Thomas Wrba

Extraction of standardized archetyped data from Electronic Health Record systems based on the Entity-Attribute-Value Model.

OBJECTIVE The ISO/EN 13606 Electronic Health Record architecture standard permits semantically interoperable exchange of Electronic Health Record data by using archetypes to define the structure and semantics of Electronic Health Record contents. Practical implementations of the ISO/EN 13606 standard have been scarcely reported on, and none of the publications describes in detail an efficient technique of archetype-compliant data extraction from an Electronic Health Record system. We address this research issue in the present report, and focus on a specific class of largely research-oriented Electronic Health Record systems which are internally based on the Entity-Attribute-Value Model. METHOD We propose an approach for extracting data described by archetypes from an Entity-Attribute-Value based Electronic Health Record system in an ISO/EN 13606-conformant manner. The approach is based on mapping from the structure of exported source documents to the archetype. It is implemented via standard XML technologies. RESULTS We tested our approach on an Electronic Health Record system employed for clinical research at the Medical University of Vienna. Using test data defined by three different archetypes, source documents were successfully extracted as archetype-conformant ISO/EN 13606 Electronic Health Record extracts. CONCLUSIONS Electronic Health Record data may be effectively extracted from Entity-Attribute-Value based Electronic Health Record systems using the suggested approach. As a prerequisite for applying our approach, the internal data model of the Electronic Health Record system and the archetype must overlap in a way that a semantic mapping between them is possible. The system must further provide an XML interface which permits the export of the source documents in conventional format. The export must include data and metadata that are mandatorily postulated by the archetype and the ISO/EN 13606 Reference Model.

A national point prevalence study on healthcare-associated infections and antimicrobial use in Austria

SummaryBackgroundThe first point prevalence survey performed in Austria had the aim to assess the magnitude of healthcare-associated infections and antimicrobials use in the country.MethodsA multicentre study was carried out from May until June 2012 in nine acute care hospitals with a mean bed number of 620. Data from 4321 patients’ clinical charts were reviewed.ResultsThe overall healthcare-associated infections prevalence was 6.2 % (268/4321) with the highest rate in intensive care departments (20.9 %; 49/234). In medical and surgical departments the healthcare-associated infections prevalence was 5.4 % (95/1745) and 6.6 % (105/1586), respectively. The most frequent healthcare-associated infections were: urinary tract infections (21.3 %; 61/287), pneumonia (20.6 %; 59/287) and surgical site infections (17.4 %; 50/287). The most common isolated microorganisms were: Escherichia coli (14.8 %; 26/176), Enterococcus species (13.1 %; 23/176) and Pseudomonas aeruginosa (11.4 %; 20/176). Thirty-three per cent (1425/4321) of the patients received antimicrobials because of community-acquired infections treatment (14.2 %; 615/4321), healthcare-associated infections treatment (6.4 %; 278/4321), and surgical (8.2 %; 354/4321) and medical prophylaxis (3.2 %; 138/4321). Surgical prophylaxis was the indication for 22.0 % (394/1792) of the overall prescriptions and was prolonged for more than 1 day in 77.2 % (304/394) of the cases.ConclusionThe national Austrian survey proved the feasibility of a nation-wide network of surveillance of both healthcare-associated infections and antimicrobial use that will be repeated in the future. Healthcare-associated infections and antimicrobial use have been confirmed to be a grave health problem. The excessive prolongation of perioperative prophylaxis in Austria needs to be limited.

Non-linear significant relationship between use of glycopeptides and isolation of vancomycin-resistant Enterococcus species in a university hospital setting

BackgroundEmergence of colonization and infection with vancomycin-resistant enterococci (VRE) has become a worldwide challenge. To investigate whether the increasing incidence of VRE isolation can be correlated with use of glycopeptides in the hospital setting, we conducted a hospital-wide two-year study in the university hospital of Vienna.MethodsWithin the period from January 2011 through December 2012 all patients with isolation of invasive or non-invasive VRE were retrospectively included. Specialty-specific data concerning the consumption of vancomycin and teicoplanin, fluoroquinolones and third generation cephalosporins in defined daily doses (DDDs) from June 2010 through May 2012 were extracted from the hospital pharmacy computer system. To assess the relationship between the usage of those antibiotics and the incidence of VRE (VRE-rate per 10 000 patients) a Poisson regression was performed.FindingsIn the study period 266 patients were colonized or infected with VRE. Specialty-specific VRE isolation was as follows: general surgical units (44 patients), bone marrow transplant unit (35 patients), general medical units (33 patients), cardiothoracic surgery (27 patients), nephrology (26 patients), haematooncology (22 patients), gastroenterology (17 patients), urology (17 patients), and the infectious diseases unit (11 patients). Hospital-wide consumption of glycopeptides was higher for teicoplanin than for vancomycin (26 242 versus 8677 DDDs). Specialty-specific VRE incidence significantly increased with the use of glycopeptides, fluoroquinolones or third generation cephalosporins (p < 0.001). The results of the Poisson regression for vancomycin (p = 0.0018) and teicoplanin (p < 0.0001) separately were both highly significant. Spearman’s correlation coefficient indicated a strong correlation between the two variables (rho = 0.8).ConclusionOverall usage of glycopeptides, fluoroquinolones or third generation cephalosporins contributed to the emergence of VRE in the hospital setting.

Outcome after Elective Percutaneous Coronary Intervention Depends on Age in Patients with Stable Coronary Artery Disease - An Analysis of Relative Survival in a Multicenter Cohort and an OCT Substudy.

Background Age is a strong predictor of survival in patients with coronary artery disease. In elder patients with increasing co-morbidities percutaneous coronary intervention (PCI) is associated with more complications and worse outcome. The calculation of relative survival rates adjusts for the “background” mortality in the general population by correcting for age and gender. We analyzed if elder patients after elective PCI have a worse relative survival compared to younger patient groups. Methods A total of 8,342 patients who underwent elective PCI at two high volume centers between 1998 and 2009 were analyzed. Results The survival of our patients after PCI (observed survival) was slightly lower compared to the general population (expected survival) resulting in a slightly decreasing relative survival curve. In a multivariate Cox regression model age amongst others was a strong predictor of survival. Stratifying patients according to their age the relative survival curves of younger patients (Quartile 1: <58 years; 2,046 patients), elder patients (Quartile 3: 66–73 years; 2,090 patients) and very old patients (Quartile 4: >73 years; 2,307 patients) were similar. The relative survival of mid-aged patients (Quartile 2: 58–65 years; 1,899 patients) was better than that of all other patient groups. The profile of cardiovascular risk factors differs between the various groups resulting in different composition and burden of coronary plaques in an optical coherence tomography sub-study. Conclusion Patients after elective PCI have a slightly worse long-term survival compared to the age- and sex-matched general population. This is also true for different groups of age except for mid-aged patients between 58 and 63 years. Elder patients between 66 and 73 years and above 73 years have a similar relative survival compared to younger patients below 58 years, and might therefore have similar benefit from elective PCI.

Center-based patient care enhances survival of elderly patients suffering from peripheral arterial disease.

Abstract Objectives: Recent advances in catheter-based intervention in patients with symptomatic peripheral arterial disease (PAD) have halved mortality. Mortality of PAD patients still remains high compared to other clinical forms of atherosclerosis. Intensified patient care might increase adherence to medical management and benefit the survival of PAD patients. Methods: Two patient cohorts were compared in a longitudinal prospective follow-up study. 370 PAD patients were included in the intensified center-based vascular medicine group (VMC group) and 332 PAD patients were treated by their usual primary care physician (PCP group). Survival in both groups was compared by Kaplan–Meier and Cox-regression analyses after 5 years. Results: Survival of patients in the VMC group was 90.8% compared to 66% in the PCP group. Thus, survival was improved by 24.9% by center-based care (absolute risk CI: 19–30.7%; 38% relative risk). PCP treatment increased all-cause mortality by a hazard ratio of 3.7 (95% CI: 2.5–5.5; p < .001). Mortality in the VMC group was significantly associated with the non-modifiable risk factors age, C-reactive protein, and nephropathy in multivariable analyses. Conclusion: These data imply that multi-morbid elderly PAD patients still benefit by intensified specialist care compared to the usual primary care setting. KEY MESSAGES Center-based patient care improves survival in patients with peripheral arterial disease; mortality was reduced from 82 to 21 events per 1000 patient-years (rate ratio 0.26). Mortality was related to age (HR 1.46), CRP (HR 1.36), and nephropathy (HR 2.7). A multifactorial approach combining adequate drug prescription, accomplishment of agreed goals and repetitive training to initiate, implement, and persist treatment adaptations was applied.

Angiopoietin-2 and Survival in Peripheral Artery Disease Patients

Survival of peripheral arterial disease (PAD) patients increased over the last decade due to increased use of secondary preventive medication and rapid revascularization of PAD patients. Angiogenetic markers such as vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and its receptor Tie-2 might be useful markers to assess the residual risk for mortality in PAD patients. The aim of this study was to evaluate angiogenetic markers for the prediction of mortality in a PAD cohort. For this purpose, 366 patients (mean age: 69 ± 10 years) with PAD Fontaine stage I or II were included and followed up over a 5-year study period. Serum Ang-2, Tie-2 and VEGF levels were measured by bead-based multiplex assay. All-cause mortality and major cardiovascular events (MACE) including all-cause death, non-fatal stroke and non-fatal myocardial infarction were analysed by Kaplan-Meier and Cox regression analyses after 5 years. Ang-2 was associated with Tie-2 (R = 0.151, p = 0.006) and VEGF levels (R = 0.160, p = 0.002). However, only Ang-2 was linked to all all-cause mortality in PAD patients (hazard ratio [HR]: 1.55 [1.23-2.15], p = 0.008) even after adjustment for age and gender, haemoglobin A1c, low-density lipoprotein cholesterol, systolic blood pressure and glomerular filtration rate (HR: 1.44 [1.03-2.00], p = 0.032). Furthermore, an association of Ang-2 and MACE in PAD patients (HR: 1.36 (1.03-1.78), p = 0.028) was found. This result implies that Ang-2 might be used as an additional marker to stratify PAD patients to predict poor mid-term life expectancy.

Automated tube voltage selection in pediatric non-contrast chest CT

Background Modern CT scanners provide automatic dose adjustment systems, which are promising options for reducing radiation dose in pediatric CT scans. Their impact on patient dose, however, has not been investigated sufficiently thus far. Objective To evaluate automated tube voltage selection (ATVS) in combination with automated tube current modulation (ATCM) in non-contrast pediatric chest CT, with regard to the diagnostic image quality. Materials and methods There were 160 non-contrast pediatric chest CT scans (8.7±5.4 years) analyzed retrospectively without and with ATVS. Correlations of volume CT Dose Index (CTDIvol) and effective diameter, with and without ATVS, were compared using Fisher’s z-transformation. Image quality was assessed by mean signal-difference-to-noise ratios (SDNR) in the aorta and in the left main bronchus using the independent samples t-test. Two pediatric radiologists and a general radiologist rated overall subjective Image quality. Readers’ agreement was assessed using weighted kappa coefficients. A p value <0.05 was considered significant. Results CTDIvol correlation with the effective diameter was r = 0.62 without and r = 0.80 with ATVS (CI: -0.04 to -0.60; p = 0.025). Mean SDNR was 10.88 without and 10.03 with ATVS (p = 0.0089). Readers’ agreement improved with ATVS (weighted kappa between pediatric radiologists from 0.1 (0.03–0.16) to 0.27 (0.09–0.45) with ATVS; between general and each pediatric radiologist from 0.1 (0.06–0.14) to 0.12 (0.05–0.20), and from 0.22 (0.11–0.34) to 0.36 (0.24–0.49)). Conclusion ATVS, combined with ATCM, results in a radiation dose reduction for pediatric non-contrast chest CT without a loss of diagnostic image quality and prevents errors in manual tube voltage setting, and thus protecting larger children against an unnecessarily high radiation exposure.

FABP4 and Cardiovascular Events in Peripheral Arterial Disease

Fatty acid–binding protein 4 (FABP4) is a possible biomarker of atherosclerosis. We evaluated FABP4 levels, for the first time, in patients with peripheral artery disease (PAD) and the possible association between baseline FABP4 levels and cardiovascular events over time. Patients (n = 327; mean age 69 ± 10 years) with stable PAD were enrolled in this study. Serum FABP4 was measured by bead-based multiplex assay. Cardiovascular events were analyzed by FABP4 tertiles using Kaplan-Meier and Cox regression analyses after 5 years. Serum FABP4 levels showed a significant association with the classical 3-point major adverse cardiovascular event (MACE) end point (including death, nonlethal myocardial infarction, or nonfatal stroke) in patients with PAD (P = .038). A standard deviation increase of FABP4 resulted in a hazard ratio (HR) of 1.33 (95% confidence interval [95% CI]: 1.03-1.71) for MACE. This association increased (HR: 1.47, 95% CI: 1.03-1.71) after multivariable adjustment (P = .020). Additionally, in multivariable linear regression analysis, FABP4 was linked to estimated glomerular filtration rate (P < .001), gender (P = .005), fasting triglycerides (P = .048), and body mass index (P < .001). Circulating FABP4 may be a useful additional biomarker to evaluate patients with stable PAD at risk of major cardiovascular complications.