Abstract Evidence-based health-care decision making requires comparisons of all relevant competing interventions. In the absence of randomized, controlled trials involving a direct comparison of all ...treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best choice(s) of treatment. Mixed treatment comparisons, a special case of network meta-analysis, combine direct and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than a traditional meta-analysis. This report from the ISPOR Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on the interpretation of indirect treatment comparisons and network meta-analysis to assist policymakers and health-care professionals in using its findings for decision making. We start with an overview of how networks of randomized, controlled trials allow multiple treatment comparisons of competing interventions. Next, an introduction to the synthesis of the available evidence with a focus on terminology, assumptions, validity, and statistical methods is provided, followed by advice on critically reviewing and interpreting an indirect treatment comparison or network meta-analysis to inform decision making. We finish with a discussion of what to do if there are no direct or indirect treatment comparisons of randomized, controlled trials possible and a health-care decision still needs to be made.
Abstract Despite the great realized or potential value of network meta-analysis of randomized controlled trial evidence to inform health care decision making, many decision makers might not be ...familiar with these techniques. The Task Force developed a consensus-based 26-item questionnaire to help decision makers assess the relevance and credibility of indirect treatment comparisons and network meta-analysis to help inform health care decision making. The relevance domain of the questionnaire (4 questions) calls for assessments about the applicability of network meta-analysis results to the setting of interest to the decision maker. The remaining 22 questions belong to an overall credibility domain and pertain to assessments about whether the network meta-analysis results provide a valid answer to the question they are designed to answer by examining 1) the used evidence base, 2) analysis methods, 3) reporting quality and transparency, 4) interpretation of findings, and 5) conflicts of interest. The questionnaire aims to help readers of network meta-analysis opine about their confidence in the credibility and applicability of the results of a network meta-analysis, and help make decision makers aware of the subtleties involved in the analysis of networks of randomized trial evidence. It is anticipated that user feedback will permit periodic evaluation and modification of the questionnaire.
Abstract Evidence-based health care decision making requires comparison of all relevant competing interventions. In the absence of randomized controlled trials involving a direct comparison of all ...treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best treatment(s). Mixed treatment comparisons, a special case of network meta-analysis, combine direct evidence and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than traditional meta-analysis. This report from the International Society for Pharmacoeconomics and Outcomes Research Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on technical aspects of conducting network meta-analyses (our use of this term includes most methods that involve meta-analysis in the context of a network of evidence). We start with a discussion of strategies for developing networks of evidence. Next we briefly review assumptions of network meta-analysis. Then we focus on the statistical analysis of the data: objectives, models (fixed-effects and random-effects), frequentist versus Bayesian approaches, and model validation. A checklist highlights key components of network meta-analysis, and substantial examples illustrate indirect treatment comparisons (both frequentist and Bayesian approaches) and network meta-analysis. A further section discusses eight key areas for future research.
Abstract Recently, mixed treatment comparisons (MTC) have been presented as an extension of traditional meta-analysis by including multiple different pairwise comparisons across a range of different ...interventions. MTC allow for indirect comparisons and can therefore provide very useful information for clinical and reimbursement decision-making in the absence of head-to-head data. In this article, we provide an introductory overview of MTC illustrated with example analyses of different drug treatments in rheumatoid arthritis using a continuous patient-reported end point. As a background, we start with an overview of the traditional meta-analyses for pairwise trials, and the difference between a traditional approach and a Bayesian approach. Next, the Bayesian MTC for continuous outcomes are presented. We finish with a discussion of how MTC can best be presented in order to maximize acceptance by target audiences, i.e., clinicians and market access decision-makers.
Abstract Context With many medications available for the management of breakthrough cancer pain (BTCP), physicians may require additional guidance in selecting an appropriate medication to suit an ...individual patient's needs. Objectives To identify all the evidence and assess the relative clinical value of currently approved BTCP medications. Methods Following a systematic literature search (2007–2010), the results of 10 randomized controlled trials investigating the effects of BTCP medications (intranasal fentanyl spray INFS, fentanyl pectin nasal spray, fentanyl sublingual tablets, fentanyl buccal soluble film, fentanyl buccal tablets, oral transmucosal fentanyl citrate, and morphine sulfate immediate release) were synthesized using a network meta-analysis. The main outcome was pain intensity difference (PID) relative to placebo up to 60 minutes after the intake of medication. Results INFS, fentanyl pectin nasal spray, fentanyl buccal tablet, and oral transmucosal fentanyl citrate showed greater PIDs relative to placebo than other BTCP medications 15 minutes after intake. All other medications showed greater PIDs relative to placebo at 30 minutes, except morphine sulfate immediate release, which did not show efficacy over placebo until 45 minutes. Only INFS produced clinically meaningful pain relief (absolute PID ≥2) at 15 minutes. Conclusion From current evidence, although all BTCP medications provided pain relief within the time frames assessed, transmucosal fentanyl medications achieved a greater level of pain relief in a shorter time frame than placebo or oral morphine.
Abstract Purpose Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). This analysis compared the efficacy and safety of tofacitinib with biologic ...disease-modifying antirheumatic drugs in patients with RA and a prior inadequate response (IR) to tumor necrosis factor inhibitors (TNFi). Methods A systematic literature review identified 5 randomized placebo-controlled trials that evaluated tofacitinib or biologic disease-modifying antirheumatic drugs (bDMARDs) against placebo in patient populations with RA with a prior IR to TNFi. The definition of TNFi-IR varied across studies, and included patients with an IR or who had failed treatment with TNFi for any reason. A network meta-analysis was conducted comparing study data with regard to American College of Rheumatology response rates and Health Assessment Questionnaire-Disability Index improvement at weeks 12 and 24, rates of treatment withdrawal due to all causes; adverse events (AEs) and lack of efficacy; and rates of AEs, serious AEs, and serious infections. Findings The 5 trials included a total of 2136 patients. Tofacitinib 5 mg twice daily combined with methotrexate was found to have relative risk estimates of American College of Rheumatology responses and change from baseline in Health Assessment Questionnaire-Disability Index score comparable with abatacept, golimumab, rituximab, and tocilizumab combined with conventional synthetic disease-modifying antirheumatic drugs. Withdrawal rates from trials due to all causes and AEs were comparable between treatments, and tofacitinib had a lower rate of withdrawals due to lack of efficacy. Rates of AEs and HAQ-DI were comparable between tofacitinib, other active treatments, and placebo. No serious infections were reported with tofacitinib during the placebo-controlled period (up to week 12) in this study population; rates of serious infection with other active treatments were generally low and similar to placebo. Implications During a 24-week period, tofacitinib had efficacy and rates of AEs comparable with currently available bDMARDs in the treatment of patients with RA who had a prior IR to TNFi. ClinicalTrials.gov identifiers: ORAL Step, NCT00960440; ATTAIN, NCT00124982; GO-AFTER, NCT00299546; RADIATE, NCT00106522; REFLEX, NCT00462345.
Objective To evaluate the efficacy of available bisphosphonate therapies regarding the prevention of vertebral, hip, and nonvertebral-nonhip fractures in postmenopausal women with osteoporosis. ...Methods Eight randomized placebo controlled trials investigating the effects of zoledronic acid (1 study), alendronate (3), ibandronate (1), risedronate (2), and etidronate (1) in terms of fractures with a follow-up of 3 years (or 2 years if used for registration purposes) were identified with a systematic literature search. The endpoints of interest were morphometric vertebral fractures, hip fractures, and nonvertebral-nonhip fractures. Results of all trials were analyzed simultaneously with a Bayesian network meta-analysis by which the relative treatment effect of 1 intervention to another can be obtained in the absence of head-to-head evidence. Given the estimated treatment effects and their uncertainty, the Bayesian approach allowed for calculations of the probability of which bisphosphonate is best in terms of overall fracture reductions by weighting the impact of each by type of fracture on costs, quality of life, and incidence. Results There is a 79% probability that zoledronic acid shows the greatest reduction in vertebral fractures of all bisphophonates compared. Zoledronic acid showed a relative risk (RR) of 0.30 (95% Credible Interval 0.23-0.37) relative to placebo, an RR of 0.55 (0.41-0.76) relative to alendronate, an RR of 0.50 (0.36-0.70) relative to risedronate, and an RR of 0.58 (0.37-0.92) relative to ibandronate. Regarding hip fractures, there is a 47% probability that zoledronic acid shows the greatest risk reduction, followed by alendronate (36%) and risedronate (11%). RRs of zoledronic acid relative to placebo, alendronate, and risedronate were 0.58 (0.41-0.82), 0.95 (0.54-1.68), and 0.73 (0.37-1.44), respectively. Risedronate showed the greatest reduction in nonvertebral-nonhip fractures, followed by zoledronic acid. The RR of zoledronic acid relative to risedronate was 1.28 (0.87-1.90). Overall, there was a 94% probability that zoledronic acid showed the greatest reduction in any fracture. Weighting the impact of the different type of fractures by incidence, cost, or quality of life showed similar results. Conclusion Of the available bisphosphonates for osteoporosis, zoledronic acid has the highest probability of offering the best overall fracture protection.
Objectives To compare the patterns of American College of Rheumatology (ACR) response between tocilizumab and other biologic agents in patients with rheumatoid arthritis who have inadequate response ...to disease-modifying antirheumatic drugs (DMARD-IR). Methods Systematic literature review identified similarly designed double-blind, randomized, placebo-controlled trials over an 18-year period that investigated the effectiveness of abatacept (2), rituximab (2), and TNF-α inhibitors etanercept, infliximab, and adalimumab (11) in DMARD-IR patients; data from 3 placebo-controlled, phase 3 trials for tocilizumab, a newly developed IL-6 inhibitor, were included. The endpoint of interest was ACR20/50/70 response criteria at 24 to 30 weeks. Results were analyzed simultaneously using Bayesian mixed-treatment comparison techniques. Nonoverlapping ACR response rates (<ACR20, ACR20-50, ACR50-70, >ACR70) for each agent were compared among treatments to identify differences in ACR response pattern. Separate analyses of overlapping ACR20/50/70 responses were conducted to identify the source of any differences. Results were expressed as relative risk of ACR20/50/70 response and associated 95% credible interval (CrI). Results Patterns across nonoverlapping ACR response levels varied significantly across treatments. In subsequent analyses, the effectiveness of tocilizumab appeared to be comparable to that of other biologic agents for ACR20 and ACR50 responses but greater for ACR70. Specifically, tocilizumab had greater ACR70 responses than both TNF-α inhibitors (relative risk = 1.8; CrI = 1.2, 2.6) and abatacept (relative risk = 2.0; CrI = 1.3, 3.1). Conclusions Among DMARD-IR patients, tocilizumab shows a pattern of response that differs from that of other biologic agents. Post-hoc analyses suggest that the difference lies in a higher likelihood of ACR70 response with tocilizumab.
Abstract Objective To compare the efficacy of bazedoxifene and oral bisphosphonates for the prevention of nonvertebral fractures (NVFs) in women with higher risk of postmenopausal osteoporosis (i.e., ...the Fracture Risk Assessment Tool FRAX score ≥ 20%), based on currently available evidence from randomized controlled trials. Methods Randomized controlled trials evaluating the NVF relative risk reduction (RRR) with oral bisphosphonates or bazedoxifene were identified by a systematic literature review and combined by means of a network meta-analysis. A subgroup of patients with a FRAX score of 20% or more in the bazedoxifene phase III osteoporosis study was selected as the population of interest on the basis of the bazedoxifene label. In one analysis (analysis 1), the placebo response of the subgroup with a FRAX score of 20% or more was the benchmark to select comparable bisphosphonate trials. Additional analyses incorporated the aggregate data from the bisphosphonate trials with all the FRAX subgroups (analysis 2) or with the individual patient data from the bazedoxifene trial (analysis 3). Results Nine identified bisphosphonate trials (alendronate, ibandronate, risedronate; N = 23,440 patients) with a similar placebo response as observed for the subgroup of high risk patients in the bazedoxifene trial were included in analysis 1. The results of the network meta-analysis of this study set suggest that bazedoxifene is expected to have an RRR of 0.43 (95% credible interval CrI −0.19 to 0.72) versus alendronate, 0.58 (95% CrI 0.05–0.81) versus ibandronate, and 0.39 (95% CrI −0.29 to 0.70) versus risedronate. Analyses in which treatment effects with bisphosphonates were projected to a population with a FRAX score of 20% or more with meta-regression approaches (analysis 2 and analysis 3) provide similar findings. Conclusion Based on an indirect comparison of randomized trials, bazedoxifene is expected to have at least a comparable RRR of NVF as alendronate, ibandronate, and risedronate in women with higher risk of postmenopausal osteoporosis.
Abstract Objectives To critically appraise published network meta-analyses (NMAs) evaluating the efficacy or safety of the new oral anticogulants (NOACs) dabigatran, rivaroxaban, and apixaban for the ...prevention of stroke in patients with nonvalvular atrial fibrillation (AF). Methods A systematic literature review was performed to identify the relevant NMAs using MEDLINE, EMBASE, Cochrane Library, Database of Abstracts of Reviews of Effects, and Health Technology Assessment. The synthesis studies were evaluated using the “Questionnaire to assess the relevance and credibility of the NMA.” Results Eleven NMAs evaluating NOACs among adults with nonvalvular AF were identified. Most NMAs included three large phase III randomized controlled trials, comparing NOACs to adjusted-dose warfarin (Randomized Evaluation of Long-Term Anticoagulation Therapy RE-LY, Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation ROCKET-AF, and Apixaban for Reduction of Stroke and Other Thromboembolic Events in Atrial Fibrillation ARISTOTLE). The main differences identified related to potential treatment effect modifiers regarding the mean time spent in therapeutic range (TTR) in the warfarin arm, the risk of stroke or systemic embolism across the trials (mean CHADS2 score: C = congestive heart failure, H = hypertension, A = older than age 75 years, D = diabetes mellitus, S2 = prior stroke or history of transient ischemic attack) or primary versus secondary prevention, and type of populations used in the analysis. Kansal et al. Kansal AR, Sharma M, Bradley-Kennedy C, et al. Dabigatran versus rivaroxaban for the prevention of stroke and systemic embolism in atrial fibrillation in Canada: comparative efficacy and cost-effectiveness. Thromb Haemost 2012;108:672–82 appropriately adjusted the ROCKET-AF TTR to match the RE-LY population on the basis of individual patient data. Meta-regressions are not expected to minimize confounding bias given limited data, whereas subgroup analyses had some impact on the point estimates for the treatment comparisons. Conclusions Results of the synthesis studies were generally comparable and suggested that the NOACs had similar efficacy, although some differences were identified depending on the outcome. The extent to which differences in the distribution of TTR, CHADS2 score, or primary versus secondary prevention biased the results remains unclear.
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