ArticleStatistics in medicine2019
Identifying inconsistency in network meta-analysis: Is the net heat plot a reliable method?
Article in Statistics in medicine, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 24 papers, 13 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
24 citing papers in PubMed, 13 syntheses or guidelines pooled it.
- Analysis of the efficacy and safety of liraglutide, semaglutide, and tirzepatide for the treatment of overweight and obesity: a systematic review and network meta-analysis.Journal of endocrinological investigation · 2026Pooled it
- Comparative efficacy of different exercise interventions for cancer-related fatigue, health-related quality of life, anxiety and depression symptoms in cancer survivors: a systematic review and network meta-analysis.BMC public health · 2026Pooled it
- Monitoring Liver and Spleen Stiffness Changes May Predict Clinical Response to Non-selective B-Blockers in Portal Hypertension: A Systematic Review and Meta-Analysis.Digestive diseases and sciences · 2026Pooled it
- Comparative effects of different exercise modalities on executive function in children with attention-deficit/hyperactivity disorder: a systematic review and network meta-analysis.Frontiers in psychology · 2026Pooled it
- Ticagrelor Paradox: Systematic Review and Network Meta-Analysis.Journal of the American Heart Association · 2025Pooled it
- Pooled it
- Comparative efficacy and safety of multimodality treatment for advanced hepatocellular carcinoma with portal vein tumor thrombus: patient-level network meta-analysis.Frontiers in oncology · 2024Pooled it
- Systematic review and network meta-analysis of the accuracy of the orthodontic mini-implants placed in the inter-radicular space by image-guided-based techniques.BMC oral health · 2023Pooled it
- Which type of mind-body exercise is most effective in improving functional performance and quality of life in patients with Parkinson's disease? A systematic review with network meta-analysis.Acta neurologica Belgica · 2022Pooled it
- Comparative safety of high-efficacy disease-modifying therapies in relapsing-remitting multiple sclerosis: a systematic review and network meta-analysis.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2022Pooled it
- Efficacy of regional anesthesia techniques for postoperative analgesia in patients undergoing major oncologic breast surgeries: a systematic review and network meta-analysis of randomized controlled trials.Canadian journal of anaesthesia = Journal canadien d'anesthesie · 2022Pooled it
- Pooled it
- Effect of exercise intervention dosage on reducing visceral adipose tissue: a systematic review and network meta-analysis of randomized controlled trials.International journal of obesity (2005) · 2021Pooled it
- Cold water immersion protocol optimization across exercise modalities: a systematic review and network meta-analysis of resistance training, endurance exercise, and team sport applications.BMC sports science, medicine & rehabilitation · 2026Article
- Methodologies for network meta-analysis of randomised controlled trials in pain, anaesthesia, and perioperative medicine: a narrative review.British journal of anaesthesia · 2025Review
- Network Meta-Analysis With Individual Participant-Level Data of Time-to-Event Outcomes Using Cox Regression.Statistics in medicine · 2025Article
- Comparison of Effectiveness Among Different Sodium-Glucose Cotransoporter-2 Inhibitors According to Underlying Conditions: A Network Meta-Analysis of Randomized Controlled Trials.Journal of the American Heart Association · 2024Article
- Comparative safety of tyrosine kinase inhibitors in the treatment of metastatic renal cell carcinoma: a systematic review and network meta-analysis.Frontiers in pharmacology · 2023Review
- Article
- Review
Corrections and comments
- Commented on by
- Erratum issued
Authors and funding
5 authors.
Funding
Abstract
One of the biggest challenges for network meta-analysis is inconsistency, which occurs when the direct and indirect evidence conflict. Inconsistency causes problems for the estimation and interpretation of treatment effects and treatment contrasts. Krahn and colleagues proposed the net heat approach as a graphical tool for identifying and locating inconsistency within a network of randomized controlled trials. For networks with a treatment loop, the net heat plot displays statistics calculated by temporarily removing each design one at a time, in turn, and assessing the contribution of each remaining design to the inconsistency. The net heat plot takes the form of a matrix which is displayed graphically with coloring indicating the degree of inconsistency in the network. Applied to a network of individual participant data assessing overall survival in 7531 patients with lung cancer, we were surprised to find no evidence of important inconsistency from the net heat approach; this contradicted other approaches for assessing inconsistency such as the Bucher approach, Cochran's Q statistic, node-splitting, and the inconsistency parameter approach, which all suggested evidence of inconsistency within the network at the 5% level. Further theoretical work shows that the calculations underlying the net heat plot constitute an arbitrary weighting of the direct and indirect evidence which may be misleading. We illustrate this further using a simulation study and a network meta-analysis of 10 treatments for diabetes. We conclude that the net heat plot does not reliably signal inconsistency or identify designs that cause inconsistency.
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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.