1.
Tranexamic acid for upper gastrointestinal bleeding
Bennett C, Klingenberg SL, Langholz E, Gluud LL
Cochrane Database of Systematic Reviews. 2014;11:CD006640.
Abstract
Background Tranexamic acid reduces haemorrhage through its antifibrinolytic effects. In a previous version of the present review, we found that tranexamic acid may reduce mortality. This review includes updated searches and new trials.Objectives To assess the effects of tranexamic acid versus no intervention, placebo or other antiulcer drugs for upper gastrointestinal bleeding.Search methods We updated the review by performing electronic database searches (Cochrane Central Register of Controlled Trials (CENTRAL),MEDLINE, EMBASE, Science Citation Index) and manual searches in July 2014.Selection criteriaRandomised controlled trials, irrespective of language or publication status.Data collection and analysis We used the standard methodological procedures of the The Cochrane Collaboration. All-cause mortality, bleeding and adverse events were the primary outcome measures. We performed fixed-effect and random-effects model meta-analyses and presented results as risk ratios (RRs) with 95% confidence intervals (CIs) and used I2 as a measure of between-trial heterogeneity. We analysed tranexamic acid versus placebo or no intervention and tranexamic acid versus antiulcer drugs separately. To analyse sources of heterogeneity and robustness of the overall results, we performed subgroup, sensitivity and sequential analyses.Main results We included eight randomised controlled trials on tranexamic acid for upper gastrointestinal bleeding. Additionally, we identified one large ongoing pragmatic randomised controlled trial from which data are not yet available. Control groups were randomly assigned to placebo (seven trials) or no intervention (one trial). Two trials also included a control group randomly assigned to antiulcer drugs(lansoprazole or cimetidine). The included studies were published from 1973 to 2011. The number of participants randomly assigned ranged from 47 to 216 (median 204). All trials reported mortality. In total, 42 of 851 participants randomly assigned to tranexamic acid and 71 of 850 in the control group died (RR 0.60, 95% CI 0.42 to 0.87; P value 0.007; I2 = 0%). The analysis was not confirmed when all participants in the intervention group with missing outcome data were included as treatment failures, or when the analysis was limited to trials with low risk of attrition bias. Rebleeding was diagnosed for 117 of 826 participants in the tranexamic acid group and for 146 of 825 participants in the control group (RR 0.80, 95% CI 0.64 to 1.00; P value 0.07; I2 = 49%).We were able to evaluate the risk of serious adverse events on the basis of only four trials. Our analyses showed 'no evidence of a difference between tranexamic acid and control interventions regarding the risk of thromboembolic events.' Tranexamic acid appeared to reduce the risk of surgery ina fixed-effect meta-analysis (RR 0.73, 95% CI 0.56 to 0.95), but this result was no longer statistically significant in a random-effects meta-analysis (RR 0.61, 95% CI 0.35 to 1.04; P value 0.07). No difference was apparent between tranexamic acid and placebo in the assessment of transfusion (RR 1.02, 95% CI 0.94 to 1.11; I2 = 0%), and meta-analyses that compared tranexamic acid versus antiulcer drugs did not identify beneficial or detrimental effects of tranexamic acid for any of the outcomes assessed.Authors' conclusions This review found that tranexamic acid appears to have a beneficial effect on mortality, but a high dropout rate in some trials means that we cannot be sure of this until the findings of additional research are published. At the time of this update in 2014, one large study(8000 participants) is in progress, so this review will be much more informative in a few years. Further examination of tranexamic acid would require inclusion of high-quality randomised controlled trials. Timing of randomisation is essential to avoid attrition bias and to limit the number of withdrawals. Future trials may use a pragmatic design and should include all participants with suspected bleeding or with endoscopically verified bleeding, as well as a tranexamic pla
2.
Recombinant human erythropoietin and overall survival in cancer patients: results of a comprehensive meta-analysis
Bohlius J, Langensiepen S, Schwarzer G, Seidenfeld J, Piper M, Bennett C, Engert A
Journal of the National Cancer Institute. 2005;97((7):):489-98.
3.
Epoetin treatment of anemia associated with cancer therapy: a systematic review and meta-analysis of controlled clinical trials
Seidenfeld J, Piper M, Flamm C, Hasselblad V, Armitage JO, Bennett C, Gordon MS, Lichtin AE, Wade JL Iii, Woolf S, et al
Journal of the National Cancer Institute. 2001;93((16):):1204-14.
Abstract
Epoetin treatment offers an attractive but costly alternative to red blood cell transfusion for managing anemia associated with cancer therapy. The goal of this review is to facilitate more efficient use of epoetin by 1) quantifying the effects of epoetin on the likelihood of transfusion and on quality of life in patients with cancer treatment-related anemia and 2) evaluating whether outcomes are superior when epoetin treatment is initiated at higher hemoglobin thresholds. Two independent reviewers followed a prospective protocol for identifying studies. Outcomes data were combined with the use of a random-effects meta-analysis model. Double-blind, randomized, controlled trials that minimized patient exclusions were defined as higher quality for sensitivity analysis; randomized but unblinded trials and trials with excessive exclusions were included in the metaanalysis but were defined as lower quality. Twenty-two trials (n = 1927) met inclusion criteria, and 12 (n = 1390) could be combined for estimation of odds of transfusion. Epoetin decreased the percentage of patients transfused by 9%-45% in adults with mean baseline hemoglobin concentrations of 10 g/dL or less (seven trials; n = 1080), by 7%-47% in those with hemoglobin concentrations greater than 10 g/dL but less than 12 g/dL (seven trials; n = 431), and by 7%-39% in those with hemoglobin concentrations of 12 g/dL or higher (five trials; n = 308). In sensitivity analysis, the combined odds ratio for transfusion in epoetin-treated patients as compared with controls was 0.45 (95% confidence interval (CI) = 0.33 to 0.62) in higher quality studies and 0.14 (95% CI = 0.06 to 0.31) in lower quality studies. The number of patients needed to treat to prevent one transfusion is 4.4 for all studies, 5.2 for higher quality studies, and 2.6 for lower quality studies. Only studies with mean baseline hemoglobin concentrations of 10 g/dL or less reported statistically significant effects of epoetin treatment on quality of life; quality-of-life data were insufficient for meta-analysis. No studies addressed epoetin's effects on anemiarelated symptoms. We conclude that epoetin reduces the odds of transfusion for cancer patients undergoing therapy. Evidence is insufficient to determine whether initiating epoetin earlier spares more patients from transfusion or results in better quality of life than waiting until hemoglobin concentrations decline to nearly 10 g/d L.