TY - JOUR A1 - Weibel, Stephanie A1 - Popp, Maria A1 - Reis, Stefanie A1 - Skoetz, Nicole A1 - Garner, Paul A1 - Sydenham, Emma T1 - Identifying and managing problematic trials: A research integrity assessment tool for randomized controlled trials in evidence synthesis JF - Research Synthesis Methods N2 - Evidence synthesis findings depend on the assumption that the included studies follow good clinical practice and results are not fabricated or false. Studies which are problematic due to scientific misconduct, poor research practice, or honest error may distort evidence synthesis findings. Authors of evidence synthesis need transparent mechanisms to identify and manage problematic studies to avoid misleading findings. As evidence synthesis authors of the Cochrane COVID-19 review on ivermectin, we identified many problematic studies in terms of research integrity and regulatory compliance. Through iterative discussion, we developed a research integrity assessment (RIA) tool for randomized controlled trials for the update of this Cochrane review. In this paper, we explain the rationale and application of the RIA tool in this case study. RIA assesses six study criteria: study retraction, prospective trial registration, adequate ethics approval, author group, plausibility of methods (e.g., randomization), and plausibility of study results. RIA was used in the Cochrane review as part of the eligibility check during screening of potentially eligible studies. Problematic studies were excluded and studies with open questions were held in awaiting classification until clarified. RIA decisions were made independently by two authors and reported transparently. Using the RIA tool resulted in the exclusion of >40% of studies in the first update of the review. RIA is a complementary tool prior to assessing “Risk of Bias” aiming to establish the integrity and authenticity of studies. RIA provides a platform for urgent development of a standard approach to identifying and managing problematic studies. KW - COVID-19 pandemic KW - systematic review KW - research integrity KW - randomized controlled trial KW - good clinical practice KW - evidence synthesis Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318236 VL - 14 IS - 3 SP - 357 EP - 369 ER - TY - JOUR A1 - Schmid, Benedikt A1 - Griesel, Mirko A1 - Fischer, Anna-Lena A1 - Romero, Carolina S. A1 - Metzendorf, Maria-Inti A1 - Weibel, Stephanie A1 - Fichtner, Falk T1 - Awake prone positioning, high-flow nasal oxygen and non-invasive ventilation as non-invasive respiratory strategies in COVID-19 acute respiratory failure: a systematic review and meta-analysis JF - Journal of Clinical Medicine N2 - Background: Acute respiratory failure is the most important organ dysfunction of COVID-19 patients. While non-invasive ventilation (NIV) and high-flow nasal cannula (HFNC) oxygen are frequently used, efficacy and safety remain uncertain. Benefits and harms of awake prone positioning (APP) in COVID-19 patients are unknown. Methods: We searched for randomized controlled trials (RCTs) comparing HFNC vs. NIV and APP vs. standard care. We meta-analyzed data for mortality, intubation rate, and safety. Results: Five RCTs (2182 patients) were identified. While it remains uncertain whether HFNC compared to NIV alters mortality (RR: 0.92, 95% CI 0.65–1.33), HFNC may increase rate of intubation or death (composite endpoint; RR 1.22, 1.03–1.45). We do not know if HFNC alters risk for harm. APP compared to standard care probably decreases intubation rate (RR 0.83, 0.71–0.96) but may have little or no effect on mortality (RR: 1.08, 0.51–2.31). Conclusions: Certainty of evidence is moderate to very low. There is no compelling evidence for either HFNC or NIV, but both carry substantial risk for harm. The use of APP probably has benefits although mortality appears unaffected. KW - respiratory failure KW - non-invasive ventilation KW - high-flow nasal cannula KW - awake prone positioning KW - COVID-19 KW - systematic review Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-255225 SN - 2077-0383 VL - 11 IS - 2 ER - TY - JOUR A1 - Hackenbroich, Samantha A1 - Kranke, Peter A1 - Meybohm, Patrick A1 - Weibel, Stephanie T1 - Include or not to include conference abstracts in systematic reviews? Lessons learned from a large Cochrane network meta-analysis including 585 trials JF - Systematic Reviews N2 - Background Systematic reviews attempt to gather all available evidence. Controversy exists regarding effort and benefit of including study results presented at conferences only. We recently published a Cochrane network meta-analysis (NMA) including 585 randomized controlled trials comparing drugs for prevention of postoperative nausea and vomiting (PONV). Studies published as conference abstracts only were excluded. This study aimed to include all eligible studies published as abstracts only, assessing their added value regarding reporting quality and effect on the review’s interpretation. Methods Conference abstracts were searched in the review’s excluded studies and conference proceedings of anaesthesiologic societies. We assessed their reporting quality regarding review’s eligibility criteria, Cochrane ‘risk of bias’ assessment tool 1.0, and adherence to CONSORT (Consolidated Standards of Reporting Trials) for abstracts. Abstracts were included in sensitivity NMA, and impact on the NMA structure was investigated. Results We identified 90 abstracts. A total of 14% (13/90) were eligible. A total of 86% (77/90) are awaiting classification due to insufficient reporting of review’s eligibility criteria. In abstracts awaiting classification, sufficient information was missing on standardization of anaesthesia in 71% (55/77), age of participants in 56% (43/77), and outcome details in 46% (36/77). A total of 73% (66/90) of abstracts lacked sufficient information on 15/25 data extraction items. Reported study characteristics of abstracts were comparable to included studies of the review. A total of 62% (56/90) of abstract trials were assessed as overall high risk of bias due to poor reporting. Median adherence to CONSORT for abstracts was 24% (IQR, 18 to 29%). Six of the 13 eligible abstracts reported relevant outcome data in sufficient detail for NMA on seven outcomes of the Cochrane review. Inclusion of abstracts did not substantially change the network structure, network effect estimates, ranking of treatments, or the conclusion. Certainty of evidence for headache on palonosetron use was upgraded from very low to low. Conclusions Most conference abstracts on PONV were insufficiently reported regarding review’s narrow inclusion criteria and could not be included in NMA. The resource-intensive search and evaluation of abstracts did not substantially extent the full-text evidence base of the review, given the few adequately reported abstracts. Conferences should oblige authors to adhere to CONSORT for abstracts. KW - systemic reviews KW - conference abstracts KW - meta-analysis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-299660 VL - 11 IS - 1 ER - TY - JOUR A1 - Riemer, Manuel A1 - Kranke, Peter A1 - Helf, Antonia A1 - Mayer, Debora A1 - Popp, Maria A1 - Schlesinger, Tobias A1 - Meybohm, Patrick A1 - Weibel, Stephanie T1 - Trial registration and selective outcome reporting in 585 clinical trials investigating drugs for prevention of postoperative nausea and vomiting JF - BMC Anesthesiology N2 - Background: Selective outcome reporting in clinical trials introduces bias in the body of evidence distorting clinical decision making. Trial registration aims to prevent this bias and is suggested by the International Committee of Medical Journal Editors (ICMJE) since 2004. Methods: The 585 randomized controlled trials (RCTs) published between 1965 and 2017 that were included in a recently published Cochrane review on antiemetic drugs for prevention of postoperative nausea and vomiting were selected. In a retrospective study, we assessed trial registration and selective outcome reporting by comparing study publications with their registered protocols according to the ‘Cochrane Risk of bias’ assessment tool 1.0. Results: In the Cochrane review, the first study which referred to a registered trial protocol was published in 2004. Of all 585 trials included in the Cochrane review, 334 RCTs were published in 2004 or later, of which only 22% (75/334) were registered. Among the registered trials, 36% (27/75) were pro- and 64% (48/75) were retrospectively registered. 41% (11/27) of the prospectively registered trials were free of selective outcome reporting bias, 22% (6/27) were incompletely registered and assessed as unclear risk, and 37% (10/27) were assessed as high risk. Major outcome discrepancies between registered and published high risk trials were a change from the registered primary to a published secondary outcome (32%), a new primary outcome (26%), and different outcome assessment times (26%). Among trials with high risk of selective outcome reporting 80% favoured at least one statistically significant result. Registered trials were assessed more often as ‘overall low risk of bias’ compared to non-registered trials (64% vs 28%). Conclusions: In 2017, 13 years after the ICMJE declared prospective protocol registration a necessity for reliable clinical studies, the frequency and quality of trial registration in the field of PONV is very poor. Selective outcome reporting reduces trustworthiness in findings of clinical trials. Investigators and clinicians should be aware that only following a properly registered protocol and transparently reporting of predefined outcomes, regardless of the direction and significance of the result, will ultimately strengthen the body of evidence in the field of PONV research in the future. KW - clinical trial KW - postoperative nausea and vomiting KW - selective outcome reporting KW - systematic review KW - trial registration Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265518 VL - 21 ER - TY - JOUR A1 - Weibel, Stephanie A1 - Pace, Nathan L. A1 - Schaefer, Maximilian S. A1 - Raj, Diana A1 - Schlesinger, Tobias A1 - Meybohm, Patrick A1 - Kienbaum, Peter A1 - Eberhart, Leopold H. J. A1 - Kranke, Peter T1 - Drugs for preventing postoperative nausea and vomiting in adults after general anesthesia: An abridged Cochrane network meta-analysis JF - Journal of Evidence-Based Medicine N2 - Objective In this abridged version of the recently published Cochrane review on antiemetic drugs, we summarize its most important findings and discuss the challenges and the time needed to prepare what is now the largest Cochrane review with network meta-analysis in terms of the number of included studies and pages in its full printed form. Methods We conducted a systematic review with network meta-analyses to compare and rank single antiemetic drugs and their combinations belonging to 5HT₃-, D₂-, NK₁-receptor antagonists, corticosteroids, antihistamines, and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anesthesia. Results 585 studies (97 516 participants) testing 44 single drugs and 51 drug combinations were included. The studies’ overall risk of bias was assessed as low in only 27% of the studies. In 282 studies, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared to placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single NK1 receptor antagonists were as effective as other drug combinations. Of the 10 effective single drugs, certainty of evidence was high for aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron, while moderate for fosaprepitant and droperidol. For serious adverse events (SAEs), any adverse event (AE), and drug-class specific side effects evidence for intervention effects was mostly not convincing. Conclusions There is high or moderate evidence for at least seven single drugs preventing postoperative vomiting. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation. KW - systematic review, KW - antiemetics KW - network meta-analysis KW - postoperative nausea and vomiting KW - vomiting Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259470 VL - 14 IS - 3 ER - TY - JOUR A1 - Schlesinger, Tobias A1 - Weibel, Stephanie A1 - Steinfeldt, Thorsten A1 - Sitter, Magdalena A1 - Meybohm, Patrick A1 - Kranke, Peter T1 - Intraoperative management of combined general anesthesia and thoracic epidural analgesia: A survey among German anesthetists JF - Acta Anaesthesiologica Scandinavica N2 - Background Evidence concerning combined general anesthesia (GA) and thoracic epidural analgesia (EA) is controversial and the procedure appears heterogeneous in clinical implementation. We aimed to gain an overview of different approaches and to unveil a suspected heterogeneity concerning the intraoperative management of combined GA and EA. Methods This was an anonymous survey among Members of the Scientific working group for regional anesthesia within the German Society of Anaesthesiology and Intensive Care Medicine (DGAI) conducted from February 2020 to August 2020. Results The response rate was 38%. The majority of participants were experienced anesthetists with high expertise for the specific regimen of combined GA and EA. Most participants establish EA in the sitting position (94%), prefer early epidural initiation (prior to skin incision: 80%; intraoperative: 14%) and administer ropivacaine (89%) in rather low concentrations (0.2%: 45%; 0.375%: 30%; 0.75%: 15%) mostly with an opioid (84%) in a bolus-based mode (95%). The majority reduce systemic opioid doses intraoperatively if EA works sufficiently (minimal systemic opioids: 58%; analgesia exclusively via EA: 34%). About 85% manage intraoperative EA insufficiency with systemic opioids, 52% try to escalate EA, and only 25% use non-opioids, e.g. intravenous ketamine or lidocaine. Conclusions Although, consensus seems to be present for several aspects (patient's position during epidural puncture, main epidural substance, application mode), there is considerable heterogeneity regarding systemic opioids, rescue strategies for insufficient EA, and hemodynamic management, which might explain inconsistent results of previous trials and meta-analyses. KW - analgesics KW - enhanced recovery after surgery KW - multimodal treatments KW - perioperative care KW - epidural analgesia Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-258286 VL - 65 IS - 10 ER - TY - JOUR A1 - Reis, Stefanie A1 - Popp, Maria A1 - Schmid, Benedikt A1 - Stegemann, Miriam A1 - Metzendorf, Maria-Inti A1 - Kranke, Peter A1 - Meybohm, Patrick A1 - Weibel, Stephanie T1 - Safety and efficacy of intermediate- and therapeutic-dose anticoagulation for hospitalised patients with COVID-19: a systematic review and meta-analysis JF - Journal of Clinical Medicine N2 - Background: COVID-19 patients are at high thrombotic risk. The safety and efficacy of different anticoagulation regimens in COVID-19 patients remain unclear. Methods: We searched for randomised controlled trials (RCTs) comparing intermediate- or therapeutic-dose anticoagulation to standard thromboprophylaxis in hospitalised patients with COVID-19 irrespective of disease severity. To assess efficacy and safety, we meta-analysed data for all-cause mortality, clinical status, thrombotic event or death, and major bleedings. Results: Eight RCTs, including 5580 patients, were identified, with two comparing intermediate- and six therapeutic-dose anticoagulation to standard thromboprophylaxis. Intermediate-dose anticoagulation may have little or no effect on any thrombotic event or death (RR 1.03, 95% CI 0.86–1.24), but may increase major bleedings (RR 1.48, 95% CI 0.53–4.15) in moderate to severe COVID-19 patients. Therapeutic-dose anticoagulation may decrease any thrombotic event or death in patients with moderate COVID-19 (RR 0.64, 95% CI 0.38–1.07), but may have little or no effect in patients with severe disease (RR 0.98, 95% CI 0.86–1.12). The risk of major bleedings may increase independent of disease severity (RR 1.78, 95% CI 1.15–2.74). Conclusions: Certainty of evidence is still low. Moderately affected COVID-19 patients may benefit from therapeutic-dose anticoagulation, but the risk for bleeding is increased. KW - anticoagulant therapy KW - coronavirus disease 2019 KW - thrombosis KW - bleeding KW - death Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-252285 SN - 2077-0383 VL - 11 IS - 1 ER - TY - JOUR A1 - Kober, Christina A1 - Rohn, Susanne A1 - Weibel, Stephanie A1 - Geissinger, Ulrike A1 - Chen, Nanhai G. A1 - Szalay, Aladar A. T1 - Microglia and astrocytes attenuate the replication of the oncolytic vaccinia virus LIVP 1.1.1 in murine GL261 gliomas by acting as vaccinia virus traps JF - Journal of Translational Medicine N2 - Background Oncolytic virotherapy is a novel approach for the treatment of glioblastoma multiforme (GBM) which is still a fatal disease. Pathologic features of GBM are characterized by the infiltration with microglia/macrophages and a strong interaction between immune- and glioma cells. The aim of this study was to determine the role of microglia and astrocytes for oncolytic vaccinia virus (VACV) therapy of GBM. Methods VACV LIVP 1.1.1 replication in C57BL/6 and \(Foxn1^{nu/nu}\) mice with and without GL261 gliomas was analyzed. Furthermore, immunohistochemical analysis of microglia and astrocytes was investigated in non-, mock-, and LIVP 1.1.1-infected orthotopic GL261 gliomas in C57BL/6 mice. In cell culture studies virus replication and virus-mediated cell death of GL261 glioma cells was examined, as well as in BV-2 microglia and IMA2.1 astrocytes with M1 or M2 phenotypes. Co-culture experiments between BV-2 and GL261 cells and apoptosis/necrosis studies were performed. Organotypic slice cultures with implanted GL261 tumor spheres were used as additional cell culture system. Results We discovered that orthotopic GL261 gliomas upon intracranial virus delivery did not support replication of LIVP 1.1.1, similar to VACV-infected brains without gliomas. In addition, recruitment of \(Iba1^+\) microglia and \(GFAP^+\) astrocytes to orthotopically implanted GL261 glioma sites occurred already without virus injection. GL261 cells in culture showed high virus replication, while replication in BV-2 and IMA2.1 cells was barely detectable. The reduced viral replication in BV-2 cells might be due to rapid VACV-induced apoptotic cell death. In BV-2 and IMA 2.1 cells with M1 phenotype a further reduction of virus progeny and virus-mediated cell death was detected. Application of BV-2 microglial cells with M1 phenotype onto organotypic slice cultures with implanted GL261 gliomas resulted in reduced infection of BV-2 cells, whereas GL261 cells were well infected. Conclusion Our results indicate that microglia and astrocytes, dependent on their activation state, may preferentially clear viral particles by immediate uptake after delivery. By acting as VACV traps they further reduce efficient virus infection of the tumor cells. These findings demonstrate that glia cells need to be taken into account for successful GBM therapy development. KW - GBM KW - tumor microenvironment KW - microglia KW - polarization KW - VACV KW - OSC KW - IMA2.1 KW - BV-2 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126517 VL - 13 IS - 216 ER - TY - JOUR A1 - Adelfinger, Marion A1 - Gentschev, Ivaylo A1 - de Guibert, Julio Grimm A1 - Weibel, Stephanie A1 - Langbein-Laugwitz, Johanna A1 - Härtl, Barbara A1 - Escobar, Hugo Murua A1 - Nolte, Ingo A1 - Chen, Nanhai G. A1 - Aguilar, Richard J. A1 - Yu, Yong A. A1 - Zhang, Qian A1 - Frentzen, Alexa A1 - Szalay, Aladar A. T1 - Evaluation of a New Recombinant Oncolytic Vaccinia Virus Strain GLV-5b451 for Feline Mammary Carcinoma Therapy JF - PLoS ONE N2 - Virotherapy on the basis of oncolytic vaccinia virus (VACV) infection is a promising approach for cancer therapy. In this study we describe the establishment of a new preclinical model of feline mammary carcinoma (FMC) using a recently established cancer cell line, DT09/06. In addition, we evaluated a recombinant vaccinia virus strain, GLV-5b451, expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as an oncolytic agent against FMC. Cell culture data demonstrate that GLV-5b451 virus efficiently infected, replicated in and destroyed DT09/06 cancer cells. In the selected xenografts of FMC, a single systemic administration of GLV-5b451 led to significant inhibition of tumor growth in comparison to untreated tumor-bearing mice. Furthermore, tumor-specific virus infection led to overproduction of functional scAb GLAF-2, which caused drastic reduction of intratumoral VEGF levels and inhibition of angiogenesis. In summary, here we have shown, for the first time, that the vaccinia virus strains and especially GLV-5b451 have great potential for effective treatment of FMC in animal model. KW - antibodies KW - cancer treatment KW - carcinomas KW - vaccinia virus KW - oncolytic viruses KW - viral replication KW - cell cultures KW - enzyme-linked immunoassays Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119387 VL - 9 IS - 8 ER - TY - JOUR A1 - Donat, Ulrike A1 - Rother, Juliane A1 - Schäfer, Simon A1 - Hess, Michael A1 - Härtl, Barbara A1 - Kober, Christina A1 - Langbein-Laugwitz, Johanna A1 - Stritzker, Jochen A1 - Chen, Nanhai G. A1 - Aguilar, Richard J. A1 - Weibel, Stephanie A1 - Szalay, Alandar A. T1 - Characterization of Metastasis Formation and Virotherapy in the Human C33A Cervical Cancer Model JF - PLoS ONE N2 - More than 90% of cancer mortalities are due to cancer that has metastasized. Therefore, it is crucial to intensify research on metastasis formation and therapy. Here, we describe for the first time the metastasizing ability of the human cervical cancer cell line C33A in athymic nude mice after subcutaneous implantation of tumor cells. In this model, we demonstrated a steady progression of lumbar and renal lymph node metastases during tumor development. Besides predominantly occurring lymphatic metastases, we visualized the formation of hematogenous metastases utilizing red fluorescent protein (RFP) expressing C33A-RFP cells. RFP positive cancer cells were found migrating in blood vessels and forming micrometastases in lungs of tumor-bearing mice. Next, we set out to analyze the influence of oncolytic virotherapy in the C33A-RFP model and demonstrated an efficient virus-mediated reduction of tumor size and metastatic burden. These results suggest the C33A-RFP cervical cancer model as a new platform to analyze cancer metastases as well as to test novel treatment options to combat metastases. KW - metastasis KW - renal cancer KW - oncolytic viruses KW - lymph nodes KW - kidneys KW - lung and intrathoracic tumors KW - secondary lung tumors KW - cancer treatment Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119674 SN - 1932-6203 VL - 9 IS - 6 ER -