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Martina Felder - One of the best experts on this subject based on the ideXlab platform.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that β-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P = .02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P = .20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P = .13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P = .29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that beta-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P =.02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P =.20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P =.13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P =.29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

Carlo Merkel - One of the best experts on this subject based on the ideXlab platform.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that β-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P = .02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P = .20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P = .13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P = .29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that beta-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P =.02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P =.20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P =.13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P =.29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

Rene Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • on variance estimation for the one sample Log Rank Test
    arXiv: Methodology, 2021
    Co-Authors: Moritz Fabian Danzer, Andreas Faldum, Rene Schmidt
    Abstract:

    Time-to-event endpoints show an increasing popularity in phase II cancer trials. The standard statistical tool for such endpoints in one-armed trials is the one-sample Log-Rank Test. It is widely known, that the asymptotic providing the correctness of this Test does not come into effect to full extent for small sample sizes. There have already been some attempts to solve this problem. While some do not allow easy power and sample size calculations, others lack a clear theoretical motivation and require further considerations. The problem itself can partly be attributed to the dependence of the compensated counting process and its variance estimator. We provide a framework in which the variance estimator can be flexibly adopted to the present situation while maintaining its asymptotical properties. We exemplarily suggest a variance estimator which is uncorrelated to the compensated counting process. Furthermore, we provide sample size and power calculations for any approach fitting into our framework. Finally, we compare several methods via simulation studies and the hypothetical setup of a Phase II trial based on real world data.

  • an improved one sample Log Rank Test
    Statistical Methods in Medical Research, 2020
    Co-Authors: Laura Kerschke, Andreas Faldum, Rene Schmidt
    Abstract:

    The one-sample Log-Rank Test allows to compare the survival of a single sample with a prefixed reference survival curve. It naturally applies in single-arm phase IIa trials with time-to-event endpoint. Several authors have described that the original one-sample Log-Rank Test is conservative when sample size is small and have proposed strategies to correct the conservativeness. Here, we propose an alternative approach to improve the one-sample Log-Rank Test. Our new one-sample Log-Rank statistic is based on the unique transformation of the underlying counting process martingale such that the moments of the limiting normal distribution have no shared parameters. Simulation results show that the new one-sample Log-Rank Test gives type I error rate and power close to the nominal levels also when sample size is small, while relevantly reducing the required sample size to achieve the desired power as compared to current approaches to design studies to compare the survival outcome of a sample with a reference.

  • adaptive designs for the one sample Log Rank Test
    Biometrics, 2018
    Co-Authors: Rene Schmidt, Andreas Faldum, Robert Kwiecien
    Abstract:

    Summary Traditional designs in phase IIa cancer trials are single-arm designs with a binary outcome, for example, tumor response. In some settings, however, a time-to-event endpoint might appear more appropriate, particularly in the presence of loss to follow-up. Then the one-sample Log-Rank Test might be the method of choice. It allows to compare the survival curve of the patients under treatment to a prespecified reference survival curve. The reference curve usually represents the expected survival under standard of the care. In this work, convergence of the one-sample Log-Rank statistic to Brownian motion is proven using Rebolledo's martingale central limit theorem while accounting for staggered entry times of the patients. On this basis, a confirmatory adaptive one-sample Log-Rank Test is proposed where provision is made for data dependent sample size reassessment. The focus is to apply the inverse normal method. This is done in two different directions. The first strategy exploits the independent increments property of the one-sample Log-Rank statistic. The second strategy is based on the patient-wise separation principle. It is shown by simulation that the proposed adaptive Test might help to rescue an underpowered trial and at the same time lowers the average sample number (ASN) under the null hypothesis as compared to a single-stage fixed sample design.

  • sample size calculation for the one sample Log Rank Test
    Statistics in Medicine, 2015
    Co-Authors: Rene Schmidt, Robert Kwiecien, Andreas Faldum, Frank Berthold, Barbara Hero, Sandra Ligges
    Abstract:

    An improved method of sample size calculation for the one-sample Log-Rank Test is provided. The one-sample Log-Rank Test may be the method of choice if the survival curve of a single treatment group is to be compared with that of a historic control. Such settings arise, for example, in clinical phase-II trials if the response to a new treatment is measured by a survival endpoint. Present sample size formulas for the one-sample Log-Rank Test are based on the number of events to be observed, that is, in order to achieve approximately a desired power for allocated significance level and effect the trial is stopped as soon as a certain critical number of events are reached. We propose a new stopping criterion to be followed. Both approaches are shown to be asymptotically equivalent. For small sample size, though, a simulation study indicates that the new criterion might be preferred when planning a corresponding trial. In our simulations, the trial is usually underpowered, and the aspired significance level is not exploited if the traditional stopping criterion based on the number of events is used, whereas a trial based on the new stopping criterion maintains power with the type-I error rate still controlled.

Iebin Lian - One of the best experts on this subject based on the ideXlab platform.

R. Marin - One of the best experts on this subject based on the ideXlab platform.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that β-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P = .02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P = .20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P = .13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P = .29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

  • long term results of a clinical trial of nadolol with or without isosorbide mononitrate for primary prophylaxis of variceal bleeding in cirrhosis
    Hepatology, 2000
    Co-Authors: Carlo Merkel, Carole Donada, Giorgio Cavallarin, Pierluigi Torboli, Giuliana Sebastianelli, Massimo Bolognesi, R. Marin, Piero Amodio, David Sacerdoti, Martina Felder
    Abstract:

    It is clearly established that beta-blockers decrease the risk of a first variceal bleeding in cirrhosis. We have recently shown that the addition of isosorbide mononitrate to nadolol decreases the rate of variceal bleeding in patients with cirrhosis and varices, compared with nadolol alone, after a median follow-up of 30 months. It is not established if the long-term treatment with the combination continues to be beneficial. Therefore, we assessed the long-term effect of this combination on first variceal bleeding, complications, and death. One hundred forty-six cirrhotic patients with esophageal varices included in a previously published multicenter, randomized study comparing nadolol (40-160 mg/d) with the combination nadolol plus isosorbide mononitrate (10-20 mg 3 times per day) were followed up for up to 7 years (median follow-up, 55 months). The primary end-point was variceal bleeding of any severity. Twenty-four patients (16 in the nadolol group, and 8 in the combination group) experienced variceal bleeding (Log Rank Test, P =.02). Cumulative risk of bleeding was 29% and 12%, respectively (95% CI for the difference, 1%-23%). Two and 4 patients, respectively, had bleeding from portal hypertensive gastropathy (Log Rank Test, P =.20). Thirty and 25 patients, respectively, died during follow-up (Log Rank Test, P =.13). Twelve and 10 patients, respectively, had de novo occurrence of ascites during follow-up (Log Rank Test, P =.29). In conclusion, nadolol plus isosorbide mononitrate is significantly more effective than nadolol alone in the long-term use. Side effects are few, and no deleterious effects on ascites occurrence or on survival occur after long-term use of this combination.

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