SynthesisBMJ open2015
Exploring redundant research into the effect of tranexamic acid on surgical bleeding: further analysis of a systematic review of randomised controlled trials.
Synthesis in BMJ open, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
6 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Pooled it
- Several methods for assessing research waste in reviews with a systematic search: a scoping review.PeerJ · 2024Article
- Trends of Randomized Clinical Trials Citing Prior Systematic Reviews, 2007-2021.JAMA network open · 2023Article
- Meta-research evaluating redundancy and use of systematic reviews when planning new studies in health research: a scoping review.Systematic reviews · 2022Article
- Redundant trials can be prevented, if the EU clinical trial regulation is applied duly.BMC medical ethics · 2020Article
- Red blood cell transfusion in liver resection.Langenbeck's archives of surgery · 2019Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
Abstract
objectivesWe examined whether apparent redundancy in a cumulative meta-analysis of trials is justified by concern about bias, random error or generalisability of the results.
designCumulative meta-analysis, risk of bias assessment, trial sequential analysis, description of study participants over time and a review of rationales for conducting trials. DATA SOURCE: 126 randomised trials included in a systematic review assessing of tranexamic acid on blood transfusion in surgery.
resultsThe cumulative meta-analysis including all trials shows that the pooled estimate first reached statistical significance after the second trial in 1993. When the analysis was limited to the 38 high-quality trials and adjusted to account for potential systematic and random errors, the uncertainty was resolved after the 22nd trial in 2008. When the analysis was restricted to the two high-quality, prospectively registered trials, the cumulative z-curve crossed p=0.05 but not the monitoring boundary, suggesting an early potentially spurious statistically significant result. As precision of the pooled estimate increased, the number of trials initiated increased, although trial activity appeared to move to other surgery types. Most (62%) reports cited at least one systematic review. Of 118 reports examined, concern about generalisability was the reason for initiating the trial in 60%. Other reasons were to address a question other than the effect on bleeding (26%) and to confirm previously observed results (4%). Unawareness of previous research was apparent in 4% trials, while the rationale was unclear in 3%.
conclusionsOur results indicate that poor quality is a more important cause of redundant research than the failure to review existing evidence. Concerns about generalisability of results is the main motivation for new trials. Contrary to previous claims, our results suggest that systematic reviews showing treatment effects can stimulate an increase in trial activity rather than reduce it.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.