Evidence map›Paper›PMID 24475020›Full record

SynthesisPloS one2014

Do optimal prognostic thresholds in continuous physiological variables really exist? Analysis of origin of apparent thresholds, with systematic review for peak oxygen consumption, ejection fraction and BNP.

Alberto Giannoni, Resham Baruah, Tora Leong, Michaela B Rehman, Luigi Emilio Pastormerlo, Frank E Harrell, Andrew J S Coats, Darrel P Francis

Erratum issuedOpen access · goldAbstract readSystematic Review
In one paragraph

Synthesis in PloS one, 2014. 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, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
24citing papers in PubMed, 1 pooled it
2.0field-weighted citation impact, top 13% of its field
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

24 citing papers in PubMed, 1 synthesis or guideline pooled it, 48 citations in OpenAlex.

  1. How robust are recommended waiting times to pacing after cardiac surgery that are derived from observational data?Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology · 2023
    Pooled it
  2. Article
  3. Article
  4. Uncertainty undermines the validity of antimicrobial pharmacodynamics.Journal of pharmacokinetics and pharmacodynamics · 2026
    Article
  5. Article
  6. Review
  7. Article
  8. Article
  9. Brain responses vary in duration-modeling strategies and challenges.Imaging neuroscience (Cambridge, Mass.) · 2025
    Article
  10. Article
  11. Article
  12. Article
  13. Article
  14. How Much Blood Loss Is Too Much for a 1-Level Open Lumbar Fusion?International journal of spine surgery · 2023
    Article
  15. Article
  16. Article
  17. Article
  18. Article
  19. Article
  20. Article
4 · The record

Corrections and comments

  • Erratum issued
5 · Who and what money

Authors and funding

8 authors at 5 institutions in 4 countries.

Alberto GiannoniInternational Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, United Kingdom ; Department of Cardiovascular Medicine, Fondazione Toscana G. Monasterio, Pisa, Italy.
Resham BaruahInternational Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, United Kingdom.
Tora LeongInternational Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, United Kingdom.
Michaela B RehmanCardiology Department, Poitiers University Hospital, Poitiers, France.
Luigi Emilio PastormerloDepartment of Cardiovascular Medicine, Fondazione Toscana G. Monasterio, Pisa, Italy.
Frank E HarrellVanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
Andrew J S CoatsInternational Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, United Kingdom ; Norfolk and Norwich Hospital, University of East Anglia, Norwich, United Kingdom.
Darrel P FrancisInternational Centre for Circulatory Health, National Heart and Lung Institute, Imperial College, London, United Kingdom.
Imperial College London · GBFondazione Toscana Gabriele Monasterio · ITUniversité de Poitiers · FRUniversity of East Anglia · GBVanderbilt University · US

Funding

British Heart Foundation FS/10/38/28268
6 · The paper itself

Abstract

backgroundClinicians are sometimes advised to make decisions using thresholds in measured variables, derived from prognostic studies.

objectivesWe studied why there are conflicting apparently-optimal prognostic thresholds, for example in exercise peak oxygen uptake (pVO2), ejection fraction (EF), and Brain Natriuretic Peptide (BNP) in heart failure (HF). DATA SOURCES AND ELIGIBILITY CRITERIA: Studies testing pVO2, EF or BNP prognostic thresholds in heart failure, published between 1990 and 2010, listed on Pubmed.

methodsFirst, we examined studies testing pVO2, EF or BNP prognostic thresholds. Second, we created repeated simulations of 1500 patients to identify whether an apparently-optimal prognostic threshold indicates step change in risk.

results33 studies (8946 patients) tested a pVO2 threshold. 18 found it prognostically significant: the actual reported threshold ranged widely (10-18 ml/kg/min) but was overwhelmingly controlled by the individual study population's mean pVO2 (r = 0.86, p<0.00001). In contrast, the 15 negative publications were testing thresholds 199% further from their means (p = 0.0001). Likewise, of 35 EF studies (10220 patients), the thresholds in the 22 positive reports were strongly determined by study means (r = 0.90, p<0.0001). Similarly, in the 19 positives of 20 BNP studies (9725 patients): r = 0.86 (p<0.0001). Second, survival simulations always discovered a "most significant" threshold, even when there was definitely no step change in mortality. With linear increase in risk, the apparently-optimal threshold was always near the sample mean (r = 0.99, p<0.001). LIMITATIONS: This study cannot report the best threshold for any of these variables; instead it explains how common clinical research procedures routinely produce false thresholds. KEY

findingsFirst, shifting (and/or disappearance) of an apparently-optimal prognostic threshold is strongly determined by studies' average pVO2, EF or BNP. Second, apparently-optimal thresholds always appear, even with no step in prognosis.

conclusionsEmphatic therapeutic guidance based on thresholds from observational studies may be ill-founded. We should not assume that optimal thresholds, or any thresholds, exist.

Indexed as

HumansNatriuretic Peptide, BrainOxygen ConsumptionPrognosisReference ValuesStroke VolumeNatriuretic Peptide, Brain

Identifiers

PMID24475020
PMCPMC3903471
OpenAlexW2038056047

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.