Accessing complex patient data from Arden Syntax Medical Logic Modules.

OBJECTIVE: Arden Syntax is a standard for representing and sharing medical knowledge in form of independent modules and looks back on a history of 25 years. Its traditional field of application is the monitoring of clinical events such as generating an alert in case of occurrence of a critical laboratory result. Arden Syntax Medical Logic Modules must be able to retrieve patient data from the electronic medical record in order to enable automated decision making. For patient data with a simple structure, for instance a list of laboratory results, or, in a broader view, any patient data with a list or table structure, this mapping process is straightforward. Nevertheless, if patient data are of a complex nested structure the mapping process may become tedious. Two clinical requirements - to process complex microbiology data and to decrease the time between a critical laboratory event and its alerting by monitoring Health Level 7 (HL7) communication - have triggered the investigation of approaches for providing complex patient data from electronic medical records inside Arden Syntax Medical Logic Modules. METHODS AND MATERIALS: The data mapping capabilities of current versions of the Arden Syntax standard as well as interfaces and data mapping capabilities of three different Arden Syntax environments have been analyzed. We found and implemented three different approaches to map a test sample of complex microbiology data for 22 patients and measured their execution times and memory usage. Based on one of these approaches, we mapped entire HL7 messages onto congruent Arden Syntax objects. RESULTS: While current versions of Arden Syntax support the mapping of list and table structures, complex data structures are so far unsupported. We identified three different approaches to map complex data from electronic patient records onto Arden Syntax variables; each of these approaches successfully mapped a test sample of complex microbiology data. The first approach was implemented in Arden Syntax itself, the second one inside the interface component of one of the investigated Arden Syntax environments. The third one was based on deserialization of Extended Markup Language (XML) data. Mean execution times of the approaches to map the test sample were 497ms, 382ms, and 84ms. Peak memory usage amounted to 3MB, 3MB, and 6MB. CONCLUSION: The most promising approach by far was to map arbitrary XML structures onto congruent complex data types of Arden Syntax through deserialization. This approach is generic insofar as a data mapper based on this approach can transform any patient data provided in appropriate XML format. Therefore it could help overcome a major obstacle for integrating clinical decision support functions into clinical information systems. Theoretically, the deserialization approach would even allow mapping entire patient records onto Arden Syntax objects in one single step. We recommend extending the Arden Syntax specification with an appropriate XML data format.

An Architecture for Continuous Data Quality Monitoring in Medical Centers.

In the medical domain, data quality is very important. Since requirements and data change frequently, continuous and sustainable monitoring and improvement of data quality is necessary. Working together with managers of medical centers, we developed an architecture for a data quality monitoring system. The architecture enables domain experts to adapt the system during runtime to match their specifications using a built-in rule system. It also allows arbitrarily complex analyses to be integrated into the monitoring cycle. We evaluate our architecture by matching its components to the well-known data quality methodology TDQM.

A meta-analysis of the efficacy of laser phototherapy on pain relief.

OBJECTIVE: Laser phototherapy has been widely used to relieve pain for more than 30 years, but its efficacy remains controversial. To ascertain the overall effect of phototherapy on pain, we aggregated the literature and subjected the studies to statistical meta-analysis. METHODS: Relevant original studies were gathered from every available source and coded. Articles that met preestablished inclusion criteria were subjected to statistical meta-analysis, using Cohen's d statistic to determine treatment effect sizes. RESULTS: Fifty-two effect sizes were computed from the 22 articles that met the inclusion criteria. The resulting overall mean effect size was highly significant; d = +0.84 (95% confidence interval = 0.44-1.23). The effect size remained significant even when a high outlying d value was conservatively excluded from the analysis; d = +0.66 (95% confidence interval = 0.46-0.86). The fail-safe number associated with the overall treatment effect, that is, the number of additional studies in which phototherapy has negative or no effect on pain needed to negate the overall large effect size of +0.84, was 348. DISCUSSION: These findings warrant the conclusion that laser phototherapy effectively relieves pain of various etiologies; making it a valuable addition to contemporary pain management armamentarium.

A meta-analysis of the efficacy of phototherapy in tissue repair.

OBJECTIVE: The effect of phototherapy on tissue repair was determined by aggregating the literature and using statistical meta-analysis to analyze pertinent studies published between 2000 and 2007. BACKGROUND DATA: Phototherapy has been used for more than 40 y; however, its efficacy on tissue repair remains contentious. METHOD: Related original studies were gathered from every available source. The papers were then screened and coded; those meeting pre-established inclusion criterion were subjected to meta-analysis, using Cohen's d statistic to determine treatment effect size. RESULTS: Seventy effect sizes were computed from the 23 papers that met the inclusion criteria. The overall mean effect obtained was highly significant, d = +1.94 (95% confidence interval = 0.58-2.50). Further analyses revealed a similarly positive effect of phototherapy on tissue repair in experimental animal studies, d = +2.60, and a small to moderately positive effect in human cases of tissue repair, d = +0.34. The fail-safe number associated with the overall effect was 869; i.e., the number of additional studies in which phototherapy has negative or no effect on wound healing needed to negate the overall large effect size of + 1.94. The corresponding fail-safe numbers for experimental animal and human tissue repair studies were 612 and 64, respectively. CONCLUSION: These findings indicate that phototherapy is a highly effective form of treatment for tissue repair, with stronger supporting evidence resulting from experimental animal studies than human studies.

Instability of confined thin liquid film trilayers.

The instability of a system in which three stratified thin liquid films are confined in a channel with parallel walls and the interior film is subject to van der Waals-driven breakup is examined in this work. We derive a model based on lubrication theory and consisting of a pair of nonlinear partial differential equations describing the position of the two liquid interfaces. A linear stability analysis is carried out to show that the effects of varying the boundary film thicknesses can be understood in terms of several known limits, including a supported monolayer, confined bilayer, and supported bilayer. Variation of the boundary film viscosities is shown in many cases to eliminate the supported-bilayer limit. The parameter regimes in which squeezing and bending modes dominate the initial growth are determined, and nonlinear simulations are used to show that the mode always switches to squeezing near rupture. It is also found that a multi-modal dispersion relation may be created by asymmetries in thickness ratio, but not viscosity ratio, even in the absence of asymmetric interfacial tensions. The results of this study are expected to be relevant to multiphase microfluidic systems and the lithographic printing process.

Semantic integration in healthcare networks.

A seamless support of information flow for increasingly distributed healthcare processes requires to integrate heterogeneous IT systems into a comprehensive distributed information system. Different standards contribute to ease this integration. In a research project focussing on the development of a reference architecture for inter-institutional health information systems, we identified concurring standards currently in use. We therefore categorized these integration standards by distinguishing between technical and semantic integration on the one hand, and data and functional integration on the other hand. In addition, standards for semantic integration are roughly categorized according to their scope. By placing standards into a corresponding matrix a "semantic gap" is revealed, which cannot be covered by standards as it contains volatile medical concepts. As a conclusion, it is recommended to conceptually consider the necessity of system evolution in system architectures and also in future integration standards.

Synthesis and characterization of novel poly(ethylene glycol)-lipid conjugates suitable for use in drug delivery.

Liposomal formulations have been used to encapsulate and deliver a wide variety of therapeutic and diagnostic agents. Their circulation can be prolonged by the addition of neutral, hydrophilic polymers such as poly(ethylene glycol) (PEG) to the outer surface. An extended circulation lifetime allows them to take advantage of the enhanced permeability and retention effect (EPR), resulting in increased delivery to target sites. Incorporation of PEG also prevents aggregation and aids in the formation of uniform, small mono-disperse particles. This is often accomplished with the use of PEG-lipid conjugates, PEG molecules with a hydrophobic domain to anchor them into the liposomal bilayer upon formulation. Here we present data showing that some commonly used PEG-lipids are chemically unstable due to the presence of carboxylic ester bonds. This instability limits their utility in aqueous environments common to many liposomal preparations. To address this problem, we designed and synthesized three alternative PEG-lipids. Using SPLP (PEG-stabilized liposomal vesicles encapsulating plasmid DNA) as a model system, we investigated the properties of the novel PEG-lipids. An accelerated stability study was conducted at 37 degrees C for 42 days to confirm chemical stability and an in vivo model was used to assess the pharmacokinetics, toxicity and activity of the SPLP. We show that the novel PEG-lipids are more stable in liposomal formulation, less toxic upon systemic administration, and accordingly, are suitable replacements for the PEG-lipids described previously.

Semantic integration in healthcare networks.

A seamless support of information flow for increasingly distributed healthcare processes requires to integrate heterogeneous IT systems into a comprehensive distributed information system. Different standards contribute to ease this integration. In a research project focussing on the development of a reference architecture for inter-institutional health information systems, we identified and categorised concurring integration standards by distinguishing between technical and semantic integration on the one hand, and data and functional integration on the other hand. In addition, standards for semantic integration are roughly categorised according to their scope. By placing standards into a corresponding matrix a "semantic gap" is revealed, which cannot be covered by standards as it contains volatile medical concepts. As a conclusion, it is recommended to conceptually consider the necessity of system evolution in systems architectures and also in future integration standards.

Towards responsive IT-infrastructures--assessment of a health information system.

Marburg University Medical Center has been introducing a comprehensive health information system since 1999, using a single-vendor application framework with an integrated generator tool for the development of clinical applications. To find out if this architecture and our participative software engineering approach can be considered a step towards a responsive infrastructure, we compared the situation after the first deployment phase (basically a holistic approach) with the situation after the system was further developed and adapted to the users' needs using the generator tool approach. We collected system statistics and conducted user satisfaction surveys in 2001/02 and 2003 using standardized measurements. The survey results showed that user involvement as well as system content were judged significantly higher after the second deployment phase. Insofar, we could demonstrate the feasibility of our approach. However, definite statements concerning the superiority of the generator tool approach to other concepts are not yet possible. We will continue our assessment, and we strongly suggest further studies in other institutions introducing comparable clinical functionality.

A practical approach to process support in health information systems.

This article describes the design of a generator tool for rapid application development. The generator tool is an integral part of a healthcare information system, and newly developed applications are embedded into the healthcare information system from the very beginning. The tool-generated applications are based on a document oriented user interaction paradigm. A significant feature is the support of intra- and interdepartmental clinical processes by means of providing document flow between different user groups. For flexible storage of newly developed applications, a generic EAV-type (Entity-Attribute-Value) database schema is used. Important aspects of a consequent implementation, like database representation of structured documents, document flow, versioning, and synchronization are presented. Applications generated by this approach are in routine use in more than 200 hospitals in Germany.