OPTIma: simplifying calorimetry for proton computed tomography in high proton flux environments

Objective.Proton computed tomography (pCT) offers a potential route to reducing range uncertainties for proton therapy treatment planning, however the current trend towards high current spot scanning treatment systems leads to high proton fluxes which are challenging for existing systems. Here we demonstrate a novel approach to energy reconstruction, referred to as 'de-averaging', which allows individual proton energies to be recovered using only a measurement of their integrated energy without the need for spatial information from the calorimeter.Approach.The method is evaluated in the context of the Optimising Proton Therapy through Imaging (OPTIma) system which uses a simple, relatively inexpensive, scintillator-based calorimeter that reports only the integrated energy deposited by all protons within a cyclotron period, alongside a silicon strip based tracking system capable of reconstructing individual protons in a high flux environment. GEANT4 simulations have been performed to examine the performance of such a system at a modern commercial cyclotron facility using aσ≈ 10 mm beam for currents in the range 10-50 pA at the nozzle.Main results.Apart from low-density lung tissue, a discrepancy of less than 1% on the Relative Stopping Power is found for all other considered tissues when embedded within a 150 mm spherical Perspex phantom in the 10-30 pA current range, and for some tissues even up to 50 pA.Significance.By removing the need for the calorimeter system to provide spatial information, it is hoped that the de-averaging approach can facilitate clinically relevant, cost effective and less complex calorimeter systems for performing high current pCTs.

Implementation of a clinical trial recruitment support system based on fast healthcare interoperability resources (FHIR) in a cardiology department

Background

Clinical Trial Recruitment Support Systems can booster patient inclusion of clinical trials by automatically analyzing eligibility criteria based on electronic health records. However, missing interoperability has hindered introduction of those systems on a broader scale.

Purpose

Our aim was to develop a recruitment support system based on FHIR R4 and evaluate its usage and features in a cardiology department.

Methods/Implementation

Clinical conditions, anamnesis, examinations, allergies, medication, laboratory data and echocardiography results were imported as FHIR resources. Trial study nurses and physicians were enabled to add new and edit trial information and input inclusion and exclusion criteria using a web-browser user interface in the hospital intranet. All information were recorded on the server side as the FHIR resources “ResearchStudy” and “Group”. Eligibility criteria linked by the logical operation “OR” were represented by using multiple FHIR Group resources for enrollment. On the client side, eligibility criteria were transformed to a tree-like structure (see Figure 1). Upon user demand, all hospitalized and ambulatory patients in the cardiology department were instantly screened for trial eligibility using the FHIR eligibility criteria on the existing patients' FHIR resources. Furthermore, study personal was able to manually edit trial status (i.e. ineligible, on-study, ...) of patients, which was implemented using the FHIR resource “ResearchSubject”.

Results

This implementation of a CTRSS based on FHIR R4 was evaluated in clinical practice: Beginning from 1st April 2021 the application was used as an additional patient screening tool for the four trials CLOSURE-AF, FAIR-HF2, SPRIRIT-HF and TORCH-PLUS of the German Centre for Cardiovascular Research. As the COVID-19 pandemic is prohibiting any proper comparison of patient inclusion rates, efficacy of the recruitment support system was tested by comparing the numbers of patients identified by the recruitment support system and enrolled in a trial to the actual number of enrolled patients irrespective of the screening method from 1st April 2021 to 23rd November 2021. The system was able to identify 52 of 55 patients included in those four clinical trials.

Conclusion

Use of FHIR for defining eligibility criteria of clinical trials may facilitate interoperability and allow automatic screening for eligible patients at multiple sites of different healthcare providers in the future. Upcoming changes in FHIR should allow easier description of “OR”-linked eligibility criteria.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft

A propensity-score matched analysis of ventral-TAPP vs. laparoscopic IPOM for small and mid-sized ventral hernias. Comparison of perioperative data, surgical outcome and cost-effectiveness

PURPOSE

Laparoscopic techniques have been used and refined in hernia surgery for several years. The aim of this study was to compare an established method such as laparoscopic intra-peritoneal onlay mesh repair (lap. IPOM) with ventral Transabdominal Preperitoneal Patch Plasty (ventral-TAPP) in abdominal wall hernia repair.

METHODS

Patient-related data of 180 laparoscopic ventral hernia repairs between June 2014 and August 2020 were extracted from our prospectively maintained database. Of these patients, 34 underwent ventral-TAPP and 146 lap. IPOM. After excluding hernias with a defect size > 5 cm and obtaining balanced groups with propensity-score matching, a comparative analysis was performed in terms perioperative data, surgical outcomes and cost-effectiveness.

RESULTS

Propensity-score matching suggested 27 patients in each of the two cohorts. The statistical evaluation showed that intake of opiates was significantly higher in the lap. IPOM group compared to ventral-TAPP patients (p = 0.001). The Visual Analogue Scale (VAS) score after lap. IPOM repair was significantly higher at movement (p = 0.008) and at rest (p = 0.023). Also, maximum subjective pain during hospital stay was significantly higher in the lap. IPOM group compared to ventral-TAPP patients (p = 0.004). No hernia recurrence was detected in either group. The material costs of ventral-TAPP procedure (34.37 ± 0.47 €) were significantly lower than those of the lap. IPOM group (742.57 ± 128.44 € p = 0.001). The mean operation time was 65.19 ± 26.43 min in the lap. IPOM group and 58.65 ± 18.43 min in the ventral-TAPP cohort. Additionally, the length of hospital stay in the lap. IPOM cohort was significantly longer (p = 0.043).

CONCLUSION

Ventral-TAPP procedures represent an alternative technique to lap. IPOM repair to reduce the risk of complications related to intra-peritoneal position of mesh and fixating devices. In addition, our study showed that postoperative pain level, material costs and hospital stay of the ventral-TAPP cohort are significantly lower compared to lap. IPOM patients.

Diagnosing ventilator-associated pneumonia (VAP) in UK NHS ICUs: the perceived value and role of a novel optical technology

BACKGROUND

Diagnosing ventilator-associated pneumonia (VAP) in an intensive care unit (ICU) is a complex process. Our aim was to collect, evaluate and represent the information relating to current clinical practice for the diagnosis of VAP in UK NHS ICUs, and to explore the potential value and role of a novel diagnostic for VAP, which uses optical molecular alveoscopy to visualise the alveolar space.

METHODS

Qualitative study performing semi-structured interviews with clinical experts. Interviews were recorded, transcribed, and thematically analysed. A flow diagram of the VAP patient pathway was elicited and validated with the expert interviewees. Fourteen clinicians were interviewed from a range of UK NHS hospitals: 12 ICU consultants, 1 professor of respiratory medicine and 1 professor of critical care.

RESULTS

Five themes were identified, relating to [1] current practice for the diagnosis of VAP, [2] current clinical need in VAP diagnostics, [3] the potential value and role of the technology, [4] the barriers to adoption and [5] the evidence requirements for the technology, to help facilitate a successful adoption. These themes indicated that diagnosis of VAP is extremely difficult, as is the decision to stop antibiotic treatment. The analysis revealed that there is a clinical need for a diagnostic that provides an accurate and timely diagnosis of the causative pathogen, without the long delays associated with return of culture results, and which is not dangerous to the patient. It was determined that the technology would satisfy important aspects of this clinical need for diagnosing VAP (and pneumonia, more generally), but would require further evidence on safety and efficacy in the patient population to facilitate adoption.

CONCLUSIONS

Care pathway analysis performed in this study was deemed accurate and representative of current practice for diagnosing VAP in a UK ICU as determined by relevant clinical experts, and explored the value and role of a novel diagnostic, which uses optical technology, and could streamline the diagnostic pathway for VAP and other pneumonias.

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

[Digital documentation of complications in visceral surgery: possibilities and evaluation of an instrument for quality management]

Against the background of the growing economization of clinical medicine, in the last decades the topics of risk and complication management have also become more important in surgical disciplines. The standardization and reproducible documentation of outcome and complication data play a key role for valid quality control. In this article a digital system implemented at the surgical clinic of the Charité University Medicine in Berlin is analyzed with respect to its practicability for perioperative and postoperative monitoring of complications within the framework of quality assurance.

Clofazimine for Treatment of Cryptosporidiosis in Human Immunodeficiency Virus Infected Adults: An Experimental Medicine, Randomized, Double-blind, Placebo-controlled Phase 2a Trial

Background

We evaluated the efficacy, pharmacokinetics (PK), and safety of clofazimine (CFZ) in patients living with human immunodeficiency virus (HIV) with cryptosporidiosis.

Methods

We performed a randomized, double-blind, placebo-controlled study. Primary outcomes in part A were reduction in Cryptosporidium shedding, safety, and PK. Primary analysis was according to protocol (ATP). Part B of the study compared CFZ PK in matched individuals living with HIV without cryptosporidiosis.

Results

Twenty part A and 10 part B participants completed the study ATP. Almost all part A participants had high viral loads and low CD4 counts, consistent with failure of antiretroviral (ARV) therapy. At study entry, the part A CFZ group had higher Cryptosporidium shedding, total stool weight, and more diarrheal episodes compared with the placebo group. Over the inpatient period, compared with those who received placebo, the CFZ group Cryptosporidium shedding increased by 2.17 log2 Cryptosporidium per gram stool (95% upper confidence limit, 3.82), total stool weight decreased by 45.3 g (P = .37), and number of diarrheal episodes increased by 2.32 (P = .87). The most frequent solicited adverse effects were diarrhea, abdominal pain, and malaise. One placebo and 3 CFZ participants died during the study. Plasma levels of CFZ in participants with cryptosporidiosis were 2-fold lower than in part B controls.

Conclusions

Our findings do not support the efficacy of CFZ for the treatment of cryptosporidiosis in a severely immunocompromised HIV population. However, this trial demonstrates a pathway to assess the therapeutic potential of drugs for cryptosporidiosis treatment. Screening persons living with HIV for diarrhea, and especially Cryptosporidium infection, may identify those failing ARV therapy.

Clinical Trials Registration

NCT03341767.

Impact of different types of dental prostheses on oral-health-related quality of life: a prospective bicenter study of definitive and interim restorations

PURPOSE

To assess the impact of different types of dental prostheses, including definitive and interim restorations, on oral health-related quality of life (OHRQoL) before and after prosthetic treatment.

MATERIALS AND METHODS

A total of 151 patients received prosthetic treatment at one of two German departments of prosthetic dentistry. The patients' OHRQoL was assessed using the German version of the Oral Health Impact Profile (OHIP-G53) at baseline (T0) and at 1 week (T1) and 3 months (T2) after treatment. Patients were divided into 10 subgroups according to their pre- and posttreatment status. The effect of the type (no prosthesis; fixed prosthesis; removable prosthesis) and duration of wear (definitive; interim) of the restorations was evaluated. Results were analyzed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests with a significance level of P = .05.

RESULTS

The highest OHRQoL was recorded for patients with fixed restorations, as indicated by the fact that their OHIP scores were lowest. A significant improvement in OHRQoL (P ≤ .034) was observed for patients who needed prostheses and were then treated with removable or fixed restorations. The OHIP score was affected by a change in restoration type. Rehabilitation with definitive prostheses had a significant effect on posttreatment OHRQoL (P ≤ .006).

CONCLUSION

In general, prosthetic rehabilitation by use of fixed or removable prostheses resulted in an improvement in OHRQoL. The use of the same type of restoration before and after treatment had a positive effect on OHRQoL. If possible, a change of restoration type should be avoided. For patients who require permanent prostheses, the use of fixed and removable restorations is recommended. For oral rehabilitation, fixed restorations should be preferred in order to achieve best possible improvement of OHIP score.

Oral health-related impact profile of patients treated with fixed, removable, and telescopic dental prostheses in student courses-a prospective bicenter clinical trial

Objectives

To analyze the oral health-related impact profile in patients treated with three different types of dental prosthesis in student courses.

Materials and Methods

This prospective bicenter clinical trial was conducted with 151 patients being treated with fixed (n = 70), removable (n = 61), or telescopic dental prostheses (n = 20) in clinical student courses of two German universities from October 2018 to October 2019. All patients completed three standardized German versions of the Oral Health Impact Profile (OHIP-G49/53) before prosthetic treatment (T0), at control after 1 week (T1), and after 3 months (T2), divided into five dimensions: (a) appearance, (b) oral function, (c) psychosocial impact, (d) linguistic limitations, and (e) orofacial pain. Data were analyzed with Kolmogorov–Smirnov, Wilcoxon signed-rank, Kruskal–Wallis, Mann–Whitney, and Cronbach’s alpha tests.

Results

Within T0–T1 and T0–T2, greater improvements were determined for removable compared with fixed dental prostheses for the dimensions’ oral function (p ≤ 0.014), linguistic limitations (p ≤ 0.016), and appearance (p ≤ 0.003). No significant differences were found between fixed and telescopic dental prostheses (p ≥ 0.104) or between removable (partial dental prosthesis with clasps and complete dental prosthesis) and telescopic dental prostheses (p ≥ 0.100). Within T1–T2, a significant improvement in orofacial pain could be determined (p = 0.007).

Conclusions

Restorations presented an improvement in oral health-related quality of life. Removable dental prostheses showed better improvement than fixed ones in various dimensions.

Clinical relevance

Knowledge about the influence of oral health-related quality of life on the three different types of prosthesis used in student courses can be of decisive help in dental consultations.

[Lymph node management of cN0 penile cancer]

In penile cancer, lymph node metastasis is the main known prognostic factor affecting patients' survival. Early inguinal lymph node dissection or the resection of clinically occult lymph node metastases improves survival compared with removal when the metastases become clinically apparent. Micrometastatic lymph node involvement is undetectable by current imaging modalities. Nomograms based on clinical and histopathological tumor characteristics are unreliable in predicting lymph node involvement. Consequently, in penile cancer patients with clinically normal inguinal lymph nodes (cN0) and a tumor stage ≥pT1, G2 surgical lymph node exploration is recommended. Radical inguinal lymphadenectomy is no longer recommended because of its invasiveness and high complication rate. Modified lymphadenectomy and dynamic sentinel lymph node surgery allow the detection of lymph node-positive patients with sufficient certainty. Thereby, the sentinel lymph node approach offers the least invasiveness and high sensitivity. Extended inguinal lymphadenectomy is still recommended in the case of positive nodes.

Digital Optical Archiving of Medical Records in Hospital Information Systems – A Practical Approach Towards the Computer-based Patient Record?

The large number of inpatients and outpatients in university hospitals leads to high costs of medical documentation and to an increasing number of medical documents. Due to legal regulations, these medical records have to be stored for 30 years. This implies spatial, organizational, and economical problems. At present, conventional archiving in hospitals often does not satisfy the need to make medical records available for healthcare professionals in a systematic and timely manner. From 1989 to 1993 a pilot study on “digital optical archiving of medical records” was carried out at Heidelberg University Hospital. The study has shown the feasibility of digital optical archiving in hospitals if done under certain conditions. In 1995, Heidelberg University Hospital adopted a procedure for“ digital optical archiving of medical records”. The digital optical archive will first be filled with the medical records of the department of neurosurgery and the endoscopic and echographic images and reports of the department of internal medicine. It is to be expected that this procedure will gradually lead to an integrated functionality on health-care professional workstations, to a hospital-wide use of an electronic patient record, and to media-independent document management systems. The paper focusses on the potentials of digital optical archiving as an integral part of hospital information systems, and on the requirements for the systematic managements of hospital information systems with respect to digital optical archives.

A Three-Level Graph-Based Model for the Management of Hospital Information Systems

Information processing in hospitals, especially in university hospitals, is currently faced with two major issues: low-cost hardware and progress in networking technology leads to a further decentralization of computing capacity, due to the increasing need for information processing in hospitals and due to economic restrictions, it is necessary to use, commercial software products. This leads to heterogeneous hospital information systems using a variety of software and hardware products, and to a stronger demand for integrating these products and, in general, for a dedicated methodology for the management of hospital information systems to support patient care and medical research. We present a three-level graph-based model (3LGM) to support the systematic management of hospital information systems. 3LGM can serve as a basis for assessing the quality of information processing in hospitals. 3LGM distinguishes between a procedural level for describing the information procedures (and their information interchange) of a hospital information system and thus its functionality, a logical tool level, focusing on application systems and communication links, and a physical tool level with physical subsystems (e.g., computer systems) and data transmission. The examples that are presented have been taken from the Heidelberg University Hospital Information System.

Modeling Hospital Information Systems (Part 1): The Revised Three-layer Graph-based Meta Model 3LGM2

Objectives: Not only architects but also information managers need models and modeling tools for their subject of work. Especially for supporting strategic information management in hospitals, the meta model 3LGM2 is presented as an ontological basis for modeling the comprehensive information system of a hospital (HIS).

Methods: In a case study, requirements for modeling HIS have been deduced. Accordingly 3LGM2 has been designed to describe HIS by concepts on three layers. The domain layer consists of enterprise functions and entity types, the logical tool layer focuses on application components and the physical tool layer describes physical data processing components. In contrast to other approaches a lot of inter-layer-relationships exist. 3LGM2 is defined using the Unified Modeling Language (UML).

Results: Models of HIS can be created which comprise not only technical and semantic aspects but also computer-based and paper-based information processing. A software tool supporting the creation of 3LGM2 compliant models in a graphical way has been developed. The tool supports in detecting those shortcomings at the logical or the physical tool layers which make it impossible to satisfy the information needs at the domain layer. 3LGM2 can also be used as an ontology for describing HIS in natural language.

Conclusions: Strategic information management even in large hospitals should be and can be supported by dedicated methods and tools. Although there have been good experiences with 3LGM2 concerning digital document archiving at the Leipzig University Hospital, which are presented in part 2, the benefit of the proposed method and tool has to be further evaluated.

Modeling Interdependencies between Information Processes and Communication Paths in Hospitals

Objectives: For planning hospital information systems it is important to recognize the interrelation between business processes and the communication needs between supporting application systems. We therefore present an approach to model, visualize and analyze those interdependencies.

Methods: The approach is based on the concepts defined in 3LGM2, a meta-model to describe health information systems (HIS). An information process is defined as a sequence of functions using or updating information; a communication path as a sequence of communication links between interfaces belonging to application systems. The search for communication paths belonging to an information process is interpreted as an all-pairs shortest-paths problem. To solve this problem the Floyd-Warshall algorithm is applied.

Results: The resulting algorithm has been implemented as function of the 3LGM2 tool, a tool to create 3LGM2 compliant models. With it, it is possible to interactively define information processes at the domain layer and to analyze step by step whether the infrastructure at the logical tool layer is sufficient to communicate necessary data between application systems.

Conclusions: The presented approach enables the representation and analysis of dependencies between information processes and communication paths.

With it, the HIS architecture is directly associated with the business needs. This is an important condition for the systematic planning of hospital information systems.

Medical Informatics Education Needs Information System Practicums in Health Care Settings

Objectives: To report about the themes and about experiences with practicums in the management of information systems in health care settings (health information management) for medical informatics students.

Methods: We first summarize the topics of the health information management practicums/projects that the authors organized between 1990 and 2003 for the medical informatics programs at Heidelberg/ Heilbronn, Germany, UMIT, Austria, as well as for the informatics program at the University of Leipzig, Germany. Experiences and lessons learned, obtained from the faculty that organized the practicums in the past 14 years, are reported.

Results: Thirty (of 32) health information management practicums focused on the analysis of health information systems. These took place inside university medical centers. Although the practicums were time-intensive and required intensively tutoring students with regard to health information management and project management, feedback from the students and graduates was mainly positive.

Discussion: It is clearly recommended that students specializing in medical informatics need to be confronted with real-world problems of health information systems during their studies.

Modeling Hospital Information Systems (Part 2): Using the 3LGM2 Tool for Modeling Patient Record Management

Objectives: We introduce the 3LGM2 tool, a tool for modeling information systems, and describe the process of modeling parts of the hospital information system of the Leipzig University Hospital (UKLa). We modeled the sub information systems of five patient record archiving sections to support the creation of a proposal for governmental financial support for a new document management and archiving system. We explain the steps of identifying the model elements and their relations as well as the analyzing capabilities of the 3LGM2 tool to answer questions about the information system.

Methods: The 3LGM2 tool was developed on the basis of the meta model 3LGM2 which is described in detail in [1]. 3LGM2 defines an ontological basis, divided into three layers and their relationships. In addition to usual meta CASE tools, the 3LGM2 tool meets certain requirements of information management in hospitals. The model described in this article was created on the base of on-site surveys in five archiving sections of the UKL.

Results: A prototype of the 3LGM2 tool is available and is currently tested in some projects at the UKL and partner institutions. The model presented in this article is a structured documentation about the current state of patient record archiving at the UKL. The analyzing capabilities of the 3LGM2 tool help to use the model and to answer questions about the information system.

Conclusions: The 3LGM2 tool can be used to model and analyze information systems. The presentation capabilities and the reliability of the prototype have to be improved. The initial modeling effort of an institution is only valuable if the model is maintained regularly and reused in other projects. Reference catalogues and reference models are needed to decrease this effort and to support the creation of comparable models.

More than Four Decades of Medical Informatics Education for Medical Students in Germany

The publication of German competency-based learning objectives “Medical Informatics” for undergraduate medical education gives reason to report on more publications of the German journal GMS Medical Informatics, Biometry and Epidemiology ( MIBE ) in Methods. The publications in focus deal with support of medical education by health and biomedical informatics, hospital information systems and their relation to medical devices, transinstitutional health information systems and the need of national eHealth strategies, epidemiological research on predicting high consumption of resources, and with the interaction of epidemiologists and medical statisticians in examining mortality risks in diabetes, in genome wide association studies and in dealing with limits and thresholds. This report is the beginning of an annual series intending to support better international cooperation to achieve good information as a basis for good medicine and good healthcare.

Communication Architecture for AAL

Introduction: This article is part of the Focus Theme of Methods of Information in Medicine on “Using Data from Ambient Assisted Living and Smart Homes in Electronic Health Records”.

Background: Concepts of Ambient Assisted Living (AAL) support a long-term health monitoring and further medical and other services for multi-morbid patients with chronic diseases. In Germany many AAL and telemedical applications exist. Synergy effects by common agreements for essential application components and standards are not achieved.

Objectives: It is necessary to define a communication architecture which is based on common definitions of communication scenarios, application components and communication standards.

Methods: The development of a communication architecture requires different steps. To gain a reference model for the problem area different AAL and telemedicine projects were compared and relevant data elements were generalized. The derived reference model defines standardized communication links.

Results: As a result the authors present an approach towards a reference architecture for AAL-communication. The focus of the architecture lays on the communication layer. The necessary application components are identified and a communication based on standards and their extensions is highlighted.

Conclusion: The exchange of patient in -dividual events supported by an event classification model, raw and aggregated data from the personal home area over a tele-medicine center to health care providers is possible.

The Future of Medical Informatics

Objectives: Presenting the author’s point of view on chances and challenges of medical informatics in research, education, and practice of information management, especially in the field of regional as well as institutional health information systems.

Method: Collecting and interpreting current issues concerning (health) information systems and their management from selected references.

Results: There are challenging research topics concerning information management, IT service management in small health care units, reference models, trustworthy architectures, service-oriented architectures. Medical informatics requires multidisciplinarity.

Conclusions: Medicine and health care need medical informatics as a scientific, researching discipline.

Integrated Data Repository Toolkit (IDRT)

Background: In recent years, research data warehouses moved increasingly into the focus of interest of medical research. Nevertheless, there are only a few center-independent infrastructure solutions available. They aim to provide a consolidated view on medical data from various sources such as clinical trials, electronic health records, epidemiological registries or longitudinal cohorts. The i2b2 framework is a well-established solution for such repositories, but it lacks support for importing and integrating clinical data and metadata.

Objectives: The goal of this project was to develop a platform for easy integration and administration of data from heterogeneous sources, to provide capabilities for linking them to medical terminologies and to allow for transforming and mapping of data streams for user-specific views.

Methods: A suite of three tools has been developed: the i2b2 Wizard for simplifying administration of i2b2, the IDRT Import and Mapping Tool for loading clinical data from various formats like CSV, SQL, CDISC ODM or biobanks and the IDRT i2b2 Web Client Plugin for advanced export options. The Import and Mapping Tool also includes an ontology editor for rearranging and mapping patient data and structures as well as annotating clinical data with medical terminologies, primarily those used in Germany (ICD-10-GM, OPS, ICD-O, etc.).

Results: With the three tools functional, new i2b2-based research projects can be created, populated and customized to researcher’s needs in a few hours. Amalgamating data and metadata from different databases can be managed easily. With regards to data privacy a pseudonymization service can be plugged in. Using common ontologies and reference terminologies rather than project-specific ones leads to a consistent understanding of the data semantics.

Conclusions: i2b2’s promise is to enable clinical researchers to devise and test new hypothesis even without a deep knowledge in statistical programing. The approach pre -sented here has been tested in a number of scenarios with millions of observations and tens of thousands of patients. Initially mostly observant, trained researchers were able to construct new analyses on their own. Early feedback indicates that timely and extensive access to their “own” data is appreciated most, but it is also lowering the barrier for other tasks, for instance checking data quality and completeness (missing data, wrong coding).

Higgs physics at the CLIC electron-positron linear collider

The Compact Linear Collider (CLIC) is an option for a future [Formula: see text] collider operating at centre-of-mass energies up to [Formula: see text], providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: [Formula: see text], 1.4 and [Formula: see text]. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung ([Formula: see text]) and [Formula: see text]-fusion ([Formula: see text]), resulting in precise measurements of the production cross sections, the Higgs total decay width [Formula: see text], and model-independent determinations of the Higgs couplings. Operation at [Formula: see text] provides high-statistics samples of Higgs bosons produced through [Formula: see text]-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes [Formula: see text] and [Formula: see text] allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.

Acute kidney injury following primary hip and knee arthroplasty surgery

Acute kidney injury (AKI) is a recognised postoperative complication following primary hip/knee arthroplasty surgery. The aim of this study was to determine causative and potentially modifiable risk factors associated with postoperative AKI. Standard data were collected for 413 consecutive arthroplasty patients, both retrospectively and prospectively. Univariate and multivariate analyses were performed to identify any potential causative factors. Eight percent of patients developed postoperative AKI. Univariate analysis found increasing age, history of previous chronic kidney disease and requirement for postoperative intravenous fluids to be risk factors for AKI. The multivariate regression analysis model identified age and volume of postoperative fluid prescription as predictive of postoperative AKI. Antibiotic regime and prescription of non-steroidal anti-inflammatory drugs had no significant effect on the risk of AKI. No patients required dialysis but length of stay increased by 50% in the AKI group. Postoperative AKI may result in significant postoperative morbidity and increased length of stay, and may necessitate invasive therapies such as dialysis. Episodes of AKI could also predispose to future similar episodes and are associated with a long-term decrease in baseline renal function. This study has demonstrated that the identified risk factors are generally non-modifiable. Further work is suggested to determine whether targeted interventions in high risk patients would reduce the incidence of AKI.