69 research outputs found

    Systematic review about data quality and protocol compliance in clinical trials

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    Bei Investigator Initiated Trials (IITs) werden alternative risikoadaptierte Monitoring-Strategien in Abhängigkeit vom individuellen Studiendesign und dem Risikoprofil diskutiert, um bei oft restriktiven Ressourcen eine den gesetzlichen Vorgaben genügende Qualität der Studiendurchführung und der Daten zu gewährleisten. Aufgrund einer Literaturanalyse sollten in der vorliegenden Arbeit Untersuchungen ausgewertet werden, in denen quantitative Aussagen zu Datenqualität und Prüfplan-Compliance in klinischen Prüfungen gemacht wurden. Bei der Interpretation der Ergebnisse sollten die implementierten Qualitätssicherungsmaßnahmen berücksichtigt werden. Aufgrund einer systematischen Recherche in MEDLINE konnten 21 Publikationen identifiziert werden, bei denen die Daten- und Prozessqualität in klinischen Prüfungen untersucht, die Qualität durch Überprüfungen mit Source Data Verification vor Ort oder Überprüfung übermittelter Quelldaten in der Studienzentrale ermittelt wurde und quantitative Informationen zu den Bereichen Datenqualität, Protokoll-Compliance oder Defizite bei Einwilligungserklärungen vorlagen. Die Mehrzahl der Untersuchungen ist drei Organisationen zuzuordnen: European Organization für Research and Treatment of Cancer (EORTC) (n=7), National Cancer Institute (NCI) (n=7) und Untersuchungen der Trans-Tasman Radiation Oncology Group (TROG) (n=4). Darüber hinaus wurden drei Untersuchungen weiterer Studiengruppen identifiziert. Die Untersuchungen wurden im Zeitraum von 1981 bis 2003 publiziert. Überwiegend wurden in der Literatur onkologische Studien betrachtet (n=19), wobei die Radiotherapie im Vordergrund stand (n=8). Für die EORTC-Studien wurde in der Regel eine gute Datenqualität berichtet (80-90% korrekte Daten). Punktuelle Probleme wurden im Hinblick auf die Protokoll-Compliance und das Berichten von Nebenwirkungen/schwerwiegenden unerwünschten Ereignissen festgestellt. Eine gute Qualität wurde ebenfalls bzgl. des korrekten Einschlusses von Patienten beobachtet. Durch das NCI wurde ein standardisiertes Audit-System eingeführt und innerhalb von kooperativen Studiengruppen implementiert. Im Rahmen dieser Audits wurden verschiedene Kriterien überprüft und eine überwiegend gute Datenqualität und Protokoll-Compliance festgestellt. Mängel wurden in ca. 5% der Fälle im Hinblick auf die Einwilligungserklärung, die korrekte Anwendung der Einschlusskriterien, Protokollverletzungen, bei der Ermittlung des Zielkriteriums, der Erfassung der Toxizität, der adäquaten Datenlieferung und bei der Datenverifikation beobachtet. In einzelnen Untersuchungen ergaben sich Probleme mit der Behandlungscompliance (10-20%), bei Protokollabweichungen im Hinblick auf die Arzneimitteldosis (10%) und bei der Drug Accountability (15%). Von der TROG wurde ein Qualitätssicherungsprozess implementiert, der auf zentralem Monitoring von kopierten Quelldaten basiert. Durch den Qualitätssicherungsansatz der TROG konnten schwerwiegende Probleme mit der Protokoll-Compliance unter 10% gesenkt werden, ebenso konnte eine gute Datenqualität mit einer Fehlerrate unter 5% erreicht werden. Die korrekte Handhabung von Ein- und Ausschlusskriterien stellte in Einzelfällen ein Problem dar. Zusammenfassend kann festgestellt werden, dass die in dem Review erfassten Studiengruppen von einer guten Datenqualität und einer guten bis moderaten Protokoll-Compliance berichten. Diese basiert nach Aussage der Autoren im wesentlichen auf etablierten Qualitätssicherungs-Prozeduren, wobei das durchgeführte Audit ebenfalls einen potentiellen Einflussfaktor darstellt. Geringe Probleme wurden in der Regel im Hinblick auf die Einwilligungserklärung, die korrekte Handhabung der Ein- und Ausschlusskriterien und die Datenqualität beobachtet. In einzelnen Studien gab es jedoch Probleme mit der Protokoll-Compliance. Insgesamt hängen Anzahl und Art der Mängel von dem Studientyp, dem Qualitätsmanagement und der Organisation der Studiengruppe ab. Wissenschaftsbetrug wurde nur in sehr wenigen Fällen durch die Audits festgestellt. Die vorgelegten Informationen beziehen sich nahezu ausschließlich auf etablierte Studiengruppen; bezüglich Datenqualität und Protokoll-Compliance außerhalb der Studiengruppen liegen kaum Informationen in der Literatur vor. Bei der Bewertung der Ergebnisse sollte berücksichtigt werden, dass es sich zum Teil um Eigenauswertungen der Studiengruppen und nicht um unabhängige externe Prüfungen (z.B. externe Audits) handelt. Inwieweit die Ergebnisse einer konsequenten Überprüfung nach derzeitigen Good Clinical Practice (GCP) – Regeln standhalten würden, kann aus der Analyse nicht beantwortet werden. Aus der vorliegenden Literaturanalyse ergeben sich Konsequenzen für die Planung einer prospektiven kontrollierten Studie zum Vergleich unterschiedlicher Monitoring-Strategien. Wesentlicher Einflussfaktor für die Datenqualität und Protokollcompliance in einer klinischen Studie ist das Qualitätsmanagement. Dieses Qualitätsmanagement umfasst neben Monitoring zahlreiche andere Maßnahmen. Um zu einer Bewertung von Monitoringstrategien kommen zu können, müssen daher alle Qualitätssicherungsmaßnahmen im Rahmen einer Studie berücksichtigt werden. Für den Vergleich unterschiedlicher Monitoringstrategien sind geeignete Zielparameter zu definieren (z.B. schwerwiegende Defizite bzgl. Ein- und Ausschlusskriterien, Sicherheit). Die vorliegende Analyse ergibt, dass bei gutem Qualitätsmanagement ohne umfassendes vor Ort Monitoring schwerwiegende Fehler nur mit relativ niedriger Häufigkeit festgestellt wurden. Unterschiede zwischen Monitoringstrategien könnten, gegeben ein funktionierendes Qualitätsmanagementssystem, sich als quantitativ gering erweisen. Testet man auf Äquivalenz von Monitoringstrategien, sind nur niedrige Differenzen zu akzeptieren, was wiederum eine Auswirkung auf die Fallzahlplanung hat. Weiterhin muss berücksichtigt werden, dass zur Feststellung der Auswirkung unterschiedlicher Monitoringstrategien auf die Sicherheit der Patienten und die Validität der Daten im Rahmen einer kontrollierten Untersuchung ein unabhängiges Audit notwendig ist. Dabei ist zu berücksichtigen, dass ein Audit bereits einen möglichen Einflussfaktor für die Datenqualität und Protokoll-Compliance darstellen kann, und damit eine Bewertung des Nutzens einer Monitoringstrategie erschwert werden könnte. Schlüsselwörter: systematisches Review, Datenqualität, Protokoll-Compliance, klinische StudieFor Investigator Initiated Trials (IITs) alternative risk-adapted monitoring strategies are discussed in order to fulfill rules and regulations, taking into consideration the restricted resources. In this systematic review investigations, presenting quantitative data about data quality and protocol compliance in clinical trials, are analyzed. The results are discussed taking into account the quality assurance procedures implemented. Based on a systematic MEDLINE retrieval, 21 studies could be identified in which data and process quality in clinical trials were investigated and assessed by site visits with source data verification or review of copied source data in the study center and quantitative information about data quality and protocol compliance was available. The majority of investigations were performed by three organizations: European Organization for Research and Treatment of Cancer (EORTC) (n=7), National Cancer Institute (NCI) (n=7) and investigations of the Trans-Tasman Radiation Oncology Group (TROG) (n=4). In addition three investigations of other study groups were identified. The investigations were published between 1981 and 2003. In the majority of cases oncological trials were investigated (n=19) with a focus on radiotherapy trials (n=8). In the EORTC-trials an overall good data quality was assessed (80–90% correct data). Singular problems were found with respect to protocol compliance and reporting of adverse reactions and serious unexpected events. Good quality was also observed with respect to the correct inclusion of patients into trials. By the NCI a standardized audit system was introduced and implemented within cooperative study groups. In the context of these audits different criteria were assessed and a good data quality and protocol compliance were measured. Deficits occurred in about 5% of the cases with respect to informed consent, correct application of inclusion criteria, protocol compliance, assessment of outcome criteria, assessment of toxicity, adequate data reporting and data verification. In some investigations problems with treatment compliance (10-20%), drug dose deviations (10%) and drug accountability (15%) were identified. By the TROG a quality assurance procedure was implemented, based on central monitoring of copied source data. By this approach major problems with protocol compliance could be reduced to less than 10% together with a good data quality with an error rate under 5%. The correct handling of in- and exclusion criteria was a problem in individual cases. In summary we found out that good data quality and good to moderate protocol compliance were reported by the study groups that are included in the systematic review. Due to the authors this is mainly due to an established quality assurance system, taking into consideration that audits itself may be an influential factor. Generally, minor problems were observed with respect to informed consent, correct handling of in- and exclusion criteria and data quality, however, in some studies there were problems with protocol compliance. Overall, number and type of deficits depend on study type, quality management and organization of the study group. Fraud was detected only in very few cases. The available evidence refers mainly to established study groups; for data quality and protocol compliance outside these groups only few information is available. However, it should be taken into consideration, that the analysis was performed, at least partly, by the study groups themselves and is not based on independent audits (e.g. external audits). The analysis cannot answer the question whether the results would have been replicable if a strict review according to criteria of Good Clinical Practice (GCP) would have been performed. From the systematic review consequences have to be taken for planning a prospective controlled trial comparing different monitoring strategies. The main influence factor for data quality and protocol compliance in a clinical trial is the quality management system. Quality management covers several other measures apart from monitoring. In order to assess monitoring strategies, all quality assurance procedures within a clinical trial have to be taken into consideration. For the comparison of different monitoring strategies adequate outcome parameter have to be defined (e.g. severe deficits with respect to inclusion and exclusion criteria, safety). The analysis indicates that with good quality management and no extensive on-site monitoring severe errors were detected only at relative low frequency. It could well be that with an efficient quality management system differences between monitoring strategies would be small. In order to demonstrate statistical equivalence of monitoring strategies, only small differences can be accepted which again leads to consequences for the sample-size calculation. In addition, it must be taken into consideration that within a controlled trial an independent audit is necessary to assess the effect of different monitoring strategies on the safety of patients and the quality of data. Audits however may be a possible influence factor for data quality and protocol compliance and may complicate the evaluation of the benefit of a monitoring strategy. Keywords: systematic review, data quality, protocol compliance, clinical tria

    Early oral switch therapy in low-risk Staphylococcus aureus bloodstream infection (SABATO): study protocol for a randomized controlled trial

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    Background Current guidelines recommend that patients with Staphylococcus aureus bloodstream infection (SAB) are treated with long courses of intravenous antimicrobial therapy. This serves to avoid SAB-related complications such as relapses, local extension and distant metastatic foci. However, in certain clinical scenarios, the incidence of SAB-related complications is low. Patients with a low-risk for complications may thus benefit from an early switch to oral medication through earlier discharge and fewer complications of intravenous therapy. The major objective for the SABATO trial is to demonstrate that in patients with low-risk SAB a switch from intravenous to oral antimicrobial therapy (oral switch therapy, OST) is non-inferior to a conventional course of intravenous therapy (intravenous standard therapy, IST). Methods/Design The trial is designed as randomized, parallel-group, observer-blinded, clinical non-inferiority trial. The primary endpoint is the occurrence of a SAB-related complication (relapsing SAB, deep-seated infection, and attributable mortality) within 90 days. Secondary endpoints are the length of hospital stay; 14-day, 30-day, and 90-day mortality; and complications of intravenous therapy. Patients with SAB who have received 5 to 7 full days of adequate intravenous antimicrobial therapy are eligible. Main exclusion criteria are polymicrobial bloodstream infection, signs and symptoms of complicated SAB (deep-seated infection, hematogenous dissemination, septic shock, and prolonged bacteremia), the presence of a non-removable foreign body, and severe comorbidity. Patients will receive either OST or IST with a protocol-approved antimicrobial and are followed up for 90 days. Four hundred thirty patients will be randomized 1:1 in two study arms. Efficacy regarding incidence of SAB-related complications is tested sequentially with a non-inferiority margin of 10 and 5 percentage points. Discussion The SABATO trial assesses whether early oral switch therapy is safe and effective for patients with low-risk SAB. Regardless of the result, this pragmatic trial will strongly influence the standard of care in SAB. Trial registration ClinicalTrials.gov NCT01792804 registered 13 February 2013; German Clinical trials register DRKS00004741 registered 4 October 2013, EudraCT 2013-000577-77. First patient randomized on 20 December 2013

    Use of vitamin K antagonists for secondary stroke prevention depends on the treating healthcare provider in Germany – results from the German AFNET registry

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    Background Anticoagulation using vitamin K antagonists (VKAs) significantly reduces the risk of recurrent stroke in stroke patients with atrial fibrillation (AF) and is recommended by guidelines. Methods The German Competence NETwork on Atrial Fibrillation established a nationwide prospective registry including 9,574 AF patients, providing the opportunity to analyse AF management according to German healthcare providers. Results On enrolment, 896 (9.4 %) patients reported a prior ischaemic stroke or transient ischaemic attack. Stroke patients were significantly older, more likely to be female, had a higher rate of cardiovascular risk factors, and more frequently received anticoagulation (almost exclusively VKA) than patients without prior stroke history. Following enrolment, 76.4 % of all stroke patients without VKA contraindications received anticoagulation, which inversely associated with age (OR 0.95 per year; 95 % CI 0.92–0.97). General practitioners/internists (OR 0.40; 95 % CI 0.21–0.77) and physicians working in regional hospitals (OR 0.47; 95 % CI 0.29–0.77) prescribed anticoagulation for secondary stroke prevention less frequently than physicians working at university hospitals (reference) and office-based cardiologists (OR 1.40; 95 % CI 0.76–2.60). The impact of the treating healthcare provider was less evident in registry patients without prior stroke. Conclusions In the AFNET registry, anticoagulation for secondary stroke prevention was prescribed in roughly three-quarters of AF patients, a significantly higher rate than in primary prevention. We identified two factors associated with withholding oral anticoagulation in stroke survivors, namely higher age and—most prominently—treatment by a general practitioner/internist or physicians working at regional hospitals

    The European Network for Translational Research in Atrial Fibrillation (EUTRAF): objectives and initial results

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    Atrial fibrillation (AF) is the most common sustained arrhythmia in the general population. As an age-related arrhythmia AF is becoming a huge socio-economic burden for European healthcare systems. Despite significant progress in our understanding of the pathophysiology of AF, therapeutic strategies for AF have not changed substantially and the major challenges in the management of AF are still unmet. This lack of progress may be related to the multifactorial pathogenesis of atrial remodelling and AF that hampers the identification of causative pathophysiological alterations in individual patients. Also, again new mechanisms have been identified and the relative contribution of these mechanisms still has to be established. In November 2010, the European Union launched the large collaborative project EUTRAF (European Network of Translational Research in Atrial Fibrillation) to address these challenges. The main aims of EUTRAF are to study the main mechanisms of initiation and perpetuation of AF, to identify the molecular alterations underlying atrial remodelling, to develop markers allowing to monitor this processes, and suggest strategies to treat AF based on insights in newly defined disease mechanisms. This article reports on the objectives, the structure, and initial results of this networ

    DNA methylation-based classification of sinonasal tumors

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    The diagnosis of sinonasal tumors is challenging due to a heterogeneous spectrum of various differential diagnoses as well as poorly defined, disputed entities such as sinonasal undifferentiated carcinomas (SNUCs). In this study, we apply a machine learning algorithm based on DNA methylation patterns to classify sinonasal tumors with clinical-grade reliability. We further show that sinonasal tumors with SNUC morphology are not as undifferentiated as their current terminology suggests but rather reassigned to four distinct molecular classes defined by epigenetic, mutational and proteomic profiles. This includes two classes with neuroendocrine differentiation, characterized by IDH2 or SMARCA4/ARID1A mutations with an overall favorable clinical course, one class composed of highly aggressive SMARCB1-deficient carcinomas and another class with tumors that represent potentially previously misclassified adenoid cystic carcinomas. Our findings can aid in improving the diagnostic classification of sinonasal tumors and could help to change the current perception of SNUCs

    Mitochondrial Control Region and microsatellite analyses on harbour porpoise (Phocoena phocoena) unravel population differentiation in the Baltic Sea and adjacent waters

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    The population status of the harbour porpoise (Phocoena phocoena) in the Baltic area has been a continuous matter of debate. Here we present the by far most comprehensive genetic population structure assessment to date for this region, both with regard to geographic coverage and sample size: 497 porpoise samples from North Sea, Skagerrak, Kattegat, Belt Sea, and Inner Baltic Sea were sequenced at the mitochondrial Control Region and 305 of these specimens were typed at 15 polymorphic microsatellite loci. Samples were stratified according to sample type (stranding vs. by-caught), sex, and season (breeding vs. non-breeding season). Our data provide ample evidence for a population split between the Skagerrak and the Belt Sea, with a transition zone in the Kattegat area. Among other measures, this was particularly visible in significant frequency shifts of the most abundant mitochondrial haplotypes. A particular haplotype almost absent in the North Sea was the most abundant in Belt Sea and Inner Baltic Sea. Microsatellites yielded a similar pattern (i.e., turnover in occurrence of clusters identified by STRUCTURE). Moreover, a highly significant association between microsatellite assignment and unlinked mitochondrial haplotypes further indicates a split between North Sea and Baltic porpoises. For the Inner Baltic Sea, we consistently recovered a small, but significant separation from the Belt Sea population. Despite recent arguments that separation should exceed a predefined threshold before populations shall be managed separately, we argue in favour of precautionary acknowledging the Inner Baltic porpoises as a separate management unit, which should receive particular attention, as it is threatened by various factors, in particular local fishery measures. © Springer Science+Business Media B.V. 2009
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