339 research outputs found

    Deterministic and Probabilistic Analysis of a Simple Markov Model: How Different Could They Be?

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    Network Meta-analysis on Disconnected Evidence Networks When Only Aggregate Data Are Available:Modified Methods to Include Disconnected Trials and Single-Arm Studies while Minimizing Bias

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    BACKGROUND: Network meta-analysis (NMA) requires a connected network of randomized controlled trials (RCTs) and cannot include single-arm studies. Regulators or academics often have only aggregate data. Two aggregate data methods for analyzing disconnected networks are random effects on baseline and aggregate-level matching (ALM). ALM has been used only for single-arm studies, and both methods may bias effect estimates. METHODS: We modified random effects on baseline to separate RCTs connected to and disconnected from the reference and any single-arm studies, minimizing the introduction of bias. We term our modified method reference prediction. We similarly modified ALM and extended it to include RCTs disconnected from the reference. We tested these methods using constructed data and a simulation study. RESULTS: In simulations, bias for connected treatments for ALM ranged from −0.0158 to 0.051 and for reference prediction from −0.0107 to 0.083. These were low compared with the true mean effect of 0.5. Coverage ranged from 0.92 to 1.00. In disconnected treatments, bias of ALM ranged from −0.16 to 0.392 and of reference prediction from −0.102 to 0.40, whereas coverage of ALM ranged from 0.30 to 0.82 and of reference prediction from 0.64 to 0.94. Under fixed study effects for disconnected evidence, bias was similar, but coverage was 0.81 to 1.00 for reference prediction and 0.18 to 0.76 for ALM. Trends of similar bias but greater coverage for reference prediction with random study effects were repeated in constructed data. CONCLUSIONS: Both methods with random study effects seem to minimize bias in treatment connected to the reference. They can estimate treatment effects for disconnected treatments but may be biased. Reference prediction has greater coverage and may be recommended overall. HIGHLIGHTS: Two methods were modified for network meta-analysis on disconnected networks and for including single-arm observational or interventional studies in network meta-analysis using only aggregate data and for minimizing the bias of effect estimates for treatments only in trials connected to the reference. Reference prediction was developed as a modification of random effects on baseline that keeps analyses of trials connected to the reference separately from those disconnected from the reference and from single-arm studies. The method was further modified to account for correlation in trials with more than 2 arms and, under random study effects, to estimate variance in heterogeneity separately in connected and disconnected evidence. Aggregate-level matching was extended to include trials disconnected from the reference, rather than only single-arm studies. The method was further modified to separately estimate treatment effects and heterogeneity variance in the connected and disconnected evidence and to account for the correlation between arms in trials with more than 2 arms. Performance was assessed using a constructed data example and simulation study. The methods were found to have similar, and sometimes low, bias when estimating the relative effects for disconnected treatments, but reference prediction with random study effects had the greatest coverage. The use of reference prediction with random study effects for disconnected networks is recommended if no individual patient data or alternative real-world evidence is available

    Crisaborole Ointment, 2%, for Treatment of Patients with Mild-to-Moderate Atopic Dermatitis:Systematic Literature Review and Network Meta-Analysis

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    The authors would like to replace 2 small sections of the published manuscript that refer to a qualitative review of safety data for included studies (together with an associated safety table), to provide some further clarifications on these safety data and to include some quantitative updates for rates

    Matching-Adjusted Indirect Comparison of Crisaborole Ointment 2% vs. Topical Calcineurin Inhibitors in the Treatment of Patients with Mild-to-Moderate Atopic Dermatitis

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    INTRODUCTION: Crisaborole topical ointment, 2%, is a nonsteroidal, topical anti-inflammatory phosphodiesterase-4 (PDE4) inhibitor that is approved for the treatment of mild-to-moderate atopic dermatitis (AD). The objective of the current analysis was to compare the efficacy of crisaborole 2% relative to pimecrolimus 1%, tacrolimus 0.03% and tacrolimus 0.1% in patients aged ≥ 2 years with mild-to-moderate AD by comparing improvement in Investigator’s Static Global Assessment scores ( (ISGA scores of 0/1 indicating “clear or almost clear”). ISGA was selected as the primary efficacy outcome given the US Food and Drug Administration’s recommendations on the use of ISGA for assessment of global severity in AD and to align with efficacy measurements in the crisaborole registration trials. Safety endpoints could not be analyzed due to differences in outcome definitions across studies. METHODS: Efficacy of crisaborole was evaluated using individual patient data (IPD) from two pivotal phase III randomized controlled trials (RCTs), and efficacy of comparators was evaluated using published RCTs included in a previous network meta-analysis. Vehicle controls were not comparable due to differences in ingredients and population imbalance and, therefore, an unanchored matching-adjusted indirect comparison (MAIC) was used, which reweighted IPD for crisaborole to estimate absolute response in comparator populations. RESULTS: The odds of achieving an improvement in ISGA score was higher with crisaborole 2% versus pimecrolimus 1% (odds ratio [OR] 2.03; 95% confidence interval [CI] 1.45–2.85; effective sample size =  627, reduced from 1021; p value < 0.001) and for crisaborole 2% versus tacrolimus 0.03% (OR 1.50; 95% CI 1.09–2.05; effective sample size = 311, reduced from 1021; p = 0.012). CONCLUSION: The unanchored MAIC suggests that the odds of achieving an improvement in ISGA score is greater with crisaborole 2% than with pimecrolimus 1% or tacrolimus 0.03% in patients aged ≥ 2 years with mild-to-moderate AD. These results are consistent with findings from the previously published network meta-analysis, which used a different methodology for performing indirect treatment comparisons. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13555-021-00646-1

    Accuracy of potential diagnostic indicators for coeliac disease:a systematic review protocol

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    INTRODUCTION: Coeliac disease (CD) is a systemic immune-mediated disorder triggered by gluten in genetically predisposed individuals. CD is diagnosed using a combination of serology tests and endoscopic biopsy of the small intestine. However, because of non-specific symptoms and heterogeneous clinical presentation, diagnosing CD is challenging. Early detection of CD through improved case-finding strategies can improve the response to a gluten-free diet, patients' quality of life and potentially reduce the risk of complications. However, there is a lack of consensus in which groups may benefit from active case-finding. METHODS AND ANALYSIS: We will perform a systematic review to determine the accuracy of diagnostic indicators (such as symptoms and risk factors) for CD in adults and children, and thus can help identify patients who should be offered CD testing. MEDLINE, Embase, Cochrane Library and Web of Science will be searched from 1997 until 2020. Screening will be performed in duplicate. Data extraction will be performed by one and checked by a second reviewer. Disagreements will be resolved through discussion or referral to a third reviewer. We will produce a narrative summary of identified prediction models. Studies, where 2×2 data can be extracted or reconstructed, will be treated as diagnostic accuracy studies, that is, the diagnostic indicators are the index tests and CD serology and/or biopsy is the reference standard. For each diagnostic indicator, we will perform a bivariate random-effects meta-analysis of the sensitivity and specificity. ETHICS AND DISSEMINATION: Results will be reported in peer-reviewed journals, academic and public presentations and social media. We will convene an implementation panel to advise on the optimum strategy for enhanced dissemination. We will discuss findings with Coeliac UK to help with dissemination to patients. Ethical approval is not applicable, as this is a systematic review and no research participants will be involved. PROSPERO REGISTRATION NUMBER: CRD42020170766

    Oral anticoagulants for prevention of stroke in atrial fibrillation : systematic review, network meta-analysis, and cost effectiveness analysis

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    Objective To compare the efficacy, safety, and cost effectiveness of direct acting oral anticoagulants (DOACs) for patients with atrial fibrillation.Design Systematic review, network meta-analysis, and cost effectiveness analysis. Data sources Medline, PreMedline, Embase, and The Cochrane Library.Eligibility criteria for selecting studies Published randomised trials evaluating the use of a DOAC, vitamin K antagonist, or antiplatelet drug for prevention of stroke in patients with atrial fibrillation.Results 23 randomised trials involving 94 656 patients were analysed: 13 compared a DOAC with warfarin dosed to achieve a target INR of 2.0-3.0. Apixaban 5 mg twice daily (odds ratio 0.79, 95% confidence interval 0.66 to 0.94), dabigatran 150 mg twice daily (0.65, 0.52 to 0.81), edoxaban 60 mg once daily (0.86, 0.74 to 1.01), and rivaroxaban 20 mg once daily (0.88, 0.74 to 1.03) reduced the risk of stroke or systemic embolism compared with warfarin. The risk of stroke or systemic embolism was higher with edoxaban 60 mg once daily (1.33, 1.02 to 1.75) and rivaroxaban 20 mg once daily (1.35, 1.03 to 1.78) than with dabigatran 150 mg twice daily. The risk of all-cause mortality was lower with all DOACs than with warfarin. Apixaban 5 mg twice daily (0.71, 0.61 to 0.81), dabigatran 110 mg twice daily (0.80, 0.69 to 0.93), edoxaban 30 mg once daily (0.46, 0.40 to 0.54), and edoxaban 60 mg once daily (0.78, 0.69 to 0.90) reduced the risk of major bleeding compared with warfarin. The risk of major bleeding was higher with dabigatran 150 mg twice daily than apixaban 5 mg twice daily (1.33, 1.09 to 1.62), rivaroxaban 20 mg twice daily than apixaban 5 mg twice daily (1.45, 1.19 to 1.78), and rivaroxaban 20 mg twice daily than edoxaban 60 mg once daily (1.31, 1.07 to 1.59). The risk of intracranial bleeding was substantially lower for most DOACs compared with warfarin, whereas the risk of gastrointestinal bleeding was higher with some DOACs than warfarin. Apixaban 5 mg twice daily was ranked the highest for most outcomes, and was cost effective compared with warfarin.Conclusions The network meta-analysis informs the choice of DOACs for prevention of stroke in patients with atrial fibrillation. Several DOACs are of net benefit compared with warfarin. A trial directly comparing DOACs would overcome the need for indirect comparisons to be made through network meta-analysis
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