SynthesisDiabetes, obesity & metabolism2019
Glucose-lowering medications and the risk of cancer: A methodological review of studies based on real-world data.
Synthesis in Diabetes, obesity & metabolism, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 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
13 citing papers in PubMed, 1 synthesis or guideline pooled it.
- How well can we assess the validity of non-randomised studies of medications? A systematic review of assessment tools.BMJ open · 2021Pooled it
- Primary care physician documentation in oncology electronic health records: prognostic marker or immortal-time bias?ESMO real world data and digital oncology · 2026Article
- Emerging uncertainty on the anti-aging potential of metformin.Ageing research reviews · 2025Review
- Comparative estimation of the effects of antihypertensive medications on schizophrenia occurrence: a multinational observational cohort study.BMC psychiatry · 2024Observational
- Characteristics of non-randomised studies of drug treatments: cross sectional study.BMJ medicine · 2024Article
- Predictors of frequent emergency department visits among hospitalized cancer patients: a comparative cohort study using integrated clinical and administrative data to improve care delivery.BMC health services research · 2023Article
- Reproducibility of real-world evidence studies using clinical practice data to inform regulatory and coverage decisions.Nature communications · 2022Article
- Prevalence of Avoidable and Bias-Inflicting Methodological Pitfalls in Real-World Studies of Medication Safety and Effectiveness.Clinical pharmacology and therapeutics · 2022Article
- Conducting Real-world Evidence Studies on the Clinical Outcomes of Diabetes Treatments.Endocrine reviews · 2021Article
- Core Concept: The pandemic is prompting widespread use-and misuse-of real-world data.Proceedings of the National Academy of Sciences of the United States of America · 2020Article
- DPP4i, thiazolidinediones, or insulin and risks of cancer in patients with type 2 diabetes mellitus on metformin-sulfonylurea dual therapy with inadequate control.BMJ open diabetes research & care · 2020Article
- Transparency in real-world evidence (RWE) studies to build confidence for decision-making: Reporting RWE research in diabetes.Diabetes, obesity & metabolism · 2020Review
- Using RWE research to extend clinical trials in diabetes: An example with implications for the future.Diabetes, obesity & metabolism · 2020Review
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
Abstract
aimTo review the methodology of observational studies examining the association between glucose-lowering medications and cancer to identify the most common methodological challenges and sources of bias.
methodsWe searched PubMed systematically to identify observational studies on glucose-lowering medications and cancer published between January 2000 and January 2016. We assessed the design and analytical methods used in each study, with a focus on their ability to achieve study validity, and further evaluated the prevalence of major methodological choices over time.
resultsOf 155 studies evaluated, only 26% implemented a new-user design, 41% used an active comparator, 33% implemented a lag or latency period, and 51% adjusted for diabetes duration. Potential for immortal person-time bias was identified in 63% of the studies; 55% of the studies adjusted for variables measured during the follow-up without appropriate statistical methods. Aside from a decreasing trend in adjusting for variables measured during the follow-up, we observed no trends in methodological choices over time.
conclusionsThe prevalence of well-known design and analysis flaws that may lead to biased results remains high among observational studies on glucose-lowering medications and cancer, limiting the conclusions that can be drawn from these studies. Avoiding known pitfalls could substantially improve the quality and validity of real-world evidence in this field.
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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.