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The article discusses various abstracts presented at the Neurocritical Care Society's 22nd Annual Meeting in 2024, covering topics such as brain oxygen optimization, sedation use in neurologic coma patients, glymphatic system in post-traumatic epilepsy, and withdrawal of life-sustaining therapy in traumatic brain injury cases. The lack of consistent information on brain death determination on state health organization websites underscores the need for standardized education in this area. Studies on intracranial hemorrhage in chronic myeloid leukemia patients, delirium in subarachnoid hemorrhage patients, and EEG networks in nonagenarians with dementia provide valuable insights into improving patient outcomes in neurocritical care. The CRANBeRI-ML algorithm shows promise in guiding post-operative care decisions for patients undergoing elective craniotomy for brain tumors. The study evaluating AHA/ASA guidelines for aneurysmal subarachnoid hemorrhage and primary intracerebral hemorrhage highlights the need for improvement in evidence and recommendations in these areas. [Extracted from the article]

Background: Clinical management of persons with disorders of consciousness (DoC) is dedicated largely to optimizing recovery. However, selecting a measure to evaluate the extent of recovery is challenging because few measures are designed to precisely assess the full range of potential outcomes, from prolonged DoC to return of preinjury functioning. Measures that are designed specifically to assess persons with DoC are often performance-based and only validated for in-person use. Moreover, there are no published recommendations addressing which outcome measures should be used to evaluate DoC recovery. The resulting inconsistency in the measures selected by individual investigators to assess outcome prevents comparison of results across DoC studies. The National Institute of Neurological Disorders and Stroke (NINDS) common data elements (CDEs) is an amalgamation of standardized variables and tools that are recommended for use in studies of neurologic diseases and injuries. The Neurocritical Care Society Curing Coma Campaign launched an initiative to develop CDEs specifically for DoC and invited our group to recommend CDE outcomes and endpoints for persons with DoCs. Methods: The Curing Coma Campaign Outcomes and Endpoints CDE Workgroup, consisting of experts in adult and pediatric neurocritical care, neurology, and neuroscience, used a previously established five-step process to identify and select candidate CDEs: (1) review of existing NINDS CDEs, (2) nomination and systematic vetting of new CDEs, (3) CDE classification, (4) iterative review and approval of panel recommendations, and (5) development of case report forms. Results: Among hundreds of existing NINDS outcome and endpoint CDE measures, we identified 20 for adults and 18 for children that can be used to assess the full range of recovery from coma. We also proposed 14 new outcome and endpoint CDE measures for adults and 5 for children. Conclusions: The DoC outcome and endpoint CDEs are a starting point in the broader effort to standardize outcome evaluation of persons with DoC. The ultimate goal is to harmonize DoC studies and allow for more precise assessment of outcomes after severe brain injury or illness. An iterative approach is required to modify and adjust these outcome and endpoint CDEs as new evidence emerges. [ABSTRACT FROM AUTHOR]

Background: The recent publication of practice guidelines for management of patients with disorders of consciousness (DoC) in the United States and Europe was a major step forward in improving the accuracy and consistency of terminology, diagnostic criteria, and prognostication in this population. There remains a pressing need for a more precise brain injury classification system that combines clinical semiology with neuroimaging, electrophysiologic, and other biomarker data. To address this need, the National Institute of Neurological Disorders and Stroke launched the Common Data Elements (CDEs) initiative to facilitate systematic collection of high-quality research data in studies involving patients with neurological disease. The Neurocritical Care Society's Curing Coma Campaign expanded this effort in 2018 to develop CDEs for DoC. Herein, we present CDE recommendations for behavioral phenotyping of patients with DoC. Methods: The Behavioral Phenotyping Workgroup used a preestablished, five-step process to identify and select candidate CDEs that included review of existing National Institute of Neurological Disorders and Stroke CDEs, nomination and systematic vetting of new CDEs, CDE classification, iterative review, and approval of panel recommendations and development of corresponding case review forms. Results: We identified a slate of existing and newly proposed basic, supplemental, and exploratory CDEs that can be used for behavioral phenotyping of adult and pediatric patients with DoC. Conclusions: The proposed behavioral phenotyping CDEs will assist with international harmonization of DoC studies and allow for more precise characterization of study cohorts, favorably impacting observational studies and clinical trials aimed at improving outcome in this population. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Common Data Elements for Disorders of Consciousness: Recommendations from the Working Group on Physiology and Big Data" published in the journal Neurocritical Care. The correction adds the middle initial for co-author Eric S. Rosenthal. The document also includes a list of the Curing Coma Campaign Collaborators, who contributed to the article. The publisher, Springer Nature, remains neutral with regard to jurisdictional claims and institutional affiliations. [Extracted from the article]

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest. [ABSTRACT FROM AUTHOR]

Background: Over the past 30 years, there have been significant advances in the understanding of the mechanisms associated with loss and recovery of consciousness following severe brain injury. This work has provided a strong grounding for the development of novel restorative therapeutic interventions. Although all interventions are aimed at modulating and thereby restoring brain function, the landscape of existing interventions encompasses a very wide scope of techniques and protocols. Despite vigorous research efforts, few approaches have been assessed with rigorous, high-quality randomized controlled trials. As a growing number of exploratory interventions emerge, it is paramount to develop standardized approaches to reporting results. The successful evaluation of novel interventions depends on implementation of shared nomenclature and infrastructure. To address this gap, the Neurocritical Care Society's Curing Coma Campaign convened nine working groups and charged them with developing common data elements (CDEs). Here, we report the work of the Therapeutic Interventions Working Group. Methods: The working group reviewed existing CDEs relevant to therapeutic interventions within the National Institutes of Health National Institute of Neurological Disorders and Stroke database and reviewed the literature for assessing key areas of research in the intervention space. CDEs were then proposed, iteratively discussed and reviewed, classified, and organized in a case report form (CRF). Results: We developed a unified CRF, including CDEs and key design elements (i.e., methodological or protocol parameters), divided into five sections: (1) patient information, (2) general study information, (3) behavioral interventions, (4) pharmacological interventions, and (5) device interventions. Conclusions: The newly created CRF enhances systematization of future work by proposing a portfolio of measures that should be collected in the development and implementation of studies assessing novel interventions intended to increase the level of consciousness or rate of recovery of consciousness in patients with disorders of consciousness. [ABSTRACT FROM AUTHOR]

Background: The implementation of multimodality monitoring in the clinical management of patients with disorders of consciousness (DoC) results in physiological measurements that can be collected in a continuous and regular fashion or even at waveform resolution. Such data are considered part of the "Big Data" available in intensive care units and are potentially suitable for health care-focused artificial intelligence research. Despite the richness in content of the physiological measurements, and the clinical implications shown by derived metrics based on those measurements, they have been largely neglected from previous attempts in harmonizing data collection and standardizing reporting of results as part of common data elements (CDEs) efforts. CDEs aim to provide a framework for unifying data in clinical research and help in implementing a systematic approach that can facilitate reliable comparison of results from clinical studies in DoC as well in international research collaborations. Methods: To address this need, the Neurocritical Care Society's Curing Coma Campaign convened a multidisciplinary panel of DoC "Physiology and Big Data" experts to propose CDEs for data collection and reporting in this field. Results: We report the recommendations of this CDE development panel and disseminate CDEs to be used in physiologic and big data studies of patients with DoC. Conclusions: These CDEs will support progress in the field of DoC physiologic and big data and facilitate international collaboration. [ABSTRACT FROM AUTHOR]

The convergence of an interdisciplinary team of neurocritical care specialists to organize the Curing Coma Campaign is the first effort of its kind to coordinate national and international research efforts aimed at a deeper understanding of disorders of consciousness (DoC). This process of understanding includes translational research from bench to bedside, descriptions of systems of care delivery, diagnosis, treatment, rehabilitation, and ethical frameworks. The description and measurement of varying confounding factors related to hospital care was thought to be critical in furthering meaningful research in patients with DoC. Interdisciplinary hospital care is inherently varied across geographical areas as well as community and academic medical centers. Access to monitoring technologies, specialist consultation (medical, nursing, pharmacy, respiratory, and rehabilitation), staffing resources, specialty intensive and acute care units, specialty medications and specific surgical, diagnostic and interventional procedures, and imaging is variable, and the impact on patient outcome in terms of DoC is largely unknown. The heterogeneity of causes in DoC is the source of some expected variability in care and treatment of patients, which necessitated the development of a common nomenclature and set of data elements for meaningful measurement across studies. Guideline adherence in hemorrhagic stroke and severe traumatic brain injury may also be variable due to moderate or low levels of evidence for many recommendations. This article outlines the process of the development of common data elements for hospital course, confounders, and medications to streamline definitions and variables to collect for clinical studies of DoC. [ABSTRACT FROM AUTHOR]

Background: Over the past 5 decades, advances in neuroimaging have yielded insights into the pathophysiologic mechanisms that cause disorders of consciousness (DoC) in patients with severe brain injuries. Structural, functional, metabolic, and perfusion imaging studies have revealed specific neuroanatomic regions, such as the brainstem tegmentum, thalamus, posterior cingulate cortex, medial prefrontal cortex, and occipital cortex, where lesions correlate with the current or future state of consciousness. Advanced imaging modalities, such as diffusion tensor imaging, resting-state functional magnetic resonance imaging (fMRI), and task-based fMRI, have been used to improve the accuracy of diagnosis and long-term prognosis, culminating in the endorsement of fMRI for the clinical evaluation of patients with DoC in the 2018 US (task-based fMRI) and 2020 European (task-based and resting-state fMRI) guidelines. As diverse neuroimaging techniques are increasingly used for patients with DoC in research and clinical settings, the need for a standardized approach to reporting results is clear. The success of future multicenter collaborations and international trials fundamentally depends on the implementation of a shared nomenclature and infrastructure. Methods: To address this need, the Neurocritical Care Society's Curing Coma Campaign convened an international panel of DoC neuroimaging experts to propose common data elements (CDEs) for data collection and reporting in this field. Results: We report the recommendations of this CDE development panel and disseminate CDEs to be used in neuroimaging studies of patients with DoC. Conclusions: These CDEs will support progress in the field of DoC neuroimaging and facilitate international collaboration. [ABSTRACT FROM AUTHOR]

Robert-Edan and Lakhal for their kind words [[1]] regarding our article on practice guidance for hemodynamic management in the prevention of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage [[2]]. This article is related to the Letter to the editor available at https://link.springer.com/article/10.1007/s12028-023-01789-z. 2 Deem S, Diringer M, Livesay S, Treggiari MM. Hemodynamic management in the prevention and treatment of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage. [Extracted from the article]

One of the most serious complications after subarachnoid hemorrhage (SAH) is delayed cerebral ischemia, the cause of which is multifactorial. Delayed cerebral ischemia considerably worsens neurological outcome and increases the risk of death. The targets of hemodynamic management of SAH have widely changed over the past 30 years. Hypovolemia and hypotension were favored prior to the era of early aneurysmal surgery but were subsequently replaced by the use of hypervolemia and hypertension. More recently, the concept of goal-directed therapy targeting euvolemia, with or without hypertension, is gaining preference. Despite the evolving concepts and the vast literature, fundamental questions related to hemodynamic optimization and its effects on cerebral perfusion and patient outcomes remain unanswered. In this review, we explain the rationale underlying the approaches to hemodynamic management and provide guidance on contemporary strategies related to fluid administration and blood pressure and cardiac output manipulation in the management of SAH. [ABSTRACT FROM AUTHOR]

Background: The neurointensive care management of patients with aneurysmal subarachnoid hemorrhage (aSAH) is one of the most critical components contributing to short-term and long-term patient outcomes. Previous recommendations for the medical management of aSAH comprehensively summarized the evidence based on consensus conference held in 2011. In this report, we provide updated recommendations based on appraisal of the literature using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Methods: The Population/Intervention/Comparator/Outcome (PICO) questions relevant to the medical management of aSAH were prioritized by consensus from the panel members. The panel used a custom-designed survey instrument to prioritize clinically relevant outcomes specific to each PICO question. To be included, the study design qualifying criteria were as follows: prospective randomized controlled trials (RCTs), prospective or retrospective observational studies, case–control studies, case series with a sample larger than 20 patients, meta-analyses, restricted to human study participants. Panel members first screened titles and abstracts, and subsequently full text review of selected reports. Data were abstracted in duplicate from reports meeting inclusion criteria. Panelists used the Grading of Recommendations Assessment, Development, and Evaluation Risk of Bias tool for assessment of RCTs and the "Risk of Bias In Nonrandomized Studies – of Interventions" tool for assessment of observational studies. The summary of the evidence for each PICO was presented to the full panel, and then the panel voted on the recommendations. Results: The initial search retrieved 15,107 unique publications, and 74 were included for data abstraction. Several RCTs were conducted to test pharmacological interventions, and we found that the quality of evidence for nonpharmacological questions was consistently poor. Five PICO questions were supported by strong recommendations, one PICO question was supported by conditional recommendations, and six PICO questions did not have sufficient evidence to provide a recommendation. Conclusions: These guidelines provide recommendations for or against interventions proven to be effective, ineffective, or harmful in the medical management of patients with aSAH based on a rigorous review of the available literature. They also serve to highlight gaps in knowledge that should guide future research priorities. Despite improvements in the outcomes of patients with aSAH over time, many important clinical questions remain unanswered. [ABSTRACT FROM AUTHOR]

Their contributions are essential to our efforts to provide high-quality publications to our readers. Peer review is the gold standard in evaluating everything from scholarly publication to grants to tenure decisions. [Extracted from the article]

This article is a preface to a special issue of Seminars in Neurology that focuses on neurocritical care. The field of neurocritical care involves the evaluation and management of life-threatening neurological and neurosurgical conditions, requiring rapid interventions to optimize outcomes. The special issue covers a range of topics, including brain death criteria, management strategies for specific conditions, advanced imaging and electrophysiology, temperature management, status epilepticus, posttraumatic epilepsy, artificial intelligence and machine learning, nursing interventions, pediatric neurocritical care, and post-intensive care syndrome. The goal of the articles is to provide clinicians, researchers, and stakeholders with up-to-date insights and developments in neurocritical care to support more informed and effective practices. [Extracted from the article]

Background: Several recent studies across the field of medicine have indicated gender disparity in the reception of prestigious awards and research grants, placing women in medicine at a distinct disadvantage. Gender disparity has been observed in neurology, critical care medicine and within various professional societies. In this study, we have examined the longitudinal trends of gender parity in awards and grants within the Neurocritical Care Society (NCS). Methods: A retrospective analysis was conducted of all available data longitudinally from 2004, when NCS first granted awards through 2019. We used self-identified gender in the membership roster to record gender for each individual. For individuals without recorded gender, we used a previously validated double verification method using a systematic web-based search. We collected data on six awards distributed by the NCS and divided these awards into two main categories: (1) scientific category: (a) Christine Wijman Young Investigator Award; (b) Best Scientific Abstract Award; (c) Fellowship Grant; (d) INCLINE Grant; and (2) non-scientific category: (a) Travel Grant; and (b) Presidential Citation. Available data were analyzed to evaluate longitudinal trends in awards using descriptive statistics and simple or multiple linear regression analyses, as appropriate. Results: A total of 445 awards were granted between the years 2004 and 2019. Thirty-six awards were in the scientific category, while 409 awards were in the non-scientific category. Only 8% of women received NCS awards in the scientific awards category, whereas 44% of women received an award in the non-scientific category. Most notable in the scientific category are the Best Scientific Abstract Award and the Fellowship Grant, in which no woman has ever received an award to date, compared to 18 men between both awards. In contrast, women are well represented in the non-scientific awards category with an average of 5% increase per year in the number of women awardees. Conclusions: Our data reveal gender disparity, mainly for scientific or research awards. Prompt evaluation of the cause and further actions to address gender disparity in NCS grants and recognition awards is needed to establish gender equity in this area. [ABSTRACT FROM AUTHOR]

Background: Several studies in critical care and neurology demonstrate women under-representation in professional societies; representation trends within the Neurocritical Care Society (NCS) are unknown. We examined longitudinal gender parity trends in membership and leadership within NCS. Methods: A retrospective study of NCS membership and leadership rosters was conducted. To determine gender, self-reported binary gender was extracted. For individuals without recorded gender, a systematic Web-based search to identify usage of gender-specific pronouns in publicly available biographies was performed. According to previously published methods, available photographs were utilized to record presumed gender identification in the absence of available pronoun descriptors. We analyzed available data longitudinally from 2002 to 2019 and performed descriptive statistical and linear regression analyses. Results: In overall membership, the proportion of women members demonstrated an average 11% increase between 2005 and 2018 (95% confidence interval (CI) − 8.1 to 30.1, p = 0.08). The proportion of women Board of Directors (BOD) members increased significantly over time to 50% in 2019. There was an increase in women Officers from 0% in the first 3 years (2002–2004) to 40% in 2019, with two women Presidents out of 17 from 2002 to 2019. For available Executive Committee rosters, there was a statistically significant nearly 3% increase per year (95% CI 1.5–4; p = 0.0007) in the proportion of women members. Rosters for Committee members and chairpersons were also incomplete, but in an analysis of the available data, there was a statistically significant increase of 5% per year analyzed (95% CI 0.5–9.7; p = 0.04) in the proportion of women Committee members. We also found a statistically significant 4.3% increase per year analyzed (95% CI 2.4–6.1; p = 0.003) in the proportion of women Committee chairpersons. Conclusions: This is the first study of longitudinal gender parity trends within neurocritical care. We report that from 2002 to 2019, the NCS has undergone a significant increase in women representation in general membership, committee membership, and leadership positions. [ABSTRACT FROM AUTHOR]

Peer review is the gold standard in evaluating everything from scholarly publication to grants to tenure decisions. Their contributions are essential to our efforts to provide high-quality publications to our readers. [Extracted from the article]

The Neurocritical Care Society and the Society of Critical Care Medicine have worked together to create a perspective regarding the Standards of Neurologic Critical Care Units (Moheet et al. in Neurocrit Care 29:145-160, 2018). The most neurologically ill or injured patients warrant the highest standard of care available; this supports the need for defining and establishing specialized neurological critical care units. Rather than interpreting the Standards as being exclusionary, it is most appropriate to embrace them in the setting of team-based care. Since there are many more patients than there are highly specialized beds, collaborative care and appropriate transfer agreements are essential in promoting excellent patient outcomes. This viewpoint addresses areas of clarification and emphasizes the need for collegiality and partnership in delivering the best specialty critical care to our patients. [ABSTRACT FROM AUTHOR]

Peer review is the gold standard in evaluating everything from scholarly publication to grants to tenure decisions. For our journal, the process can only take place through the voluntary efforts of a group of dedicated individuals. Their contributions are essential to our efforts to provide high quality publications to our readers. [Extracted from the article]

Background: Performance measures are tools to measure the quality of clinical care. To date, there is no organized set of performance measures for neurocritical care.Methods: The Neurocritical Care Society convened a multidisciplinary writing committee to develop performance measures relevant to neurocritical care delivery in the inpatient setting. A formal methodology was used that included systematic review of the medical literature for 13 major neurocritical care conditions, extraction of high-level recommendations from clinical practice guidelines, and development of a measurement specification form.Results: A total of 50,257 citations were reviewed of which 150 contained strong recommendations deemed suitable for consideration as neurocritical care performance measures. Twenty-one measures were developed across nine different conditions and two neurocritical care processes of care.Conclusions: This is the first organized Neurocritical Care Performance Measure Set. Next steps should focus on field testing to refine measure criteria and assess implementation. [ABSTRACT FROM AUTHOR]

The Fifth Neurocritical Care Research Network (NCRN) Conference held in Boca Raton, Florida, in September of 2018 was devoted to challenging the current status quo and examining the role of the Neurocritical Care Society (NCS) in driving the science and research of neurocritical care. The aim of this in-person meeting was to set the agenda for the NCS's Neurocritical Care Research Central, which is the overall research arm of the society. Prior to the meeting, all 103 participants received educational content (book and seminar) on the 'Blue Ocean Strategy®,' a concept from the business world which aims to identify undiscovered and uncontested market space, and to brainstorm innovative ideas and methods with which to address current challenges in neurocritical care research. Three five-member working groups met at least four times by teleconference prior to the in-person meeting to prepare answers to a set of questions using the Blue Ocean Strategy concept as a platform. At the Fifth NCRN Conference, these groups presented to a five-member jury and all attendees for open discussion. The jury then developed a set of recommendations for NCS to consider in order to move neurocritical care research forward. We have summarized the topics discussed at the conference and put forward recommendations for the future direction of the NCRN and neurocritical care research in general. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Common Data Elements for Disorders of Consciousness: Recommendations from the Working Group on Behavioral Phenotyping" published in the journal Neurocritical Care. The correction adds the middle initial "G" to the name of one of the authors, Yelena Bodien. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. The article includes a long list of authors who contributed to the research. [Extracted from the article]

Neurocritical care is a distinct subspecialty focusing on the optimal management of acutely ill patients with life-threatening neurologic and neurosurgical disease or with life-threatening neurologic manifestations of systemic disease. Care by expert healthcare providers to optimize neurologic recovery is necessary. Given the lack of an organizational framework and criteria for the development and maintenance of neurological critical care units (NCCUs), this document is put forth by the Neurocritical Care Society (NCS). Recommended organizational structure, personnel and processes necessary to develop a successful neurocritical care program are outlined. Methods: Under the direction of NCS Executive Leadership, a multidisciplinary writing group of NCS members was formed. After an iterative process, a framework was proposed and approved by members of the writing group. A draft was then written, which was reviewed by the NCS Quality Committee and NCS Guidelines Committee, members at large, and posted for public comment. Feedback was formally collated, reviewed and incorporated into the final document which was subsequently approved by the NCS Board of Directors. [ABSTRACT FROM AUTHOR]

Background: Cerebral perfusion pressure (CPP) is a key parameter in management of brain injury with suspected impaired cerebral autoregulation. CPP is calculated by subtracting intracranial pressure (ICP) from mean arterial pressure (MAP). Despite consensus on importance of CPP monitoring, substantial variations exist on anatomical reference points used to measure arterial MAP when calculating CPP. This study aimed to identify differences in CPP values based on measurement location when using phlebostatic axis (PA) or tragus (Tg) as anatomical reference points. The secondary study aim was to determine impact of differences on patient outcomes at discharge.Methods: This was a prospective, repeated measures, multi-site national trial. Adult ICU patients with neurological injury necessitating ICP and CPP monitoring were consecutively enrolled from seven sites. Daily MAP/ICP/CPP values were gathered with the arterial transducer at the PA, followed by the Tg as anatomical reference points.Results: A total of 136 subjects were enrolled, resulting in 324 paired observations. There were significant differences for CPP when comparing values obtained at PA and Tg reference points (p < 0.000). Differences remained significant in repeated measures model when controlling for clinical factors (mean CPP-PA = 80.77, mean CPP-Tg = 70.61, p < 0.000). When categorizing CPP as binary endpoint, 18.8% of values were identified as adequate with PA values, yet inadequate with CPP values measured at the Tg.Conclusion: Findings identify numerical differences for CPP based on anatomical reference location and highlight importance of a standard reference point for both clinical practice and future trials to limit practice variations and heterogeneity of findings. [ABSTRACT FROM AUTHOR]