Confident interpretation of Bayesian decision tree ensembles for clinical applications

Copyright © 2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Bayesian averaging (BA) over ensembles of decision models allows evaluation of the uncertainty of decisions that is of crucial importance for safety-critical applications such as medical diagnostics. The interpretability of the ensemble can also give useful information for experts responsible for making reliable decisions. For this reason, decision trees (DTs) are attractive decision models for experts. However, BA over such models makes an ensemble of DTs uninterpretable. In this paper, we present a new approach to probabilistic interpretation of Bayesian DT ensembles. This approach is based on the quantitative evaluation of uncertainty of the DTs, and allows experts to find a DT that provides a high predictive accuracy and confident outcomes. To make the BA over DTs feasible in our experiments, we use a Markov Chain Monte Carlo technique with a reversible jump extension. The results obtained from clinical data show that in terms of predictive accuracy, the proposed method outperforms the maximum a posteriori (MAP) method that has been suggested for interpretation of DT ensembles

The Utstein template for uniform reporting of data following major trauma: A joint revision by SCANTEM, TARN, DGU-TR and RITG

<p>Abstract</p> <p>Background</p> <p>In 1999, an Utstein Template for Uniform Reporting of Data following Major Trauma was published. Few papers have since been published based on that template, reflecting a lack of international consensus on its feasibility and use. The aim of the present revision was to further develop the Utstein Template, particularly with a major reduction in the number of core data variables and the addition of more precise definitions of data variables. In addition, we wanted to define a set of inclusion and exclusion criteria that will facilitate uniform comparison of trauma cases.</p> <p>Methods</p> <p>Over a ten-month period, selected experts from major European trauma registries and organisations carried out an Utstein consensus process based on a modified nominal group technique.</p> <p>Results</p> <p>The expert panel concluded that a New Injury Severity Score > 15 should be used as a single inclusion criterion, and five exclusion criteria were also selected. Thirty-five precisely defined core data variables were agreed upon, with further division into core data for Predictive models, System Characteristic Descriptors and for Process Mapping.</p> <p>Conclusion</p> <p>Through a structured consensus process, the Utstein Template for Uniform Reporting of Data following Major Trauma has been revised. This revision will enhance national and international comparisons of trauma systems, and will form the basis for improved prediction models in trauma care.</p

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doi:10.1186/1757-7241-16

Collecting core data in severely injured patients using a consensus trauma template: an international multicentre study

Introduction: No worldwide, standardised definitions exist for documenting, reporting and comparing data from severely injured trauma patients. This study evaluated the feasibility of collecting the data variables of the international consensus-derived Utstein Trauma Template. Methods: Trauma centres from three different continents were invited to submit Utstein Trauma Template core data during a defined period, for up to 50 consecutive trauma patients. Directly admitted patients with a New Injury Severity Score (NISS) equal to or above 16 were included. Main outcome variables were data completeness, data differences and data collection difficulty. Results: Centres from Europe (n = 20), North America (n = 3) and Australia (n = 1) submitted data on 965 patients, of whom 783 were included. Median age was 41 years (interquartile range (IQR) 24 to 60), and 73.1% were male. Median NISS was 27 (IQR 20 to 38), and blunt trauma predominated (91.1%). Of the 36 Utstein variables, 13 (36%) were collected by all participating centres. Eleven (46%) centres applied definitions of the survival outcome variable that were different from those of the template. Seventeen (71%) centres used the recommended version of the Abbreviated Injury Scale (AIS). Three variables (age, gender and AIS) were documented in all patients. Completeness > 80% was achieved for 28 variables, and 20 variables were > 90% complete. Conclusions: The Utstein Template was feasible across international trauma centres for the majority of its data variables, with the exception of certain physiological and time variables. Major differences were found in the definition of survival and in AIS coding. The current results give a clear indication of the attainability of information and may serve as a stepping-stone towards creation of a European trauma registry

Trauma care and capture rate of variables of World Health Organisation data set for injury at regional hospitals in Tanzania: first steps to a national trauma registry

Background In Tanzania, there is no national trauma registry. The World Health Organization (WHO) has developed a data set for injury that specifies the variables necessary for documenting the burden of injury and patient-related clinical processes. As a first step in developing and implementing a national Trauma Registry, we determined how well hospitals currently capture the variables that are specified in the WHO injury set. Methods This was a prospective, observational cross-sectional study of all trauma patients conducted in the Emergency Units of five regional referral hospitals in Tanzania from February 2018 to July 2018. Research assistants observed the provision of clinical care in the EU for all patients, and documented performed assessment, clinical interventions and final disposition. Research assistants used a purposefully designed case report form to audit the injury variable capture rate, and to review Ministry of Health (MoH) issued facility Register book recording the documentation of variables. We present descriptive statistics for hospital characteristics, patient volume, facility infrastructure, and capture rate of trauma variables. Results During the study period, 2891 (9.3%) patients presented with trauma-related complaints, 70.7% were male. Overall, the capture rate of all variables was 33.6%. Documentation was most complete for demographics 71.6%, while initial clinical condition, and details of injury were documented in 20.5 and 20.8% respectively. There was no documentation for the care prior to Emergency Unit arrival in all hospitals. 1430 (49.5%) of all trauma-related visits seen were documented in the facility Health Management Information System register submitted to the MoH. Among the cases reported in the register book, the date of EU care was correctly documented in 77% cases, age 43.6%, diagnosis 66.7%, and outcome in 38.9% cases. Among the observed procedures, initial clinical condition (28.7%), interventions at Emergency Unit (52.1%), investigations (49.0%), and disposition (62.9%) were documented in the clinical charts. Conclusions In the regional hospitals of Tanzania, there is inadequate documentation of the minimum trauma variables specified in the WHO injury data set. Reasons for this are unclear, but will need to be addressed in order to improve documentation to inform a national injury registry

Perceptions of health providers towards the use of standardised trauma form in managing trauma patients: a qualitative study from Tanzania

Background Trauma registries (TRs) are essential to informing the quality of trauma care within health systems. Lack of standardised trauma documentation is a major cause of inconsistent and poor availability of trauma data in most low- and middle-income countries (LMICs), hindering the development of TRs in these regions. We explored health providers’ perceptions on the use of a standardised trauma form to record trauma patient information in Tanzania. Methods An exploratory qualitative research using a semi-structured interview guide was carried out to purposefully selected key informants comprising of healthcare providers working in Emergency Units and surgical disciplines in five regional hospitals in Tanzania. Data were analysed using a thematic analysis approach to identify key themes surrounding potential implementation of the standardised trauma form. Results Thirty-three healthcare providers participated, the majority of whom had no experience in the use of standardised charting. Only five respondents had prior experience with trauma forms. Responses fell into three themes: perspectives on the concept of a standardised trauma form, potential benefits of a trauma form, and concerns regarding successful and sustainable implementation. Conclusion Findings of this study revealed wide healthcare provider acceptance of moving towards standardised clinical documentation for trauma patients. Successful implementation likely depends on the perceived benefits of using a trauma form as a tool to guide clinical management, standardise care and standardise data reporting; however, it will be important moving forward to factor concerns brought up in this study. Potential barriers to successful and sustainable implementation of the form, including the need for training and tailoring of form to match existing resources and knowledge of providers, must be considered

Correction: Management of bleeding following major trauma: a European guideline

SCOPUS: er.jinfo:eu-repo/semantics/publishe

Trial of early, goal-directed resuscitation for septic shock.

BACKGROUND: Early, goal-directed therapy (EGDT) is recommended in international guidelines for the resuscitation of patients presenting with early septic shock. However, adoption has been limited, and uncertainty about its effectiveness remains. METHODS: We conducted a pragmatic randomized trial with an integrated cost-effectiveness analysis in 56 hospitals in England. Patients were randomly assigned to receive either EGDT (a 6-hour resuscitation protocol) or usual care. The primary clinical outcome was all-cause mortality at 90 days. RESULTS: We enrolled 1260 patients, with 630 assigned to EGDT and 630 to usual care. By 90 days, 184 of 623 patients (29.5%) in the EGDT group and 181 of 620 patients (29.2%) in the usual-care group had died (relative risk in the EGDT group, 1.01; 95% confidence interval [CI], 0.85 to 1.20; P=0.90), for an absolute risk reduction in the EGDT group of -0.3 percentage points (95% CI, -5.4 to 4.7). Increased treatment intensity in the EGDT group was indicated by increased use of intravenous fluids, vasoactive drugs, and red-cell transfusions and reflected by significantly worse organ-failure scores, more days receiving advanced cardiovascular support, and longer stays in the intensive care unit. There were no significant differences in any other secondary outcomes, including health-related quality of life, or in rates of serious adverse events. On average, EGDT increased costs, and the probability that it was cost-effective was below 20%. CONCLUSIONS: In patients with septic shock who were identified early and received intravenous antibiotics and adequate fluid resuscitation, hemodynamic management according to a strict EGDT protocol did not lead to an improvement in outcome. (Funded by the United Kingdom National Institute for Health Research Health Technology Assessment Programme; ProMISe Current Controlled Trials number, ISRCTN36307479.)