Background Although clinical peer review is a well-established instrument for improving quality of care, clinical effectiveness is unclear. Methods In a pragmatic cluster randomised controlled trial, we randomly assigned 60 German Initiative Qualitätsmedizin member hospitals with the highest mortality rates in ventilated patients in 2016 to intervention and control groups. The primary outcome was hospital mortality rate in patients ventilated fore more than 24 hours. Clinical peer review was conducted in intervention group hospitals only. We assessed the impact of clinical peer review on mortality using a difference-in-difference approach by applying weighted least squares (WLS) regression to changes in age-adjusted and sex-adjusted standardised mortality ratios (SMRs) 1 year before and 1 year after treatment. Recommendations for improvement from clinical peer review and hospital survey data were used for impact and process analysis. Results We analysed 12 058 and 13 016 patients ventilated fore more than 24 hours in the intervention and control hospitals within the 1-year observation period. In-hospital mortality rates and SMRs were 40.6% and 1.23 in intervention group and 41.9% and 1.28 in control group hospitals in the preintervention period, respectively. The groups showed similar hospital (bed size, ownership) and patient (age, sex, mortality, main indications) characteristics. WLS regression did not yield a significant difference between intervention and control groups regarding changes in SMRs (estimate=0.04, 95% CI= −0.05 to 0.13, p=0.38). Mortality remained high in both groups (intervention: 41.8%, control: 42.1%). Impact and process analysis indicated few perceived outcome improvements or implemented process improvements following the introduction of clinical peer review. Conclusions This study did not provide evidence for reductions in mortality in patients ventilated for more than 24 hours due to clinical peer review. A stronger focus on identification of structures and care processes related to mortality is required to improve the effectiveness of clinical peer review.

Background: Intimate partner violence (IPV) is not only considered a serious public health issue and a cause of human suffering (National Center for Injury Prevention of the Centers for Disease Control and Prevention, 2015), IPV can be a barrier to utilization of care in vital life phases (Bonomi et al, 2009; Snow Jones, Dienemann, & Schollenberger, 2006), and a determinant of many serious negative health outcomes for affected individuals and their families (Silverman et al, 2020). As a significant contributor to health, social, and economic disparities, violence jeopardizes the fabric of families and transcends all levels of socioeconomic status (Rhodes, 2012). Among those who suffer serious to fatal consequences as a direct result of IPV, the perinatal period has only recently received special attention in research and is extremely scarce (WHO, 2011). This is particularly the case as the exposure/context of IPV may be further complicated by societal crises such as natural disasters and pandemics, where the threat of violence and its health consequences may be heightened (Yehuda et al, 2008). Objectives: The objectives of this dissertation were to address the knowledge gaps pertaining to perinatal IPV and violence experiences during the COVID-19 pandemic. It had three specialist articles, two of which were reviews of the literature, and one was a population-based empirical study. The objectives of the dissertation were as follows: 1) To explore uni- and bi-directional IPV prevalence estimates and associated factors during the perinatal period (Paper I) (Mojahed et al, 2021a); 2) To investigate a broader range of pre- pandemic contexts of social and geographical isolation and their associations with IPV, as well as to provide reliable, preliminary knowledge of their potential impact during the COVID- 19 pandemic (Paper II) (Mojahed et al, 2021b; 3) To explore the 12-month prevalence of psychological, physical, and sexual IPV within an existing cohort, which consists of women and men, as well as to detect any possible changes during the COVID-19 pandemic in the experienced IPV behaviors as opposed to pre-pandemic times (Paper III) (Mojahed et al, 2023); 4) To explore factors that could prospectively predict IPV victimization (Paper III). Materials and Methods: Paper I involved a qualitative synthesis of the literature. Due to the heterogeneity of prevalence studies and varying violence definitions, quantitative analyses were not feasible for this review. The paper investigated prevalence estimates of perinatal IPV among intimate partners and explored associated factors. Information such as author, year of publication, recruitment setting, study design, sample size, directionality of IPV, prevalence estimates, and types of violence were extracted and tabulated. The integrative ecological model was used to consider population characteristics and (gender-based) associated factors relevant to IPV prevalence. Paper II was a rapid review conducted following Cochrane guidelines to address the urgency of studying IPV in the context of the COVID-19 pandemic. The review focused on the correlation between social and geographical isolation and IPV. Paper III utilized data from the population-based longitudinal study DREAMCORONA. Descriptive analyses were performed to determine the prevalence of IPV victimization among women and men, examining changes during the pandemic. Pearson correlation analyses and multiple logistic regression analysis were conducted to identify associations and potential predictors of IPV. The results were presented as odds ratios with confidence intervals. Results: In Paper I, several key findings were reported. Psychological uni-directional IPV against female partners was most prevalent during pregnancy. Studies comparing IPV prevalence before and after childbirth showed mixed results, with some reporting a decrease and others reporting an increase in IPV after birth. Risk factors at the individual, family, community, and societal levels were identified, including socioeconomic status, substance use, insufficient prenatal care utilization, low self-esteem, unplanned pregnancy, lack of support, and certain social and ethnic identities. Paper II found that lack of social support increased the risk of IPV victimization, and the compounding effect of social and geographical isolation heightened this risk. It also revealed that social isolation correlated with physical and sexual IPV among female drug users and predicted various forms of IPV among immigrant women. In Paper III, it was found that around 50% of women and 40% of men experienced some form of IPV in the last 12 months. Psychological aggression was the most prevalent form of violence reported. The majority of women and men reported no change in victimization by psychological and physical violence during the pandemic. On the other hand, about a quarter of (expectant) mothers (27%) and fathers (22-24%) reported an increase in psychological and physical IPV. With regard to sexual violence, neither mothers nor fathers reported any changes during the pandemic. Higher partnership satisfaction reduced the likelihood of IPV victimization, while symptoms of anger-hostility increased this probability. Conclusions: Considering the burden of perinatal IPV and the impact of the COVID-19 pandemic on IPV, this dissertation highlights the urgent need for effective preventive interventions. The findings suggest the importance of initiating antenatal care and delivering in clinical settings, as these factors were associated with a lower risk of perinatal IPV. Routine screening for IPV in obstetric care is crucial, and healthcare providers should be aware of the elevated risk for mental health distress among perinatal partners exposed to IPV. As experiences of IPV remained largely unchanged during the pandemic, there is a strong recommendation to strengthen and improve access to support services. Alternative support measures such as messenger services and telemedicine should be accessible and reliable for victims of severe IPV who may face increased isolation. Raising awareness about IPV is essential for individuals in informal and formal sectors, as well as family and friends within the immediate social network of those at risk. The findings also support the use of programs targeting adverse interaction patterns, particularly psychological aggression. Future research should focus on associated factors of IPV during the peripartum period and other critical life phases or societal events. It is crucial to adopt ecological and intersectional perspectives to gain a comprehensive understanding of IPV. Furthermore, including the perspective of the other partner in IPV research can provide valuable context for better prevention and intervention strategies.

Elektrische und magnetische Emitter können zur Erforschung unterschiedlicher plasmonischer Nanostrukturen genutzt werden. Indem wir die Änderung der Abstrahldynamik und in der Lebensdauer bestimmen, detektieren wir die photonische lokale Zustandsdichte. Diese Zustandsdichte, die eine Eigenschaft der Umgebung ist, ermöglicht uns nicht nur Rückschlüsse auf die elektronischen und andere physikalische Eigenschaften dieser zu treffen sondern auch die allgemeinen Eigenschaften der plasmonischen Nanostruktur im Bezug auf Licht-Materie Kopplung zu bestimmen. Eine starke Licht-Materie-Kopplung ist für die zukünftige Anwendung im Bereich der Quantentechnologien wichtig. Wenn Emitter hierbei mit plasmonischen Nanostrukturen koppeln, fokussieren letztere nicht nur das emittierte Lichts an der Oberfläche im Subwellenlängenbereich sondern ermöglichen durch die Feldüberhöhung an der Oberfläche auch eine starke Licht-Materie-Kopplung. In der Arbeit konzentrieren wir uns auf zwei grundlegend unterschiedliche plasmonische Systeme: zunächst untersuchen wir analytisch den Einfluss von Graphen auf elektrische und magnetische Emitter und diskutieren dann die Lebensdaueränderungen und Strahlungsdynamiken in der Nähe von Silber- und Goldnanostrukturen. Im ersten Teil der Arbeit analysieren wir den Einfluss von Graphen mit einer Bandlücke auf den Emitter und zeigen Möglichkeiten zur experimentellen Bestimmung der Bandlücke auf. Im zweiten Teil modellieren wir die Propagation elektromagnetischer Felder im dreidimensionalen Raum mit Hilfe der Diskontinuierlichen Galerkin Zeitraum Methode mit erweiterten Funktionalitäten. Diese verwenden wir sowohl zur theoretischen Modellierung des ersten dreidimensionalen Fluoreszenlebensdauerabbildungsmikroskopie mit einem einzelnen Quantenemitter als auch zur selbstkonsistent Beschreibung von Emittern in der Nähe eines Goldpentamers. Die Kombination der Studien betont die Stärke von Emittern elektrische, optische und magnetische Eigenschaften zu detektieren. / Electric and magnetic emitters can be used to probe different plasmonic nanostructures. By determining the modification of the radiation dynamics and the lifetimes, we can measure the photonic local density of states. This, being a property of the enviroment, does not only allow us to draw conclusions regarding the electronic and other physical properties of the latter but also regarding the general light-matter coupling properties of the plasmonic nanostructure. A strong light-matter coupling is important for future applications in quantum technology. If emitters couple specifically to plasmonic nanostructure, the latter do not only focus the emitted light at the sub-wavelength scale at the surface of the structure but also allow for such a strong light-matter coupling due to the field enhancement at the surface. In this work, we focus on two different basic plasmonic systems: first, we study analytically the influence of graphene on electric and magnetic emitters, and second we discuss lifetime modifications and radiation dynamics close to silver and gold nanostructures. In the first part of this work, we specifically focus on the influence of graphene exhibiting a finite band gap on the emitter. In the second part, we model the propagation of electromagnetic fields in three-dimensional space making use of the discontinuous Galerkin time-domain method with extended functionalities. This framework we apply to model the first three-dimensional scanning-probe fluorescence-lifetime imaging microscopy by use of a single quantum-emitter as well as for a self-consistent description of emitters in the proximity of a gold pentamer. The combination of these studies stress that the strength of emitters lies in the detection of electronic, optical and magnetic properties.

In dieser Arbeit werden die nichtlokalen sowie nichtlinearen Eigenschaften plasmonischer Nanopartikel behandelt, wie sie im hydrodynamischen Modell enthalten sind. Das hydrodynamische Materialmodell stellt eine Erweiterung des Drude Modells dar, in der Korrekturen in der Beschreibung des Elektronenplasmas berücksichtigt werden. Einer ausführlichen Einführung des Materialmodells folgt eine analytische Diskussion der Auswirkungen der Nichtlokalität am Beispiel eines einzelnen Zylinders. Hierbei werden die durch die Nichtlokalität herbeigeführten Frequenzverschiebungen in den Streu- und Absorptionsspektren quantifiziert und asymptotisch behandelt. Des Weiteren wird mit Hilfe einer konformen Abbildung das Problem eines zylindrischen Dimers in der Elektrostatischen Näherung gelöst und die Moden der Struktur bestimmt. Diese Untersuchungen dienen als maßgebliche Grundlage für weiterführende numerische Studien die mit der diskontinuierlichen Galerkin Zeitraummethode durchgeführt werden. Die durch die analytischen Betrachtungen gewonnene Kenntnis der Moden ermöglicht es, im Zusammenhang mit gruppentheoretischen Betrachtungen und numerischen Untersuchungen, rigorose Auswahlregeln für die Anregung der Moden durch lineare und nichtlineare Prozesse aufzustellen. In weiterführenden numerischen Simulationen werden außerdem Strukturen niedrigerer Symmetrie, auf die sich die Auswahlregeln übertragen lassen, untersucht. Zudem werden numerische Studien präsentiert in denen der Einfluss der Nichtlokalität auf Feldüberhöhungen in Dimeren und doppel-resonantes Verhalten (es liegt sowohl bei der Frequenz des eingestrahlten Lichtes als auch bei der zweiten harmonischen eine Resonanz vor) untersucht werden. / This thesis deals with the nonlocal and nonlinear properties of plasmonic nanoparticles, as described by the hydrodynamic model. The hydrodynamic material model represents an extension of the Drude model that contains corrections to the descriptions of the electron plasma. After a thorough derivation of the material model, analytical discussions of nonlocality are presented for the example of a single cylinder. The frequency shifts in the scattering and absorption spectra are quantified and treated asymptotically. Furthermore, by applying a conformal map, the problem of a cylindrical dimer is solved in the electrostatic limit and the modes of the structure are determined. These investigations lay the foundations for numerical investigations which are performed employing the discontinuous Galerkin time domain method. The analytical knowledge of the modes, in conjunction with group theoretical considerations and numerical analysis, enables the formulation of rigorous selection rules for the excitation of modes by linear and nonlinear processes. In further numerical studies, the influence of nonlocality on the field enhancement in dimer structures and double-resonant behavior (a resonance is found at the frequency of the incoming light and at the second harmonic) are investigated.