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John B Holcomb,
Deborah J del Junco,
Erin E Fox,
Charles E Wade,
Mitchell J Cohen,
Martin A Schreiber,
Louis H Alarcon,
Yu Bai,
Karen J Brasel,
Eileen M Bulger,
Bryan A Cotton,
Nena Matijevic,
Peter Muskat,
John G Myers,
Herb A Phelan,
Christopher E White, Jiajie Zhang,
Mohammad H Rahbar
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ABSTRACT: To relate in-hospital mortality to early transfusion of plasma and/or platelets and to time-varying plasma:red blood cell (RBC) and platelet:RBC ratios.
Prospective cohort study documenting the timing of transfusions during active resuscitation and patient outcomes. Data were analyzed using time-dependent proportional hazards models.
Ten US level I trauma centers.
Adult trauma patients surviving for 30 minutes after admission who received a transfusion of at least 1 unit of RBCs within 6 hours of admission (n = 1245, the original study group) and at least 3 total units (of RBCs, plasma, or platelets) within 24 hours (n = 905, the analysis group).
In-hospital mortality.
Plasma:RBC and platelet:RBC ratios were not constant during the first 24 hours (P < .001 for both). In a multivariable time-dependent Cox model, increased ratios of plasma:RBCs (adjusted hazard ratio = 0.31; 95% CI, 0.16-0.58) and platelets:RBCs (adjusted hazard ratio = 0.55; 95% CI, 0.31-0.98) were independently associated with decreased 6-hour mortality, when hemorrhagic death predominated. In the first 6 hours, patients with ratios less than 1:2 were 3 to 4 times more likely to die than patients with ratios of 1:1 or higher. After 24 hours, plasma and platelet ratios were unassociated with mortality, when competing risks from nonhemorrhagic causes prevailed.
Higher plasma and platelet ratios early in resuscitation were associated with decreased mortality in patients who received transfusions of at least 3 units of blood products during the first 24 hours after admission. Among survivors at 24 hours, the subsequent risk of death by day 30 was not associated with plasma or platelet ratios.
JAMA surgery. 02/2013; 148(2):127-36.
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John B Holcomb,
Deborah J Del Junco,
Erin E Fox,
Charles E Wade,
Mitchell J Cohen,
Martin A Schreiber,
Louis H Alarcon,
Yu Bai,
Karen J Brasel,
Eileen M Bulger,
Bryan A Cotton,
Nena Matijevic,
Peter Muskat,
John G Myers,
Herb A Phelan,
Christopher E White, Jiajie Zhang,
Mohammad H Rahbar
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ABSTRACT: OBJECTIVE To relate in-hospital mortality to early transfusion of plasma and/or platelets and to time-varying plasma:red blood cell (RBC) and platelet:RBC ratios. DESIGN Prospective cohort study documenting the timing of transfusions during active resuscitation and patient outcomes. Data were analyzed using time-dependent proportional hazards models. SETTING Ten US level I trauma centers. PATIENTS Adult trauma patients surviving for 30 minutes after admission who received a transfusion of at least 1 unit of RBCs within 6 hours of admission (n = 1245, the original study group) and at least 3 total units (of RBCs, plasma, or platelets) within 24 hours (n = 905, the analysis group). MAIN OUTCOME MEASURE In-hospital mortality. RESULTS Plasma:RBC and platelet:RBC ratios were not constant during the first 24 hours (P < .001 for both). In a multivariable time-dependent Cox model, increased ratios of plasma:RBCs (adjusted hazard ratio = 0.31; 95% CI, 0.16-0.58) and platelets:RBCs (adjusted hazard ratio = 0.55; 95% CI, 0.31-0.98) were independently associated with decreased 6-hour mortality, when hemorrhagic death predominated. In the first 6 hours, patients with ratios less than 1:2 were 3 to 4 times more likely to die than patients with ratios of 1:1 or higher. After 24 hours, plasma and platelet ratios were unassociated with mortality, when competing risks from nonhemorrhagic causes prevailed. CONCLUSIONS Higher plasma and platelet ratios early in resuscitation were associated with decreased mortality in patients who received transfusions of at least 3 units of blood products during the first 24 hours after admission. Among survivors at 24 hours, the subsequent risk of death by day 30 was not associated with plasma or platelet ratios.
Archives of surgery (Chicago, Ill.: 1960) 10/2012; · 4.32 Impact Factor
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ABSTRACT: Deregulation of receptor tyrosine kinase c-Met has been reported in human cancers and is considered as an attractive target for small molecule drug discovery. In this study, a series of spiro[indoline-3, 4'-piperidine]-2-ones were designed, synthesized and evaluated as novel c-Met inhibitors. The results showed that the majority of the compounds exhibited significant inhibitory effect on c-Met with IC(50) values of 0.0147-17 μM in TR-FRET-based assay and IC(50) values of 1.56-1400 μM in cell-based assay. Furthermore, our docking experiments verified the results and explained the molecular mechanism of eminent activities to c-Met.
European journal of medicinal chemistry 02/2012; 50:370-5. · 3.27 Impact Factor
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Mohammad H Rahbar,
Erin E Fox,
Deborah J del Junco,
Bryan A Cotton,
Jeanette M Podbielski,
Nena Matijevic,
Mitchell J Cohen,
Martin A Schreiber, Jiajie Zhang,
Parsa Mirhaji,
Sarah J Duran,
Robert J Reynolds,
Ruby Benjamin-Garner,
John B Holcomb
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ABSTRACT: Early death due to hemorrhage is a major consequence of traumatic injury. Transfusion practices differ among hospitals and it is unknown which transfusion practices improve survival. This report describes the experience of the PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) Study Data Coordination Center in designing and coordinating a study to examine transfusion practices at ten Level 1 trauma centers in the US.
PROMMTT was a multisite prospective observational study of severely injured transfused trauma patients. The clinical sites collected real-time information on the timing and amounts of blood product infusions as well as colloids and crystalloids, vital signs, initial diagnostic and clinical laboratory tests, life saving interventions and other clinical care data.
Between July 2009 and October 2010, PROMMTT screened 12,561 trauma admissions and enrolled 1245 patients who received one or more blood transfusions within 6h of Emergency Department (ED) admission. A total of 297 massive transfusions were observed over the course of the study at a combined rate of 5.0 massive transfusion patients/week.
PROMMTT is the first multisite study to collect real-time prospective data on trauma patients requiring transfusion. Support from the Department of Defense and collaborative expertise from the ten participating centers helped to demonstrate the feasibility of prospective trauma transfusion studies. The observational data collected from this study will be an invaluable resource for research in trauma surgery and it will guide the design and conduct of future randomized trials.
Resuscitation 10/2011; 83(4):459-64. · 3.60 Impact Factor
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ABSTRACT: This paper presents a unified framework of EHR usability, called TURF, which is (1) a theory for describing, explaining, and predicting usability differences; (2) a method for defining, evaluating, and measuring usability objectively; (3) a process for designing built-in good usability; and (4) once fully developed, a potential principle for developing EHR usability guidelines and standards. TURF defines usability as how useful, usable, and satisfying a system is for the intended users to accomplish goals in the work domain by performing certain sequences of tasks. TURF provides a set of measures for each of the useful, usable, and satisfying dimensions of usability. TURF stands for task, user, representation, and function, which are the four components that determine the usability of an EHR system. These four components are described with theoretical descriptions along with examples of how usability is measured in several case studies. How TURF can be used to improve usability through redesign is also demonstrated in a case study. In summary, this paper states that usability can not only be defined scientifically under a coherent, unified framework, it can also be measured objectively and systematically.
Journal of Biomedical Informatics 08/2011; 44(6):1056-67. · 1.79 Impact Factor
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ABSTRACT: In critical care environments such as the emergency department (ED), many activities and decisions are not planned. In this study, we developed a new methodology for systematically studying what are these unplanned activities and decisions. This methodology expands the traditional naturalistic decision making (NDM) frameworks by explicitly identifying the role of environmental factors in decision making. We focused on decisions made by ED physicians as they transitioned between tasks. Through ethnographic data collection, we developed a taxonomy of decision types. The empirical data provide important insight to the complexity of the ED environment by highlighting adaptive behavior in this intricate milieu. Our results show that half of decisions in the ED we studied are not planned, rather decisions are opportunistic decision (34%) or influenced by interruptions or distractions (21%). What impacts these unplanned decisions have on the quality, safety, and efficiency in the ED environment are important research topics for future investigation.
Journal of Biomedical Informatics 06/2011; 44(3):469-476. · 1.79 Impact Factor
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ABSTRACT: In a distributed information search task, data representation and cognitive distribution jointly affect user search performance in terms of response time and accuracy. Guided by UFuRT (User, Function, Representation, Task), a human-centered framework, we proposed a search model and task taxonomy. The model defines its application in the context of healthcare setting. The taxonomy clarifies the legitimate operations for each type of search task of relational data. We then developed experimental prototypes of hyperlipidemia data displays. Based on the displays, we tested the search tasks performance through two experiments. The experiments are of a within-subject design with a random sample of 24 participants. The results support our hypotheses and validate the prediction of the model and task taxonomy. In this study, representation dimensions, data scales, and search task types are the main factors in determining search efficiency and effectiveness. Specifically, the more external representations provided on the interface the better search task performance of users. The results also suggest the ideal search performance occurs when the question type and its corresponding data scale representation match. The implications of the study lie in contributing to the effective design of search interface for relational data, especially laboratory results, which could be more effectively designed in electronic medical records.
Journal of Medical Systems 04/2011; 35(2):169-77. · 1.13 Impact Factor
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ABSTRACT: In many respects, the critical care workplace resembles a paradigmatic complex system: on account of the dynamic and interactive nature of collaborative clinical work, these settings are characterized by non-linear, inter-dependent and emergent activities. Developing a comprehensive understanding of the work activities in critical care settings enables the development of streamlined work practices, better clinician workflow and most importantly, helps in the avoidance of and recovery from potential errors. Sensor-based technology provides a flexible and viable way to complement human observations by providing a mechanism to capture the nuances of certain activities with greater precision and timing. In this paper, we use sensor-based technology to capture the movement and interactions of clinicians in the Trauma Center of an Emergency Department (ED). Remarkable consistency was found between sensor data and human observations in terms of clinician locations and interactions. With this validation and greater precision with sensors, ED environment was characterized in terms of (a) the degree of randomness or entropy in the environment, (b) the movement patterns of clinicians, (c) interactions with other clinicians and finally, (d) patterns of collaborative organization with team aggregation and dispersion. Based on our results, we propose three opportunities for the use of sensor technologies in critical care settings: as a mechanism for real-time monitoring and analysis for ED activities, education and training of clinicians, and perhaps most importantly, investigating the root-causes, origins and progression of errors in the ED. Lessons learned and the challenges encountered in designing and implementing the sensor technology sensor data are discussed.
Journal of Biomedical Informatics 02/2011; 44(3):441-54. · 1.79 Impact Factor
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Proceedings of the International Conference on Human Factors in Computing Systems, CHI 2011, Extended Abstracts Volume, Vancouver, BC, Canada, May 7-12, 2011; 01/2011
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ABSTRACT: Medication errors can result from administration inaccuracies at any point of care and are a major cause for concern. To develop a successful Medication Reconciliation (MR) tool, we believe it necessary to build a Work Domain Ontology (WDO) for the MR process. A WDO defines the explicit, abstract, implementation-independent description of the task by separating the task from work context, application technology, and cognitive architecture. We developed a prototype based upon the WDO and designed to adhere to standard principles of interface design. The prototype was compared to Legacy Health System's and Pre-Admission Medication List Builder MR tools via a Keystroke-Level Model analysis for three MR tasks. The analysis found the prototype requires the fewest mental operations, completes tasks in the fewest steps, and completes tasks in the least amount of time. Accordingly, we believe that developing a MR tool, based upon the WDO and user interface guidelines, improves user efficiency and reduces cognitive load.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium 01/2011; 2011:878-87.
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ABSTRACT: Medication reconciliation is a National Patient Safety Goal (NPSG) from The Joint Commission (TJC) that entails reviewing all medications a patient takes after a health care transition. Medication reconciliation is a resource-intensive, error-prone task, and the resources to accomplish it may not be routinely available. Computer-based methods have the potential to overcome these barriers. We designed and explored a rule-based medication reconciliation algorithm to accomplish this task across different healthcare transitions. We tested our algorithm on a random sample of 94 transitions from the Clinical Data Warehouse at the University of Texas Health Science Center at Houston. We found that the algorithm reconciled, on average, 23.4% of the potentially reconcilable medications. Our study did not have sufficient statistical power to establish whether the kind of transition affects reconcilability. We conclude that automated reconciliation is possible and will help accomplish the NPSG.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium 01/2011; 2011:1252-60.
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ABSTRACT: Many Electronic Health Record (EHR) systems fail to provide user-friendly interfaces due to the lack of systematic consideration of human-centered computing issues. Such interfaces can be improved to provide easy to use, easy to learn, and error-resistant EHR systems to the users.
To evaluate the usability of an EHR system and suggest areas of improvement in the user interface.
The user interface of the AHLTA (Armed Forces Health Longitudinal Technology Application) was analyzed using the Cognitive Task Analysis (CTA) method called GOMS (Goals, Operators, Methods, and Selection rules) and an associated technique called KLM (Keystroke Level Model). The GOMS method was used to evaluate the AHLTA user interface by classifying each step of a given task into Mental (Internal) or Physical (External) operators. This analysis was performed by two analysts independently and the inter-rater reliability was computed to verify the reliability of the GOMS method. Further evaluation was performed using KLM to estimate the execution time required to perform the given task through application of its standard set of operators.
The results are based on the analysis of 14 prototypical tasks performed by AHLTA users. The results show that on average a user needs to go through 106 steps to complete a task. To perform all 14 tasks, they would spend about 22 min (independent of system response time) for data entry, of which 11 min are spent on more effortful mental operators. The inter-rater reliability analysis performed for all 14 tasks was 0.8 (kappa), indicating good reliability of the method.
This paper empirically reveals and identifies the following finding related to the performance of AHLTA: (1) large number of average total steps to complete common tasks, (2) high average execution time and (3) large percentage of mental operators. The user interface can be improved by reducing (a) the total number of steps and (b) the percentage of mental effort, required for the tasks.
International Journal of Medical Informatics 07/2010; 79(7):501-6. · 2.41 Impact Factor
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Proceedings of the 9th IEEE International Conference on Cognitive Informatics, ICCI 2010, July 7-9, 2010, Beijing, China; 01/2010
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ABSTRACT: To develop and test a statistical model which correctly predicts the approval of outpatient referrals when reviewed by a specialty service based on nine discriminating variables.
Retrospective cross-sectional study.
Large public county hospital system in a southern US city.
Written documents and associated data from 500 random adult referrals made by primary care providers to various specialty services during the course of one month.
The resulting correct prediction rates obtained by the model.
The model correctly predicted 78.6% of approved referrals using all nine discriminating variables, 75.3% of approved referrals using all variables in a stepwise manner and 74.7% of approved referrals using only the referral total word count as a single discriminating variable.
Three iterations of the model correctly predicted at least 75% of the approved referrals in the validation set. A correct prediction of whether or not a referral will be approved can be made in three out of four cases.
Informatics in primary care 01/2010; 17(4):201-7.
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ABSTRACT: Medical record abstraction, a primary mode of data collection in secondary data use, is associated with high error rates. Cognitive factors have not been studied as a possible explanation for medical record abstraction errors. We employed the theory of distributed representation and representational analysis to systematically evaluate cognitive demands in medical record abstraction and the extent of external cognitive support employed in a sample of clinical research data collection forms.We show that the cognitive load required for abstraction in 61% of the sampled data elements was high, exceedingly so in 9%. Further, the data collection forms did not support external cognition for the most complex data elements. High working memory demands are a possible explanation for the association of data errors with data elements requiring abstractor interpretation, comparison, mapping or calculation. The representational analysis used here can be used to identify data elements with high cognitive demands.
AMIA Summits on Translational Science proceedings AMIA Summit on Translational Science. 01/2010; 2010:36-40.
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ABSTRACT: Increasing amounts of clinical research data are collected by manual data entry into electronic source systems and directly from research subjects. For this manual entered source data, common methods of data cleaning such as post-entry identification and resolution of discrepancies and double data entry are not feasible. However data accuracy rates achieved without these mechanisms may be higher than desired for a particular research use. We evaluated a heuristic usability method for utility as a tool to independently and prospectively identify data collection form questions associated with data errors. The method evaluated had a promising sensitivity of 64% and a specificity of 67%. The method was used as described in the literature for usability with no further adaptations or specialization for predicting data errors. We conclude that usability evaluation methodology should be further investigated for use in data quality assurance.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium 01/2010; 2010:346-50.
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ABSTRACT: Reports submitted to the Federal Food and Drug Administration (FDA) indicate that legibility of infusion pump interfaces contributes to medication errors (for example, patients have been seriously injured when nurses overinfused them after reading the number 7 as a 1). Health care has experienced an influx of medical devices with small-screen interfaces, generically described as small-screen devices. Legibility is widely acknowledged as a necessary aspect of safe operation of medical devices. Contextual analysis was used to observe conditions affecting the legibility of the screen interface of a dual-channel infusion volumetric infusion pump in a shock trauma intensive care unit (STICU).
Observations were made of registered nurses and physicians using the infusion pumps during a four-hour period.
Results from the observations indicated that there was reduced legibility of the infusion pump screen interface because of an inherently subdued light situation, reduced screen contrast, and the small font size of the lettering.
It was clear from the beginning of the observations that the screen of the infusion pump had limited legibility. In some instances, nurses attached handmade tape labels to the infusion pump to enhance and supplement the small screen. The pump was often positioned facing away from the nurses, who then had to reposition it to view the screen, contributing to interruptions in work flow and creating a potential safety hazard. A variety of strategies are recommended to ensure legibility of infusion pump interfaces and of medical-device labels. Conclusions: A more complete environmental approach is needed to determine the legibility and usefulness of microdisplay and small-screen devices in health care.
Joint Commission journal on quality and patient safety / Joint Commission Resources 05/2009; 35(4):229-35.
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ABSTRACT: It is commonly hypothesized that external representations serve as memory aids and improve task performance by means of expanding the limited capacity of working memory. However, very few studies have directly examined this memory aid hypothesis. By systematically manipulating how information is available externally versus internally in a sequential number comparison task, three experiments were designed to investigate the relation between external representations and working memory. The experimental results show that when the task requires information from both external representations and working memory, it is the interaction of information from the two sources that determines task performance. In particular, when information from the two sources does not match well, external representations hinder instead of enhance task performance. The study highlights the important role the coordination among different representations plays in distributed cognition. The general relations between external representations and working memory are discussed.
PLoS ONE 02/2009; 4(8):e6513. · 4.09 Impact Factor
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ABSTRACT: Semantic Web technologies offer a promising framework for integration of disparate biomedical data. In this paper we present the semantic information integration platform under development at the Center for Clinical and Translational Sciences (CCTS) at the University of Texas Health Science Center at Houston (UTHSC-H) as part of our Clinical and Translational Science Award (CTSA) program. We utilize the Semantic Web technologies not only for integrating, repurposing and classification of multi-source clinical data, but also to construct a distributed environment for information sharing, and collaboration online. Service Oriented Architecture (SOA) is used to modularize and distribute reusable services in a dynamic and distributed environment. Components of the semantic solution and its overall architecture are described.
BMC Bioinformatics 02/2009; 10 Suppl 2:S2. · 2.75 Impact Factor
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Human Interface and the Management of Information. Information and Interaction, Symposium on Human Interface 2009, Held as part of HCI International 2009, San Diego, CA, USA, July 19-24, 2009, Proceedings, Part II; 01/2009
