@article{EliasHeuschmannSchmittetal.2013, author = {Elias, Johannes and Heuschmann, Peter U. and Schmitt, Corinna and Eckhardt, Frithjof and Boehm, Hartmut and Maier, Sebastian and Kolb-M{\"a}urer, Annette and Riedmiller, Hubertus and M{\"u}llges, Wolfgang and Weisser, Christoph and Wunder, Christian and Frosch, Matthias and Vogel, Ulrich}, title = {Prevalence dependent calibration of a predictive model for nasal carriage of methicillin-resistant Staphylococcus aureus}, series = {BMC Infectious Diseases}, journal = {BMC Infectious Diseases}, doi = {10.1186/1471-2334-13-111}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96091}, year = {2013}, abstract = {Background Published models predicting nasal colonization with Methicillin-resistant Staphylococcus aureus among hospital admissions predominantly focus on separation of carriers from non-carriers and are frequently evaluated using measures of discrimination. In contrast, accurate estimation of carriage probability, which may inform decisions regarding treatment and infection control, is rarely assessed. Furthermore, no published models adjust for MRSA prevalence. Methods Using logistic regression, a scoring system (values from 0 to 200) predicting nasal carriage of MRSA was created using a derivation cohort of 3091 individuals admitted to a European tertiary referral center between July 2007 and March 2008. The expected positive predictive value of a rapid diagnostic test (GeneOhm, Becton \& Dickinson Co.) was modeled using non-linear regression according to score. Models were validated on a second cohort from the same hospital consisting of 2043 patients admitted between August 2008 and January 2012. Our suggested correction score for prevalence was proportional to the log-transformed odds ratio between cohorts. Calibration before and after correction, i.e. accurate classification into arbitrary strata, was assessed with the Hosmer-Lemeshow-Test. Results Treating culture as reference, the rapid diagnostic test had positive predictive values of 64.8\% and 54.0\% in derivation and internal validation corhorts with prevalences of 2.3\% and 1.7\%, respectively. In addition to low prevalence, low positive predictive values were due to high proportion (> 66\%) of mecA-negative Staphylococcus aureus among false positive results. Age, nursing home residence, admission through the medical emergency department, and ICD-10-GM admission diagnoses starting with "A" or "J" were associated with MRSA carriage and were thus included in the scoring system, which showed good calibration in predicting probability of carriage and the rapid diagnostic test's expected positive predictive value. Calibration for both probability of carriage and expected positive predictive value in the internal validation cohort was improved by applying the correction score. Conclusions Given a set of patient parameters, the presented models accurately predict a) probability of nasal carriage of MRSA and b) a rapid diagnostic test's expected positive predictive value. While the former can inform decisions regarding empiric antibiotic treatment and infection control, the latter can influence choice of screening method.}, language = {en} } @article{WurmbVollmerSefrinetal.2015, author = {Wurmb, Thomas and Vollmer, Tina and Sefrin, Peter and Kraus, Martin and Happel, Oliver and Wunder, Christian and Steinisch, Andrias and Roewer, Norbert and Maier, Sebastian}, title = {Monitoring of in-hospital cardiac arrest events with the focus on Automated External Defibrillators - a retrospective observational study}, series = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, volume = {23}, journal = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, number = {87}, doi = {10.1186/s13049-015-0170-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125756}, year = {2015}, abstract = {Background Patients with cardiac arrest have lower survival rates, when resuscitation performance is low. In In-hospital settings the first responders on scene are usually nursing staff without rhythm analysing skills. In such cases Automated External Defibrillators (AED) might help guiding resuscitation performance. At the Wuerzburg University Hospital (Germany) an AED-program was initiated in 2007. Aim of the presented study was to monitor the impact of Automated External Defibrillators on the management of in-hospital cardiac arrest events. Methods The data acquisition was part of a continuous quality improvement process of the Wuerzburg University Hospital. For analysing the CPR performance, the chest compression rate (CCR), compression depth (CCD), the no flow fraction (NFF), time interval from AED-activation to the first compression (TtC), the time interval from AED-activation to the first shock (TtS) and the post schock pause (TtCS) were determined by AED captured data. A questionnaire was completed by the first responders. Results From 2010 to 2012 there were 359 emergency calls. From these 53 were cardiac arrests with an AED-application. Complete data were available in 46 cases. The TtC was 34 (32-52) seconds (median and IQR).The TtS was 30 (28-32) seconds (median and IQR) . The TtCS was 4 (3-6) seconds (median and IQR) . The CCD was 5.5 ± 1 cm while the CCR was 107 ± 11/min. The NFF was calculated as 41 \%. ROSC was achieved in 21 patients (45 \%), 8 patients (17 \%) died on scene and 17 patients (37 \%) were transferred under ongoing CPR to an Intensive Care Unit (ICU). Conclusion The TtS and TtC indicate that there is an AED-user dependent time loss. These time intervals can be markedly reduced, when the user is trained to interrupt the AED's "chain of advices" by placing the electrode-paddles immediately on the patient's thorax. At this time the AED switches directly to the analysing mode. Intensive training and adaption of the training contents is needed to optimize the handling of the AED in order to maximize its advantages and to minimize its disadvantages.}, language = {en} }