Unkel, Steffen

[["dc.bibliographiccitation.firstpage","351"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Metrika"],["dc.bibliographiccitation.lastpage","362"],["dc.bibliographiccitation.volume","80"],["dc.contributor.author","Unkel, Steffen"],["dc.date.accessioned","2018-11-07T10:25:48Z"],["dc.date.available","2018-11-07T10:25:48Z"],["dc.date.issued","2017"],["dc.description.abstract","In shared frailty models for bivariate survival data the frailty is identifiable through the cross-ratio function (CRF), which provides a convenient measure of association for correlated survival variables. The CRF may be used to compare patterns of dependence across models and data sets. We explore the shape of the CRF for the families of one-sided truncated normal and folded normal frailty distributions."],["dc.identifier.doi","10.1007/s00184-016-0608-6"],["dc.identifier.isi","000397497100007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42927"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Springer"],["dc.publisher.place","Heidelberg"],["dc.relation.issn","1435-926X"],["dc.relation.issn","0026-1335"],["dc.title","On the shape of the cross-ratio function in bivariate survival models induced by truncated and folded normal frailty distributions"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","321"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Hospital Infection"],["dc.bibliographiccitation.lastpage","327"],["dc.bibliographiccitation.volume","103"],["dc.contributor.author","Fehling, P."],["dc.contributor.author","Hasenkamp, J."],["dc.contributor.author","Unkel, S."],["dc.contributor.author","Thalmann, I."],["dc.contributor.author","Hornig, S."],["dc.contributor.author","Trümper, L."],["dc.contributor.author","Scheithauer, S."],["dc.date.accessioned","2020-12-10T14:25:09Z"],["dc.date.available","2020-12-10T14:25:09Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1016/j.jhin.2019.06.004"],["dc.identifier.issn","0195-6701"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/72459"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Effect of gloved hand disinfection on hand hygiene before infection-prone procedures on a stem cell ward"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Journal of Statistical Planning and Inference"],["dc.bibliographiccitation.lastpage","11"],["dc.bibliographiccitation.volume","182"],["dc.contributor.author","Unkel, Steffen"],["dc.date.accessioned","2018-11-07T10:27:10Z"],["dc.date.available","2018-11-07T10:27:10Z"],["dc.date.issued","2017"],["dc.description.abstract","Shared frailty models are frequently used for inducing dependence between survival times. In this paper, we consider bivariate current status data that are reasonable to model by shared frailty models. A time-dependent association measure that has a conditional probability interpretation is revisited for its potential application to such data. We propose a method of estimation and derive asymptotic standard errors for this measure. Its small sample performance and its performance in assessing the temporal variation in the strength of association in realistic scenarios is investigated by means of experiments. We show that the measure based on the conditional probability can vary with time even in the absence of any time-dependent effects. Furthermore, we give evidence that it lacks interpretability in suggesting appropriate frailty models. We provide an illustration with multivariate current status data arising from a community-based study of cardiovascular diseases in Taiwan. We compare the observed patterns of association with the ones obtained by employing a fairly new time-varying association measure that is relevant for shared frailty models, owing to its connection to the cross-ratio function, and which serves as a diagnostic tool for suggesting classes of frailty distributions with constant, increasing or decreasing association over time. (C) 2016 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.jspi.2016.09.009"],["dc.identifier.isi","000389173900001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43193"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1873-1171"],["dc.relation.issn","0378-3758"],["dc.title","On the conditional probability for assessing time dependence of association in shared frailty models with bivariate current status data"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","859"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Drugs & Aging"],["dc.bibliographiccitation.lastpage","869"],["dc.bibliographiccitation.volume","35"],["dc.contributor.author","Djukic, Marija"],["dc.contributor.author","Braun, Larissa Maria"],["dc.contributor.author","Unkel, Steffen"],["dc.contributor.author","Jacobshagen, Claudius"],["dc.contributor.author","Nau, Roland"],["dc.date.accessioned","2020-12-10T14:14:45Z"],["dc.date.available","2020-12-10T14:14:45Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1007/s40266-018-0571-1"],["dc.identifier.eissn","1179-1969"],["dc.identifier.issn","1170-229X"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/71474"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Introduction of Non-Vitamin K Antagonist Anticoagulants Strongly Increased the Rate of Anticoagulation in Hospitalized Geriatric Patients with Atrial Fibrillation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","68"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of the American Academy of Audiology"],["dc.bibliographiccitation.lastpage","79"],["dc.bibliographiccitation.volume","26"],["dc.contributor.author","Kiessling, Juergen"],["dc.contributor.author","Leifholz, Melanie"],["dc.contributor.author","Unkel, Steffen"],["dc.contributor.author","Pons-Kuehnemann, Joern"],["dc.contributor.author","Jespersen, Charlotte Thunberg"],["dc.contributor.author","Pedersen, Jenny Nesgaard"],["dc.date.accessioned","2018-11-07T10:03:57Z"],["dc.date.available","2018-11-07T10:03:57Z"],["dc.date.issued","2015"],["dc.description.abstract","Background: In-situ audiometry is a hearing aid feature that enables the measurement of hearing threshold levels through the hearing instrument using the built-in sound generator and the hearing aid receiver. This feature can be used in hearing aid fittings instead of conventional pure-tone audiometry (PTA), particularly in places where no standard audiometric equipment is available. Differences between conventional and in-situ thresholds are described and discussed for some particular hearing aids. No previous investigation has measured and compared these differences for a number of current hearing aid models by various manufacturers across a wide range of hearing losses. Purpose: The purpose of this study was to perform a model-based comparison of conventionally and insitu measured hearing thresholds. Data were collected for a range of hearing aid devices to study and generalize the effects that may occur under clinical conditions. Research Design: Research design was an experimental and regression study. Study Sample: A total of 30 adults with sensorineural hearing loss served as test persons. They were assigned to three subgroups of 10 subjects with mild (M), moderate to severe (MS), and severe (S) sensorineural hearing loss. Intervention: All 30 test persons underwent both conventional PTA and in-situ audiometry with four hearing aid models by various manufacturers. Data Collection and Analysis: The differences between conventionally and in-situ measured hearing threshold levels were calculated and evaluated by an exploratory data analysis followed by a sophisticated statistical modeling process. Results: At 500 and 1500 Hz, almost all threshold differences (conventional PTA minus in-situ data) were negative, i.e., in the low to mid frequencies, hearing loss was overestimated by most devices relative to PTA. At 4000 Hz, the majority of differences (7 of 12) were positive, i.e., in the frequency range above 1500 Hz, hearing loss was frequently underestimated. As hearing loss increased (M -> MS -> S), the effect of the underestimation decreased. At 500 and 1500 Hz, Resound devices showed the smallest threshold deviations, followed by Phonak, Starkey, and Oticon instruments. At 4000 Hz, this observed pattern partly disappeared and Starkey and Oticon devices showed a reversed effect with increasing hearing loss (M -> MS -> S). Because of high standard errors for the estimates, only a few explicit rankings of the devices could be established based on significant threshold differences (5% level). Conclusions: Differences between conventional PTA and in-situ threshold levels may be attributed to (1) frequency, (2) device/hearing loss, and (3) calibration/manufacturer effects. Frequency effects primarily resulting in an overestimation of hearing loss by in-situ audiometry in the low and mid frequencies are mainly due to sound drain-off through vents and leaks. Device/hearing loss effects may be due to leakage as well as boundary effects because in-situ audiometry is confined to a limited measurement range. Finally, different calibration approaches may result in different offset levels between PTA and in-situ audiometry calibration. In some cases, the observed threshold differences of up to 10-15 dB may translate to varied hearing aid fittings for the same user depending on how hearing threshold levels were measured."],["dc.description.sponsorship","GN ReSound"],["dc.identifier.doi","10.3766/jaaa.26.1.8"],["dc.identifier.isi","000347763800008"],["dc.identifier.pmid","25597462"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38589"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Acad Audiology"],["dc.relation.issn","2157-3107"],["dc.relation.issn","1050-0545"],["dc.title","A Comparison of Conventional and In-Situ Audiometry on Participants with Varying Levels of Sensorineural Hearing Loss"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Strahlentherapie und Onkologie"],["dc.bibliographiccitation.volume","191"],["dc.contributor.author","Schoetz, U."],["dc.contributor.author","Shnayien, S."],["dc.contributor.author","Kinzel, L."],["dc.contributor.author","Hess, J."],["dc.contributor.author","Zitzelsberger, H."],["dc.contributor.author","Klein, D."],["dc.contributor.author","Jendrossek, V."],["dc.contributor.author","Belka, C."],["dc.contributor.author","Unkel, Steffen"],["dc.contributor.author","Lauber, Kirsten"],["dc.date.accessioned","2018-11-07T09:56:06Z"],["dc.date.available","2018-11-07T09:56:06Z"],["dc.date.issued","2015"],["dc.format.extent","S121"],["dc.identifier.isi","000362544800269"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36897"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Urban & Vogel"],["dc.publisher.place","Munich"],["dc.relation.conference","21st Annual Meeting of the German-Society-for-Radiation-Oncology"],["dc.relation.eventlocation","Hamburg, GERMANY"],["dc.relation.issn","1439-099X"],["dc.relation.issn","0179-7158"],["dc.title","Inherent radioresistance of head and neck squamous cell carcinoma cells: principal component analysis identifies cellular senescence as a crucial driver"],["dc.type","conference_abstract"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2123"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Age and Ageing"],["dc.bibliographiccitation.lastpage","2132"],["dc.bibliographiccitation.volume","50"],["dc.contributor.author","Dohrendorf, Carla Maria"],["dc.contributor.author","Unkel, Steffen"],["dc.contributor.author","Scheithauer, Simone"],["dc.contributor.author","Kaase, Martin"],["dc.contributor.author","Meier, Volker"],["dc.contributor.author","Fenz, Diana"],["dc.contributor.author","Sasse, Jürgen"],["dc.contributor.author","Wappler, Manfred"],["dc.contributor.author","Schweer-Herzig, Jutta"],["dc.contributor.author","Friede, Tim"],["dc.contributor.author","Seele, Jana"],["dc.date.accessioned","2022-02-01T10:31:20Z"],["dc.date.available","2022-02-01T10:31:20Z"],["dc.date.issued","2021"],["dc.description.abstract","Abstract Objectives To reduce infections with Clostridioides difficile (CDI) in geriatric patients by interventions easily implementable in standard clinical care. Methods Prevalence and incidence of CDI between January 2015 and February 2020 were analysed (n = 25,311 patients). Pre-intervention status was assessed from April 2016 to March 2017 (n = 4,922). Between May 2017 and August 2019, a monocentric interventional crossover study (n = 4,655) was conducted including standard care and three interventions: (A) sporicidal cleaning of hospital wards, (B) probiotics and (C) improvement in personal hygiene for CDI patients. This was followed by a multicentric comparison of the interventional bundle (A + B + C) between September 2019 and February 2020 (n = 2,593) with the pre-intervention phase. In 98 CDI cases and matched controls individual risk factors for the development of CDI were compared. Results Time series analyses of CDI cases revealed a reduction in the prevalence of CDI in all three participating centres prior to the multicentric intervention phase. In the monocentric phase, no effect of individual interventions on CDI prevalence was identified. However, an aggregated analysis of CDI cases comparing the pre-intervention and the multicentric phase revealed a significant reduction in CDI prevalence. Risk factors for the development of CDI included use of antibiotics, anticoagulants, previous stay in long-term care facilities, prior hospital admissions, cardiac and renal failure, malnutrition and anaemia. Conclusions The observed reduction in CDI may be attributed to heightened awareness of the study objectives and specific staff training. Individual interventions did not appear to reduce CDI prevalence. A further randomised trial would be necessary to confirm whether the bundle of interventions is truly effective."],["dc.description.abstract","Abstract Objectives To reduce infections with Clostridioides difficile (CDI) in geriatric patients by interventions easily implementable in standard clinical care. Methods Prevalence and incidence of CDI between January 2015 and February 2020 were analysed (n = 25,311 patients). Pre-intervention status was assessed from April 2016 to March 2017 (n = 4,922). Between May 2017 and August 2019, a monocentric interventional crossover study (n = 4,655) was conducted including standard care and three interventions: (A) sporicidal cleaning of hospital wards, (B) probiotics and (C) improvement in personal hygiene for CDI patients. This was followed by a multicentric comparison of the interventional bundle (A + B + C) between September 2019 and February 2020 (n = 2,593) with the pre-intervention phase. In 98 CDI cases and matched controls individual risk factors for the development of CDI were compared. Results Time series analyses of CDI cases revealed a reduction in the prevalence of CDI in all three participating centres prior to the multicentric intervention phase. In the monocentric phase, no effect of individual interventions on CDI prevalence was identified. However, an aggregated analysis of CDI cases comparing the pre-intervention and the multicentric phase revealed a significant reduction in CDI prevalence. Risk factors for the development of CDI included use of antibiotics, anticoagulants, previous stay in long-term care facilities, prior hospital admissions, cardiac and renal failure, malnutrition and anaemia. Conclusions The observed reduction in CDI may be attributed to heightened awareness of the study objectives and specific staff training. Individual interventions did not appear to reduce CDI prevalence. A further randomised trial would be necessary to confirm whether the bundle of interventions is truly effective."],["dc.identifier.doi","10.1093/ageing/afab169"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/98833"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-517"],["dc.relation.eissn","1468-2834"],["dc.relation.issn","0002-0729"],["dc.title","Reduced Clostridioides difficile infections in hospitalised older people through multiple quality improvement strategies"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Emerging Infectious Diseases"],["dc.bibliographiccitation.volume","26"],["dc.contributor.author","Hermann, Peter"],["dc.contributor.author","Treig, Johannes"],["dc.contributor.author","Unkel, Steffen"],["dc.contributor.author","Goebel, Stefan"],["dc.contributor.author","Bunck, Timothy"],["dc.contributor.author","Jünemann, Martha"],["dc.contributor.author","Friede, Tim"],["dc.contributor.author","Zerr, Inga"],["dc.date.accessioned","2021-04-14T08:23:52Z"],["dc.date.available","2021-04-14T08:23:52Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.3201/eid2608.191159"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/81081"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation.eissn","1080-6059"],["dc.relation.issn","1080-6040"],["dc.title","Sporadic Creutzfeldt-Jakob Disease among Physicians, Germany, 1993–2018"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]