SynthesisCanadian journal of surgery. Journal canadien de chirurgie2012
Meta-analytic comparison of randomized and nonrandomized studies of breast cancer surgery.
Synthesis in Canadian journal of surgery. Journal canadien de chirurgie, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 4 of them syntheses 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
8 citing papers in PubMed, 4 syntheses or guidelines pooled it.
- Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials: a meta-epidemiological study.The Cochrane database of systematic reviews · 2024Pooled it
- Discontinuation of non-anti-TNF drugs for rheumatoid arthritis in interventional versus observational studies: a systematic review and meta-analysis.European journal of clinical pharmacology · 2018Pooled it
- Healthcare outcomes assessed with observational study designs compared with those assessed in randomized trials.The Cochrane database of systematic reviews · 2014Pooled it
- Using multiple types of studies in systematic reviews of health care interventions--a systematic review.PloS one · 2013Pooled it
- An empirical comparison of the harmful effects for randomized controlled trials and non-randomized studies of interventions.Frontiers in pharmacology · 2023Article
- Rational for meta-analysis and randomized treatment: the COVID-19 example.Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases · 2021Article
- Is there an efficacy-effectiveness gap between randomized controlled trials and real-world studies in colorectal cancer: a systematic review and meta-analysis.Translational cancer research · 2020Article
- Effect Estimates in Randomized Trials and Observational Studies: Comparing Apples With Apples.American journal of epidemiology · 2019Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundRandomized controlled trials (RCTs) are thought to provide the most accurate estimation of "true" treatment effect. The relative quality of effect estimates derived from nonrandomized studies (nRCTs) remains unclear, particularly in surgery, where the obstacles to performing high-quality RCTs are compounded. We performed a meta-analysis of effect estimates of RCTs comparing surgical procedures for breast cancer relative to those of corresponding nRCTs.
methodsEnglish-language RCTs of breast cancer treatment in human patients published from 2003 to 2008 were identified in MEDLINE, EMBASE and Cochrane databases. We identified nRCTs using the National Library of Medicine's "related articles" function and reference lists. Two reviewers conducted all steps of study selection. We included studies comparing 2 surgical arms for the treatment of breast cancer. Information on treatment efficacy estimates, expressed as relative risk (RR) for outcomes of interest in both the RCTs and nRCTs was extracted.
resultsWe identified 12 RCTs representing 10 topic/outcome combinations with comparable nRCTs. On visual inspection, 4 of 10 outcomes showed substantial differences in summary RR. The pooled RR estimates for RCTs versus nRCTs differed more than 2-fold in 2 of 10 outcomes and failed to demonstrate consistency of statistical differences in 3 of 10 cases. A statistically significant difference, as assessed by the z score, was not detected for any of the outcomes.
conclusionRandomized controlled trials comparing surgical procedures for breast cancer may demonstrate clinically relevant differences in effect estimates in 20%-40% of cases relative to those generated by nRCTs, depending on which metric is used.
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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.