@article{WeibelPoppReisetal.2023, author = {Weibel, Stephanie and Popp, Maria and Reis, Stefanie and Skoetz, Nicole and Garner, Paul and Sydenham, Emma}, title = {Identifying and managing problematic trials: A research integrity assessment tool for randomized controlled trials in evidence synthesis}, series = {Research Synthesis Methods}, volume = {14}, journal = {Research Synthesis Methods}, number = {3}, doi = {10.1002/jrsm.1599}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318236}, pages = {357 -- 369}, year = {2023}, abstract = {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.}, language = {en} } @article{HackenbroichKrankeMeybohmetal.2022, author = {Hackenbroich, Samantha and Kranke, Peter and Meybohm, Patrick and Weibel, Stephanie}, title = {Include or not to include conference abstracts in systematic reviews? Lessons learned from a large Cochrane network meta-analysis including 585 trials}, series = {Systematic Reviews}, volume = {11}, journal = {Systematic Reviews}, number = {1}, doi = {10.1186/s13643-022-02048-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299660}, year = {2022}, abstract = {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.}, language = {en} } @article{SchmidGrieselFischeretal.2022, author = {Schmid, Benedikt and Griesel, Mirko and Fischer, Anna-Lena and Romero, Carolina S. and Metzendorf, Maria-Inti and Weibel, Stephanie and Fichtner, Falk}, title = {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}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {2}, issn = {2077-0383}, doi = {10.3390/jcm11020391}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255225}, year = {2022}, abstract = {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.}, language = {en} } @article{ReisPoppSchmidetal.2021, author = {Reis, Stefanie and Popp, Maria and Schmid, Benedikt and Stegemann, Miriam and Metzendorf, Maria-Inti and Kranke, Peter and Meybohm, Patrick and Weibel, Stephanie}, title = {Safety and efficacy of intermediate- and therapeutic-dose anticoagulation for hospitalised patients with COVID-19: a systematic review and meta-analysis}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {1}, issn = {2077-0383}, doi = {10.3390/jcm11010057}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252285}, year = {2021}, abstract = {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.}, language = {en} } @article{RiemerKrankeHelfetal.2021, author = {Riemer, Manuel and Kranke, Peter and Helf, Antonia and Mayer, Debora and Popp, Maria and Schlesinger, Tobias and Meybohm, Patrick and Weibel, Stephanie}, title = {Trial registration and selective outcome reporting in 585 clinical trials investigating drugs for prevention of postoperative nausea and vomiting}, series = {BMC Anesthesiology}, volume = {21}, journal = {BMC Anesthesiology}, doi = {10.1186/s12871-021-01464-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265518}, year = {2021}, abstract = {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.}, language = {en} } @article{WeibelPaceSchaeferetal.2021, author = {Weibel, Stephanie and Pace, Nathan L. and Schaefer, Maximilian S. and Raj, Diana and Schlesinger, Tobias and Meybohm, Patrick and Kienbaum, Peter and Eberhart, Leopold H. J. and Kranke, Peter}, title = {Drugs for preventing postoperative nausea and vomiting in adults after general anesthesia: An abridged Cochrane network meta-analysis}, series = {Journal of Evidence-Based Medicine}, volume = {14}, journal = {Journal of Evidence-Based Medicine}, number = {3}, doi = {10.1111/jebm.12429}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259470}, pages = {188-197}, year = {2021}, abstract = {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.}, language = {en} } @article{SchlesingerWeibelSteinfeldtetal.2021, author = {Schlesinger, Tobias and Weibel, Stephanie and Steinfeldt, Thorsten and Sitter, Magdalena and Meybohm, Patrick and Kranke, Peter}, title = {Intraoperative management of combined general anesthesia and thoracic epidural analgesia: A survey among German anesthetists}, series = {Acta Anaesthesiologica Scandinavica}, volume = {65}, journal = {Acta Anaesthesiologica Scandinavica}, number = {10}, doi = {10.1111/aas.13971}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258286}, pages = {1490-1496}, year = {2021}, abstract = {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.}, language = {en} } @article{GentschevMuellerAdelfingeretal.2011, author = {Gentschev, Ivaylo and M{\"u}ller, Meike and Adelfinger, Marion and Weibel, Stephanie and Grummt, Friedrich and Zimmermann, Martina and Bitzer, Michael and Heisig, Martin and Zhang, Qian and Yu, Yong A. and Chen, Nanhai G. and Stritzker, Jochen and Lauer, Ulrich M. and Szalay, Aladar A.}, title = {Efficient Colonization and Therapy of Human Hepatocellular Carcinoma (HCC) Using the Oncolytic Vaccinia Virus Strain GLV-1h68}, series = {PLOS ONE}, volume = {6}, journal = {PLOS ONE}, number = {7}, doi = {10.1371/journal.pone.0022069}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135319}, pages = {e22069}, year = {2011}, abstract = {Virotherapy using oncolytic vaccinia virus strains is one of the most promising new strategies for cancer therapy. In this study, we analyzed for the first time the therapeutic efficacy of the oncolytic vaccinia virus GLV-1h68 in two human hepatocellular carcinoma cell lines HuH7 and PLC/PRF/5 (PLC) in cell culture and in tumor xenograft models. By viral proliferation assays and cell survival tests, we demonstrated that GLV-1h68 efficiently colonized, replicated in, and did lyse these cancer cells in culture. Experiments with HuH7 and PLC xenografts have revealed that a single intravenous injection (i.v.) of mice with GLV-1h68 resulted in a significant reduction of primary tumor sizes compared to uninjected controls. In addition, replication of GLV-1h68 in tumor cells led to strong inflammatory and oncolytic effects resulting in intense infiltration of MHC class II-positive cells like neutrophils, macrophages, B cells and dendritic cells and in up-regulation of 13 pro-inflammatory cytokines. Furthermore, GLV-1h68 infection of PLC tumors inhibited the formation of hemorrhagic structures which occur naturally in PLC tumors. Interestingly, we found a strongly reduced vascular density in infected PLC tumors only, but not in the non-hemorrhagic HuH7 tumor model. These data demonstrate that the GLV-1h68 vaccinia virus may have an enormous potential for treatment of human hepatocellular carcinoma in man.}, language = {en} } @article{SchaeferWeibelDonatetal.2012, author = {Sch{\"a}fer, Simon and Weibel, Stephanie and Donat, Ulrike and Zhang, Quian and Aguilar, Richard J. and Chen, Nanhai G. and Szalay, Aladar A.}, title = {Vaccinia virus-mediated intra-tumoral expression of matrix metalloproteinase 9 enhances oncolysis of PC-3 xenograft tumors}, series = {BMC Cancer}, volume = {12}, journal = {BMC Cancer}, number = {366}, doi = {10.1186/1471-2407-12-366}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140800}, year = {2012}, abstract = {Background Oncolytic viruses, including vaccinia virus (VACV), are a promising alternative to classical mono-cancer treatment methods such as surgery, chemo- or radiotherapy. However, combined therapeutic modalities may be more effective than mono-therapies. In this study, we enhanced the effectiveness of oncolytic virotherapy by matrix metalloproteinase (MMP-9)-mediated degradation of proteins of the tumoral extracellular matrix (ECM), leading to increased viral distribution within the tumors. Methods For this study, the oncolytic vaccinia virus GLV-1h255, containing the mmp-9 gene, was constructed and used to treat PC-3 tumor-bearing mice, achieving an intra-tumoral over-expression of MMP-9. The intra-tumoral MMP-9 content was quantified by immunohistochemistry in tumor sections. Therapeutic efficacy of GLV-1h255 was evaluated by monitoring tumor growth kinetics and intra-tumoral virus titers. Microenvironmental changes mediated by the intra-tumoral MMP-9 over-expression were investigated by microscopic quantification of the collagen IV content, the blood vessel density (BVD) and the analysis of lymph node metastasis formation. Results GLV-1h255-treatment of PC-3 tumors led to a significant over-expression of intra-tumoral MMP-9, accompanied by a marked decrease in collagen IV content in infected tumor areas, when compared to GLV-1h68-infected tumor areas. This led to considerably elevated virus titers in GLV-1h255 infected tumors, and to enhanced tumor regression. The analysis of the BVD, as well as the lumbar and renal lymph node volumes, revealed lower BVD and significantly smaller lymph nodes in both GLV-1h68- and GLV-1h255- injected mice compared to those injected with PBS, indicating that MMP-9 over-expression does not alter the metastasis-reducing effect of oncolytic VACV. Conclusions Taken together, these results indicate that a GLV-1h255-mediated intra-tumoral over-expression of MMP-9 leads to a degradation of collagen IV, facilitating intra-tumoral viral dissemination, and resulting in accelerated tumor regression. We propose that approaches which enhance the oncolytic effect by increasing the intra-tumoral viral load, may be an effective way to improve therapeutic outcome.}, language = {en} } @article{PatilGentschevAdelfingeretal.2012, author = {Patil, Sandeep S. and Gentschev, Ivaylo and Adelfinger, Marion and Donat, Ulrike and Hess, Michael and Weibel, Stephanie and Nolte, Ingo and Frentzen, Alexa and Szalay, Aladar A.}, title = {Virotherapy of Canine Tumors with Oncolytic Vaccinia Virus GLV-1h109 Expressing an Anti-VEGF Single-Chain Antibody}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047472}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130039}, pages = {e47472}, year = {2012}, abstract = {Virotherapy using oncolytic vaccinia virus (VACV) strains is one promising new strategy for cancer therapy. We have previously reported that oncolytic vaccinia virus strains expressing an anti-VEGF (Vascular Endothelial Growth Factor) single-chain antibody (scAb) GLAF-1 exhibited significant therapeutic efficacy for treatment of human tumor xenografts. Here, we describe the use of oncolytic vaccinia virus GLV-1h109 encoding GLAF-1 for canine cancer therapy. In this study we analyzed the virus-mediated delivery and production of scAb GLAF-1 and the oncolytic and immunological effects of the GLV-1h109 vaccinia virus strain against canine soft tissue sarcoma and canine prostate carcinoma in xenograft models. Cell culture data demonstrated that the GLV-1h109 virus efficiently infect, replicate in and destroy both tested canine cancer cell lines. In addition, successful expression of GLAF-1 was demonstrated in virus-infected canine cancer cells and the antibody specifically recognized canine VEGF. In two different xenograft models, the systemic administration of the GLV-1h109 virus was found to be safe and led to anti-tumor and immunological effects resulting in the significant reduction of tumor growth in comparison to untreated control mice. Furthermore, tumor-specific virus infection led to a continued production of functional scAb GLAF-1, resulting in inhibition of angiogenesis. Overall, the GLV-1h109-mediated cancer therapy and production of immunotherapeutic anti-VEGF scAb may open the way for combination therapy concept i.e. vaccinia virus mediated oncolysis and intratumoral production of therapeutic drugs in canine cancer patients.}, language = {en} }