was linked to longer homestay. Interactions indicated that, among individuals higher in social anxiety, higher negative affect and lower positive affect within a day was associated with greater likelihood of spending time at home the following day. CONCLUSIONS: Results demonstrate the feasibility and utility of modeling the relationship between affect and homestay using fine-grained GPS data. Although these findings must be replicated in a larger study and with clinical samples, they suggest that integrating repeated state affect assessments in situ with continuous GPS data can increase understanding of how actual homestay is related to affect in everyday life and to symptoms of anxiety and depression.