Applying openEHR's Guideline Definition Language to the SITS international stroke treatment registry: a European retrospective observational study.

BACKGROUND: Interoperability standards intend to standardise health information, clinical practice guidelines intend to standardise care procedures, and patient data registries are vital for monitoring quality of care and for clinical research. This study combines all three: it uses interoperability specifications to model guideline knowledge and applies the result to registry data. METHODS: We applied the openEHR Guideline Definition Language (GDL) to data from 18,400 European patients in the Safe Implementation of Treatments in Stroke (SITS) registry to retrospectively check their compliance with European recommendations for acute stroke treatment. RESULTS: Comparing compliance rates obtained with GDL to those obtained by conventional statistical data analysis yielded a complete match, suggesting that GDL technology is reliable for guideline compliance checking. CONCLUSIONS: The successful application of a standard guideline formalism to a large patient registry dataset is an important step toward widespread implementation of computer-interpretable guidelines in clinical practice and registry-based research. Application of the methodology gave important results on the evolution of stroke care in Europe, important both for quality of care monitoring and clinical research.

Retrospective checking of compliance with practice guidelines for acute stroke care: a novel experiment using openEHR's Guideline Definition Language.

BACKGROUND: Providing scalable clinical decision support (CDS) across institutions that use different electronic health record (EHR) systems has been a challenge for medical informatics researchers. The lack of commonly shared EHR models and terminology bindings has been recognised as a major barrier to sharing CDS content among different organisations. The openEHR Guideline Definition Language (GDL) expresses CDS content based on openEHR archetypes and can support any clinical terminologies or natural languages. Our aim was to explore in an experimental setting the practicability of GDL and its underlying archetype formalism. A further aim was to report on the artefacts produced by this new technological approach in this particular experiment. We modelled and automatically executed compliance checking rules from clinical practice guidelines for acute stroke care. METHODS: We extracted rules from the European clinical practice guidelines as well as from treatment contraindications for acute stroke care and represented them using GDL. Then we executed the rules retrospectively on 49 mock patient cases to check the cases' compliance with the guidelines, and manually validated the execution results. We used openEHR archetypes, GDL rules, the openEHR reference information model, reference terminologies and the Data Archetype Definition Language. We utilised the open-sourced GDL Editor for authoring GDL rules, the international archetype repository for reusing archetypes, the open-sourced Ocean Archetype Editor for authoring or modifying archetypes and the CDS Workbench for executing GDL rules on patient data. RESULTS: We successfully represented clinical rules about 14 out of 19 contraindications for thrombolysis and other aspects of acute stroke care with 80 GDL rules. These rules are based on 14 reused international archetypes (one of which was modified), 2 newly created archetypes and 51 terminology bindings (to three terminologies). Our manual compliance checks for 49 mock patients were a complete match versus the automated compliance results. CONCLUSIONS: Shareable guideline knowledge for use in automated retrospective checking of guideline compliance may be achievable using GDL. Whether the same GDL rules can be used for at-the-point-of-care CDS remains unknown.

OpenEHR-based representation of guideline compliance data through the example of stroke clinical practice guidelines.

In light of the lack of integration between electronic health records and decision support, this research explores how semantic electronic health record technology, particularly openEHR, can be used to represent clinical practice guidelines (CPGs). We used the tool Visual Understanding Environment (VUE) to build a graphical representation of the European ischaemic stroke clinical management guidelines. We used openEHR archetypes to conceptually support this process and also to represent clinical concepts in stroke treatment compliance criteria. Our results show that, as an intermediate step in authoring computer-interpretable guidelines, an openEHR-based representation of CPGs and their compliance criteria supports the process of identifying the relevant knowledge and data elements in the care process to be modelled. It further eases the separation of the CPGs into data and logic components and is useful as a communication means for guideline verification by clinicians. Additionally, we retrieved existing and authored new openEHR archetypes for the acute stroke clinical management process. We conclude that openEHR-based guideline and compliance data representations may be a promising first step in building future decision support applications that are well connected to the electronic health record, can be useful in locating discrepancies between different sets of guidelines within the same care context and provide a helpful tool for driving the archetype authoring and review process.

Intima-Media Thickness and Pulsatility Index of Common Carotid Arteries in Acute Ischaemic Stroke Patients with Diabetes Mellitus.

Ultrasonographic parameters such as the common carotid artery (CCA) pulsatility index (PI) and CCA intima-media thickness (IMT) have been associated with an increased mortality and risk of recurrent stroke, respectively. We hypothesized that these ultrasonographic parameters may be useful for monitoring diabetic patients after an acute stroke. We analysed retrospective data of consecutive acute ischaemic stroke patients from the ASTRAL registry who underwent pre-cerebral ultrasonographic evaluation within 7 days of symptom onset. We compared clinical, demographic, radiological and ultrasonographic parameters in diabetic versus non-diabetic patients (univariable and multivariable analyses) and the association of these parameters with CCA PI and CCA IMT. We analysed 1507 carotid duplex ultrasound examinations from patients with a median age of 74 years. Cardiovascular co-morbidities, including hypertension, hypercholesterolemia, obstructive sleep apnoea syndrome, higher body-mass index (BMI) and peripheral artery disease, were associated with diabetes mellitus (DM). Diabetics were more often under antiplatelet therapy and had atrial fibrillation at admission. Diabetic patients showed an increased CCA PI and IMT in line with more atherosclerotic changes on acute CTA compared to non-diabetic patients. Taking IMT as the dependent variable in a second analysis, DM, higher age, hypertension, smoking and CCA PI were associated with higher IMT. Taking CCA PI as the dependent variable in a third analysis, DM, higher age and higher NIHSS at admission were associated with higher CCA PI values. Increased IMT was also associated with higher PI. We show that CCA PI and IMT are higher in diabetic patients in the first week after an initial stroke.

Changes in European Label and Guideline Adherence After Updated Recommendations for Stroke Thrombolysis: Results From the Safe Implementation of Treatments in Stroke Registry.

BACKGROUND: Intravenous thrombolysis (IVT) for acute ischemic stroke is subject to label and guideline contraindications. Updated European guidelines in 2008/2009 recommended IVT in selected patients aged >80 years and stroke onset-to-treatment time 3 to 4.5 hours, which the label still prohibited. Our aim was to compare contraindication nonadherence before and after the guideline update. METHODS AND RESULTS: Data on IVT-treated patients with stroke at 232 European hospitals participating in the Safe Implementation of Treatments in Stroke registry during both periods 2006 to 2007 (n=6354) and 2010 to 2011 (n=12 046). After the 2008/2009 guideline update, the proportion of patients nonadherent to label increased from 23.6% to 51.1% (P<0.001). Specifically, nonadherence to onset-to-treatment time >3 hours increased from 8.2% to 27.9% and IVT in patients aged >80 years from 8.9% to 17.2% (both P<0.001). Nonadherence also increased to the contraindications severe stroke (National Institutes of Health Stroke Scale score >25), onset-to-treatment time >4.5 hours, blood pressure >185/110 mm Hg, and ongoing oral anticoagulation (all P≤0.001). Higher hospital IVT patient volumes were associated with higher nonadherence rates. CONCLUSIONS: After the European guideline update, new recommendations were promptly adopted and nonadherence to the unchanged label increased. Label contraindications should be updated.