The BLISTER Score: A Novel, Externally Validated Tool for Predicting Cardiac Implantable Electronic Device Infections, and Its Cost-Utility Implications for Antimicrobial Envelope Use.

BACKGROUND: Antimicrobial envelopes reduce the incidence of cardiac implantable electronic device infections, but their cost restricts routine use in the United Kingdom. Risk scoring could help to identify which patients would most benefit from this technology. METHODS: A novel risk score (BLISTER [Blood results, Long procedure time, Immunosuppressed, Sixty years old (or younger), Type of procedure, Early re-intervention, Repeat procedure]) was derived from multivariate analysis of factors associated with cardiac implantable electronic device infection. Diagnostic utility was assessed against the existing PADIT score (Prior procedure, Age, Depressed renal function, Immunocompromised, Type of procedure) in both standard and high-risk external validation cohorts, and cost-utility models examined different BLISTER and PADIT score thresholds for TYRX (Medtronic; Minneapolis, MN) antimicrobial envelope allocation. RESULTS: In a derivation cohort (n=7383), cardiac implantable electronic device infection occurred in 59 individuals within 12 months of a procedure (event rate, 0.8%). In addition to the PADIT score constituents, lead extraction (hazard ratio, 3.3 [95% CI, 1.9-6.1]; P<0.0001), C-reactive protein >50 mg/L (hazard ratio, 3.0 [95% CI, 1.4-6.4]; P=0.005), reintervention within 2 years (hazard ratio, 10.1 [95% CI, 5.6-17.9]; P<0.0001), and top-quartile procedure duration (hazard ratio, 2.6 [95% CI, 1.6-4.1]; P=0.001) were independent predictors of infection. The BLISTER score demonstrated superior discriminative performance versus PADIT in the standard risk (n=2854, event rate: 0.8%, area under the curve, 0.82 versus 0.71; P=0.001) and high-risk validation cohorts (n=1961, event rate: 2.0%, area under the curve, 0.77 versus 0.69; P=0.001), and in all patients (n=12 198, event rate: 1%, area under the curve, 0.8 versus 0.75, P=0.002). In decision-analytic modeling, the optimum scenario assigned antimicrobial envelopes to patients with BLISTER scores ≥6 (10.8%), delivering a significant reduction in infections (relative risk reduction, 30%; P=0.036) within the National Institute for Health and Care Excellence cost-utility thresholds (incremental cost-effectiveness ratio, £18 446). CONCLUSIONS: The BLISTER score (https://qxmd.com/calculate/calculator_876/the-blister-score-for-cied-infection) was a valid predictor of cardiac implantable electronic device infection, and could facilitate cost-effective antimicrobial envelope allocation to high-risk patients.

Equity Concerns Across Pediatric Research Recruitment: An Analysis of Research Staff Interviews.

BACKGROUND AND OBJECTIVES: Difficulty recruiting individuals from minoritized and underserved populations for clinical research is well documented and has health equity implications. Previously, we reported findings from interviews with research staff about pediatric research recruitment processes. Respondents raised equity concerns related to recruitment and enrollment of participants from minoritized, low resourced, and underserved populations. We therefore decided to perform a secondary coding of the transcripts to examine equity-related issues systematically. METHODS: We conducted a process of secondary coding and analysis of interviews with research staff involved in recruitment for pediatric clinical research. Through consensus we identified codes relevant to equity and developed a conceptual framework including 5 stages of research. RESULTS: We analyzed 28 interviews and coded equity-related items. We report 6 implications of our findings. First, inequitable access to clinical care is an upstream barrier to research participation. Second, there is a need to increase research opportunities where underserved and under-represented populations receive care. Third, increasing research team diversity can build trust with patients and families, but teams must ensure adequate support of all research team members. Fourth, issues related to consent processes raise institutional-level opportunities for improvement. Fifth, there are numerous study procedure-related barriers to participation. Sixth, our analysis illustrates that individuals who speak languages other than English face barriers across multiple stages. CONCLUSIONS: Research staff members identified equity-related concerns and recommended potential solutions across 5 stages of the research process, which may guide those endeavoring to improve research recruitment for pediatric patients from minoritized and underserved populations.

Race and Ethnicity of Infants Enrolled in Neonatal Clinical Trials: A Systematic Review.

Importance: Representativeness of populations within neonatal clinical trials is crucial to moving the field forward. Although racial and ethnic disparities in research inclusion are well documented in other fields, they are poorly described within neonatology. Objective: To describe the race and ethnicity of infants included in a sample of recent US neonatal clinical trials and the variability in this reporting. Evidence Review: A systematic search of US neonatal clinical trials entered into Cochrane CENTRAL 2017 to 2021 was conducted. Two individuals performed inclusion determination, data extraction, and quality assessment independently with discrepancies adjudicated by consensus. Findings: Of 120 studies with 14 479 participants that met the inclusion criteria, 75 (62.5%) included any participant race or ethnicity data. In the studies that reported race and ethnicity, the median (IQR) percentage of participants of each background were 0% (0%-1%) Asian, 26% (9%-42%) Black, 3% (0%-12%) Hispanic, 0% (0%-0%) Indigenous (eg, Alaska Native, American Indian, and Native Hawaiian), 0% (0%-0%) multiple races, 57% (30%-68%) White, and 7% (1%-21%) other race or ethnicity. Asian, Black, Hispanic, and Indigenous participants were underrepresented, while White participants were overrepresented compared with a reference sample of the US clinical neonatal intensive care unit (NICU) population from the Vermont Oxford Network. Many participants were labeled as other race or ethnicity without adequate description. There was substantial variability in terms and methods of reporting race and ethnicity data. Geographic representation was heavily skewed toward the Northeast, with nearly one-quarter of states unrepresented. Conclusions and Relevance: These findings suggest that neonatal research may perpetuate inequities by underrepresenting Asian, Black, Hispanic, and Indigenous neonates in clinical trials. Studies varied in documentation of race and ethnicity, and there was regional variation in the sites included. Based on these findings, funders and clinical trialists are advised to consider a 3-point targeted approach to address these issues: prioritize identifying ways to increase diversity in neonatal clinical trial participation, agree on a standardized method to report race and ethnicity among neonatal clinical trial participants, and prioritize the inclusion of participants from all regions of the US in neonatal clinical trials.

Life-Cycle Assessment of Ti3 C2 Tx MXene Synthesis.

MXenes, 2D transition metal carbides, nitrides, and carbonitrides, have been investigated for diverse applications since their discovery; however, their life-cycle assessment (LCA) has not been studied. Here, a "cradle to gate" LCA is performed to assess the cumulative energy demand (CED) and environmental impacts of lab-scale synthesis of Ti3 C2 Tx , the most researched MXene composition. Electromagnetic interface (EMI) shielding is selected as it is one of MXenes' most promising applications and LCA of Ti3 C2 Tx synthesis is compared to aluminum and copper foils, two typical EMI-shielding materials. Two laboratory-scale MXene synthesis systems-gram and kilogram batches-are examined. The CED and environmental implications of Ti3 C2 Tx synthesis are investigated based on its precursor production, selective etching, delamination processes, laboratory location, energy mix, and raw material type. These results show that laboratory electricity usage for the synthesis processes accounts for >70% of the environmental impacts. Manufacturing 1.0 kg of industrial-scale aluminum and copper foil releases 23.0 kg and 8.75 kg of CO2 , respectively, while 1.0 kg of lab-scale MXene synthesis releases 428.10 kg. Chemical usage is less impactful than electricity, which suggests that recycled resources and renewable energy can make MXene synthesis more sustainable. Understanding MXene LCA helps the industrialization of this material.

Evaluating Mentors in Violence Prevention: A Longitudinal, Multilevel Assessment of Outcome Changes.

There is a need to increase understanding of the effectiveness of bystander programmes targeting gender-based violence in the United Kingdom. There is also a need to utilise a robust theoretical models of decision-making while doing so. Changes were examined in bystanders' attitudes, beliefs, motivations towards intervening, and intervention behavior in situations of gender-based violence. To achieve this, a quantitative examination of Mentors in Violence Prevention was conducted. There were 1396 participants (50% female, 50% male) who were aged 11 to 14 years old (M = 12.25, SD = 0.84) attending high school at the first time point. Participants were attending 17 schools (53% Mentors in Violence Prevention and 47% control) in Scotland. Outcome variables were assessed approximately one year apart using questionnaires. Multilevel linear regressions revealed that Mentors in Violence Prevention did not change outcomes reflecting bystanders' attitudes, beliefs, motivations towards intervening, or intervention behavior in gender-based violence. Discrepancies between the current findings and those of other evaluations may be due to other studies including small numbers of schools that may be more motivated to implement the program. This study also identified two key issues that need to be addressed at stakeholder level before concluding that Mentors in Violence Prevention is ineffective at targeting gender-based violence. That the program has moved towards a more gender-neutral approach in the United Kingdom could explain the null results of this study. Furthermore, the current findings could be attributed to a failure to adequately address the theoretical model underpinning the program in practice.

Parental Views of Facilitators and Barriers to Research Participation: Systematic Review.

BACKGROUND AND OBJECTIVES: Low enrollment within pediatric research increases the cost of research, decreases generalizability, and threatens to exacerbate existing health disparities. To assess barriers and facilitators to pediatric research participation and evaluate differences by enrollment status. METHODS: Data Sources include PubMed, Embase, PsycInfo, Cumulative Index to Nursing and Allied Health Literature, and Web of Science. Study selection include peer reviewed articles that contained information related to facilitators and barriers to the parental decision whether to enroll their child in research and included the views of parents who declined. We extracted barriers and facilitators to research, enrollment status, and study characteristics, including study design, quality, and patient population. RESULTS: Seventy articles were included for analysis. Facilitators of participation included: benefits, trust, support of research, informational and consent related, and relational issues. Common facilitators within those categories included health benefit to child (N = 39), altruism (N = 30), and the importance of research (N = 26). Barriers to participation included: study-related concerns, burdens of participation, lack of trust, general research concerns, informational and consent related, and relational issues. Common barriers within those categories included risks to child (N = 46), burdens of participation (N = 35), and the stress of the decision (N = 29). We had a limited ability to directly compare by enrollment status and no ability to analyze interactions between facilitators and barriers. We only included studies written in English. CONCLUSIONS: This review identified key facilitators and barriers to research participation in pediatrics. The findings from this review may guide researchers aiming to create interventions to improve the parental experience of recruitment for pediatric studies and to optimize enrollment rates.

Cost-effectiveness of outpatient versus inpatient non-invasive ventilation setup in obesity hypoventilation syndrome: the OPIP trial.

BACKGROUND: Current guidelines recommend that patients with obesity hypoventilation syndrome (OHS) are electively admitted for inpatient initiation of home non-invasive ventilation (NIV). We hypothesised that outpatient NIV setup would be more cost-effective. METHODS: Patients with stable OHS referred to six participating European centres for home NIV setup were recruited to an open-labelled clinical trial. Patients were randomised via web-based system using stratification to inpatient setup, with standard fixed level NIV and titrated during an attended overnight respiratory study or outpatient setup using an autotitrating NIV device and a set protocol, including home oximetry. The primary outcome was cost-effectiveness at 3 months with daytime carbon dioxide (PaCO2) as a non-inferiority safety outcome; non-inferiority margin 0.5 kPa. Data were analysed on an intention-to-treat basis. Health-related quality of life (HRQL) was measured using EQ-5D-5L (5 level EQ-5D tool) and costs were converted using purchasing power parities to £(GBP). RESULTS: Between May 2015 and March 2018, 82 patients were randomised. Age 59±14 years, body mass index 47±10 kg/m2 and PaCO2 6.8±0.6 kPa. Safety analysis demonstrated no difference in ∆PaCO2 (difference -0.27 kPa, 95% CI -0.70 to 0.17 kPa). Efficacy analysis showed similar total per-patient costs (inpatient £2962±£580, outpatient £3169±£525; difference £188.20, 95% CI -£61.61 to £438.01) and similar improvement in HRQL (EQ-5D-5L difference -0.006, 95% CI -0.05 to 0.04). There were no differences in secondary outcomes. DISCUSSION: There was no difference in medium-term cost-effectiveness, with similar clinical effectiveness, between outpatient and inpatient NIV setup. The home NIV setup strategy can be led by local resource demand and patient and clinician preference. TRIAL REGISTRATION NUMBERS: NCT02342899 and ISRCTN51420481.

Clinical effectiveness of a dedicated cardiac resynchronization therapy pre-assessment clinic incorporating cardiac magnetic resonance imaging and cardiopulmonary exercise testing on patient selection and outcomes.

BACKGROUND: Pre-procedural assessment of patients undergoing cardiac resynchronization therapy (CRT) is heterogenous and patients implanted with unfavorable characteristics may account for non-response. A dedicated CRT pre-assessment clinic (CRT PAC) was developed to standardize the review process and undertake structured pre-procedural evaluation. The aim of this analysis was to determine the effectiveness on patient selection and outcomes. METHODS: A prospective database of consecutive patients attending the CRT PAC between 2013 and 2018 was analyzed. Pre-operative assessment included cardiac magnetic resonance (CMR) and cardiopulmonary exercise testing (CPET). Patients were considered CRT responders based on improvement in clinical composite score (CCS) and/or reduction in left ventricular end-systolic volume (LVESV) ≥ 15% at 6-months follow-up. RESULTS: Of 252 patients reviewed in the CRT PAC during the analysis period, 192 fulfilled consensus guidelines for implantation. Of the patients receiving CRT, 82% showed improvement in their CCS and 57% had a reduction in LVESV ≥ 15%. The presence of subendocardial scar on CMR and a peak VO2 ≤ 12 ml/kg/min on CPET predicted CRT non-response. Two patients were unsuitable for CRT as they had end-stage heart failure and died during follow-up. The majority of patients initially deemed unsuitable for CRT did not suffer from unexpected hospitalization for decompensated heart failure or died from cardiovascular disease; only 8 patients (13%) received CRT devices during follow-up because of symptomatic left ventricular systolic impairment. CONCLUSION: A dedicated CRT PAC is able to appropriately select patients for CRT. Pre-procedural investigation/imaging can identify patients unlikely to respond to, or may not yet be suitable for CRT.

Noninvasive electrocardiographic assessment of ventricular activation and remodeling response to cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) produces acute changes in electric resynchronization that can be measured noninvasively with electrocardiographic body surface mapping (ECGi). The relation between baseline acute electrophysiology metrics and their manipulation with CRT and reverse remodeling is unclear. OBJECTIVE: To test (ECGi) derived parameters of electrical activation as predictors of volumetric response to CRT. METHODS: ECGi was performed in 21 patients directly following CRT implant. Activation parameters (left ventricular total activation time [LVtat], global biventricular total activation time [VVtat], global left/right ventricular electrical synchrony [VVsync], and global left ventricular dispersion of activation times [LVdisp]) were measured at baseline and following echocardiographically optimized CRT. Remodeling response (>15% reduction left ventricular end-systolic volume) was assessed 6 months post CRT. RESULTS: Patients were aged 68.9 ± 12.1 years, 81% were male, and 57% were ischemic. Baseline measures of dyssynchrony were more pronounced in left bundle branch block (LBBB) vs non-LBBB. ECGi demonstrated a trend of greater interventricular dyssynchrony between responders and nonresponders that did not reach statistical significance (VVsync: -45.7 ± 22.4 ms vs -25.1 ± 29.3 ms, P = .227). Remaining activation parameters were similar between responders and nonresponders (VVtat 101 ± 22.0 ms vs 98.9 ± 23.4 ms, P = .838; LVtat 86.4 ± 17.1 ms vs 85.1 ± 27.7 ms, P = .904; LVdisp 28.2 ± 6.3 ms vs 27.0 ± 8.7 ms, P = .726). In volumetric responders activation parameters were significantly improved with CRT compared to nonresponders: VV sync (-45.67 ± 22.41 ms vs 2.33±18.87 ms, P = .001), VVtat (101 ± 22.04 ms vs 71 ± 14.01 ms, P = .002), LVtat (86.44 ± 17.15 ms vs 67.67 ± 11.31 ms, P = .006), and LVdisp (28.22 ± 6.3 ms vs 21.56 ± 4.45 ms, P = .008). CONCLUSION: Baseline ECGi activation times did not predict CRT volumetric response. Volumetric responders exhibited significant improvements in ECGi-derived metrics with CRT. ECGi does not select CRT candidates but may be a useful adjunct to guide left ventricle lead implants and to perform postimplant CRT optimization.

Assessment of Sleepiness in Drivers: Current Methodology and Future Possibilities.

Many patients with obstructive sleep apnea syndrome (OSAS) drive a vehicle both for pleasure and as part of their employment. Some, but not all, patients with OSAS are at increased risk of being involved in road traffic accidents. Clinicians are often asked to make recommendations about an individual's fitness to drive, and these are likely to be inconsistent in the absence of objective criteria. This article discusses the current practice of the assessment of individuals' sleepiness with respect to driving, the limitations of available techniques, and future possibilities.

Home-Based Training Support for Stroke Patients Using the Leap Motion and StandInExercise Stand.

Rehabilitation aims at brain rewiring through intensive practice following brain injury. This paper presents a new supportive mechanism that will be used to isolate wrist movement and in combination to the use of serious games, to act as a motivational tool to improve adherence during home-based practice. The paper describes the proposed methodology employed to carry out the home-based programme while leap motion is used to monitor and evaluate these exercises.

Characteristics Associated With Preferences for Parent-Centered Decision Making in Neonatal Intensive Care.

Importance: Little is known about how characteristics of particular clinical decisions influence decision-making preferences by patients or their surrogates. A better understanding of the factors underlying preferences is essential to improve the quality of shared decision making. Objective: To identify the characteristics of particular decisions that are associated with parents' preferences for family- vs medical team-centered decision making across the spectrum of clinical decisions that arise in the neonatal intensive care unit (NICU). Design, Setting, and Participants: This cross-sectional survey assessed parents' preferences for parent- vs medical team-centered decision making across 16 clinical decisions, along with parents' assessments of 7 characteristics of those decisions. Respondents included 136 parents of infants in 1 of 3 academically affiliated hospital NICUs in Philadelphia, Pennsylvania, from January 7 to July 8, 2016. Respondents represented a wide range of educational levels, employment status, and household income but were predominantly female (109 [80.1%]), white (68 [50.0%]) or African American (53 [39.0%]), and married (81 of 132 responding [61.4%]). Main Outcomes and Measures: Preferences for parent-centered decision making. For each decision characteristic (eg, urgency), multivariable analyses tested whether middle and high levels of that characteristic (compared with low levels) were associated with a preference for parent-centered decision making, resulting in 2 odds ratios (ORs) per decision characteristic. Results: Among the 136 respondents (109 women [80.1%] and 27 men [19.9%]; median age, 30 years [range, 18-43 years]), preferences for parent-centered decision making were positively associated with decisions that involved big-picture goals (middle OR, 2.01 [99% CI, 0.83-4.86]; high OR, 3.38 [99% CI, 1.48-7.75]) and that had the potential to harm the infant (middle OR, 1.32 [99% CI, 0.84-2.08]; high OR, 2.62 [99% CI, 1.67-4.11]). In contrast, preferences for parent-centered decision making were inversely associated with the following 4 decision characteristics: technical decisions (middle OR, 0.82 [99% CI, 0.45-1.52]; high OR, 0.48 [99% CI, 0.25-0.93]), the potential to benefit the infant (middle OR, 0.42 [99% CI, 0.16-1.05]; high OR, 0.21 [99% CI, 0.08-0.52]), requires medical expertise (middle OR, 0.48 [99% CI, 0.22-1.05]; high OR, 0.21 [99% CI, 0.10-0.48]), and a high level of urgency (middle OR, 0.47 [99% CI, 0.24-0.92]; high OR, 0.42 [99% CI, 0.22-0.83]). Conclusions and Relevance: Preferences for parent-centered vs medical team-centered decision making among parents of infants in the NICU may vary systematically by the characteristics of particular clinical decisions. Incorporating this variation into shared decision making and endorsing models that allow parents to cede control to physicians in appropriate clinical circumstances might improve the quality and outcomes of medical decisions.

Quantitative assessment of structural image quality.

Data quality is increasingly recognized as one of the most important confounding factors in brain imaging research. It is particularly important for studies of brain development, where age is systematically related to in-scanner motion and data quality. Prior work has demonstrated that in-scanner head motion biases estimates of structural neuroimaging measures. However, objective measures of data quality are not available for most structural brain images. Here we sought to identify quantitative measures of data quality for T1-weighted volumes, describe how these measures relate to cortical thickness, and delineate how this in turn may bias inference regarding associations with age in youth. Three highly-trained raters provided manual ratings of 1840 raw T1-weighted volumes. These images included a training set of 1065 images from Philadelphia Neurodevelopmental Cohort (PNC), a test set of 533 images from the PNC, as well as an external test set of 242 adults acquired on a different scanner. Manual ratings were compared to automated quality measures provided by the Preprocessed Connectomes Project's Quality Assurance Protocol (QAP), as well as FreeSurfer's Euler number, which summarizes the topological complexity of the reconstructed cortical surface. Results revealed that the Euler number was consistently correlated with manual ratings across samples. Furthermore, the Euler number could be used to identify images scored "unusable" by human raters with a high degree of accuracy (AUC: 0.98-0.99), and out-performed proxy measures from functional timeseries acquired in the same scanning session. The Euler number also was significantly related to cortical thickness in a regionally heterogeneous pattern that was consistent across datasets and replicated prior results. Finally, data quality both inflated and obscured associations with age during adolescence. Taken together, these results indicate that reliable measures of data quality can be automatically derived from T1-weighted volumes, and that failing to control for data quality can systematically bias the results of studies of brain maturation.

DiPALS: Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis - a randomised controlled trial.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease resulting in death, usually from respiratory failure, within 2-3 years of symptom onset. Non-invasive ventilation (NIV) is a treatment that when given to patients in respiratory failure leads to improved survival and quality of life. Diaphragm pacing (DP), using the NeuRx/4(®) diaphragm pacing system (DPS)™ (Synapse Biomedical, Oberlin, OH, USA), is a new technique that may offer additional or alternative benefits to patients with ALS who are in respiratory failure. OBJECTIVE: The Diaphragm Pacing in patients with Amyotrophic Lateral Sclerosis (DiPALS) trial evaluated the effect of DP on survival over the study duration in patients with ALS with respiratory failure. DESIGN: The DiPALS trial was a multicentre, parallel-group, open-label, randomised controlled trial incorporating health economic analyses and a qualitative longitudinal substudy. PARTICIPANTS: Eligible participants had a diagnosis of ALS (ALS laboratory-supported probable, clinically probable or clinically definite according to the World Federation of Neurology revised El Escorial criteria), had been stabilised on riluzole for 30 days, were aged ≥ 18 years and were in respiratory failure. We planned to recruit 108 patients from seven UK-based specialist ALS or respiratory centres. Allocation was performed using 1 : 1 non-deterministic minimisation. INTERVENTIONS: Participants were randomised to either standard care (NIV alone) or standard care (NIV) plus DP using the NeuRX/4 DPS. MAIN OUTCOME MEASURES: The primary outcome was overall survival, defined as the time from randomisation to death from any cause. Secondary outcomes were patient quality of life [assessed by European Quality of Life-5 Dimensions, three levels (EQ-5D-3L), Short Form questionnaire-36 items and Sleep Apnoea Quality of Life Index questionnaire]; carer quality of life (EQ-5D-3L and Caregiver Burden Inventory); cost-utility analysis and health-care resource use; tolerability and adverse events. Acceptability and attitudes to DP were assessed in a qualitative substudy. RESULTS: In total, 74 participants were randomised into the trial and analysed, 37 participants to NIV plus pacing and 37 to standard care, before the Data Monitoring and Ethics Committee advised initial suspension of recruitment (December 2013) and subsequent discontinuation of pacing (on safety grounds) in all patients (June 2014). Follow-up assessments continued until the planned end of the study in December 2014. The median survival (interquartile range) was 22.5 months (lower quartile 11.8 months; upper quartile not reached) in the NIV arm and 11.0 months (6.7 to 17.0 months) in the NIV plus pacing arm, with an adjusted hazard ratio of 2.27 (95% confidence interval 1.22 to 4.25; p = 0.01). CONCLUSIONS: Diaphragmatic pacing should not be used as a routine treatment for patients with ALS in respiratory failure. FUTURE WORK: It may be that certain population subgroups benefit from DP. We are unable to explain the mechanism behind the excess mortality in the pacing arm, something the small trial size cannot help address. Future research should investigate the mechanism by which harm or benefit occurs further. TRIAL REGISTRATION: Current Controlled Trials ISRCTN53817913. FUNDING: This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 45. See the HTA programme website for further project information. Additional funding was provided by the Motor Neurone Disease Association of England, Wales and Northern Ireland.

The impact of quality assurance assessment on diffusion tensor imaging outcomes in a large-scale population-based cohort.

BACKGROUND: Diffusion tensor imaging (DTI) is applied in investigation of brain biomarkers for neurodevelopmental and neurodegenerative disorders. However, the quality of DTI measurements, like other neuroimaging techniques, is susceptible to several confounding factors (e.g., motion, eddy currents), which have only recently come under scrutiny. These confounds are especially relevant in adolescent samples where data quality may be compromised in ways that confound interpretation of maturation parameters. The current study aims to leverage DTI data from the Philadelphia Neurodevelopmental Cohort (PNC), a sample of 1601 youths with ages of 8-21 who underwent neuroimaging, to: 1) establish quality assurance (QA) metrics for the automatic identification of poor DTI image quality; 2) examine the performance of these QA measures in an external validation sample; 3) document the influence of data quality on developmental patterns of typical DTI metrics. METHODS: All diffusion-weighted images were acquired on the same scanner. Visual QA was performed on all subjects completing DTI; images were manually categorized as Poor, Good, or Excellent. Four image quality metrics were automatically computed and used to predict manual QA status: Mean voxel intensity outlier count (MEANVOX), Maximum voxel intensity outlier count (MAXVOX), mean relative motion (MOTION) and temporal signal-to-noise ratio (TSNR). Classification accuracy for each metric was calculated as the area under the receiver-operating characteristic curve (AUC). A threshold was generated for each measure that best differentiated visual QA status and applied in a validation sample. The effects of data quality on sensitivity to expected age effects in this developmental sample were then investigated using the traditional MRI diffusion metrics: fractional anisotropy (FA) and mean diffusivity (MD). Finally, our method of QA is compared with DTIPrep. RESULTS: TSNR (AUC=0.94) best differentiated Poor data from Good and Excellent data. MAXVOX (AUC=0.88) best differentiated Good from Excellent DTI data. At the optimal threshold, 88% of Poor data and 91% Good/Excellent data were correctly identified. Use of these thresholds on a validation dataset (n=374) indicated high accuracy. In the validation sample 83% of Poor data and 94% of Excellent data was identified using thresholds derived from the training sample. Both FA and MD were affected by the inclusion of poor data in an analysis of an age, sex and race matched comparison sample. In addition, we show that the inclusion of poor data results in significant attenuation of the correlation between diffusion metrics (FA and MD) and age during a critical neurodevelopmental period. We find higher correspondence between our QA method and DTIPrep for Poor data, but we find our method to be more robust for apparently high-quality images. CONCLUSION: Automated QA of DTI can facilitate large-scale, high-throughput quality assurance by reliably identifying both scanner and subject induced imaging artifacts. The results present a practical example of the confounding effects of artifacts on DTI analysis in a large population-based sample, and suggest that estimates of data quality should not only be reported but also accounted for in data analysis, especially in studies of development.

Amotivation in schizophrenia: integrated assessment with behavioral, clinical, and imaging measures.

Motivational deficits play a central role in disability caused by schizophrenia and constitute a major unmet therapeutic need. Negative symptoms have previously been linked to hypofunction in ventral striatum (VS), a core component of brain motivation circuitry. However, it remains unclear to what extent this relationship holds for specific negative symptoms such as amotivation, and this question has not been addressed with integrated behavioral, clinical, and imaging measures. Here, 41 individuals with schizophrenia and 37 controls performed a brief, computerized progressive ratio task (PRT) that quantifies effort exerted in pursuit of monetary reward. Clinical amotivation was assessed using the recently validated Clinical Assessment Interview for Negative Symptoms (CAINS). VS function was probed during functional magnetic resonance imaging using a monetary guessing paradigm. We found that individuals with schizophrenia had diminished motivation as measured by the PRT, which significantly and selectively related to clinical amotivation as measured by the CAINS. Critically, lower PRT motivation in schizophrenia was also dimensionally related to VS hypofunction. Our results demonstrate robust dimensional associations between behavioral amotivation, clinical amotivation, and VS hypofunction in schizophrenia. Integrating behavioral measures such as the PRT will facilitate translational efforts to identify biomarkers of amotivation and to assess response to novel therapeutic interventions.

Climate-related hazards: a method for global assessment of urban and rural population exposure to cyclones, droughts, and floods.

Global climate change (GCC) has led to increased focus on the occurrence of, and preparation for, climate-related extremes and hazards. Population exposure, the relative likelihood that a person in a given location was exposed to a given hazard event(s) in a given period of time, was the outcome for this analysis. Our objectives were to develop a method for estimating the population exposure at the country level to the climate-related hazards cyclone, drought, and flood; develop a method that readily allows the addition of better datasets to an automated model; differentiate population exposure of urban and rural populations; and calculate and present the results of exposure scores and ranking of countries based on the country-wide, urban, and rural population exposures to cyclone, drought, and flood. Gridded global datasets on cyclone, drought and flood occurrence as well as population density were combined and analysis was carried out using ArcGIS. Results presented include global maps of ranked country-level population exposure to cyclone, drought, flood and multiple hazards. Analyses by geography and human development index (HDI) are also included. The results and analyses of this exposure assessment have implications for country-level adaptation. It can also be used to help prioritize aid decisions and allocation of adaptation resources between countries and within a country. This model is designed to allow flexibility in applying cyclone, drought and flood exposure to a range of outcomes and adaptation measures.

Real-time automated spectral assessment of the BOLD response for neurofeedback at 3 and 7T.

Echo-planar imaging is the dominant functional MRI data acquisition scheme for evaluating the BOLD signal. To date, it remains the only approach providing neurofeedback from spatially localized brain activity. Real-time functional single-voxel proton spectroscopy (fSVPS) may be an alternative for spatially specific BOLD neurofeedback at 7T because it allows for a precise estimation of the local T2* signal, EPI-specific artifacts may be avoided, and the signal contrast may increase. In order to explore and optimize this alternative neurofeedback approach, we tested fully automated real-time fSVPS spectral estimation procedures to approximate T2* BOLD signal changes from the unsuppressed water peak, i.e. lorentzian non-linear complex spectral fit (LNLCSF) in frequency and frequency-time domain. The proposed approaches do not require additional spectroscopic localizers in contrast to conventional T2* approximation based on linear regression of the free induction decay (FID). For methods comparison, we evaluated quality measures for signals from the motor and the visual cortex as well as a real-time feedback condition at high (3T) and at ultra-high (7T) magnetic field strengths. Using these methods, we achieved reliable and fast water peak spectral parameter estimations. At 7T, we observed an absolute increase of spectra line narrowing due to the BOLD effect, but quality measures did not improve due to artifactual line broadening. Overall, the automated fSVPS approach can be used to assess dynamic spectral changes in real-time, and to provide localized T2* neurofeedback at 3 and 7T.