Evidence map›Paper›PMID 20719825›Full record

SynthesisBMJ (Clinical research ed.)2010

Definition, reporting, and interpretation of composite outcomes in clinical trials: systematic review.

Gloria Cordoba, Lisa Schwartz, Steven Woloshin, Harold Bae, Peter C Gøtzsche

Abstract readSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in BMJ (Clinical research ed.), 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 147 papers, 26 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
147citing papers in PubMed, 26 pooled it
–field-weighted citation impact
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

147 citing papers in PubMed, 26 syntheses or guidelines pooled it.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Pooled it
  5. Pooled it
  6. Pooled it
  7. Pooled it
  8. Pooled it
  9. Pooled it
  10. Pooled it
  11. Pooled it
  12. Pooled it
  13. Pooled it
  14. Needle size for vaccination procedures in children and adolescents.The Cochrane database of systematic reviews · 2018
    Pooled it
  15. Cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation: a meta-analysis of randomized controlled trials.Clinical research in cardiology : official journal of the German Cardiac Society · 2018
    Pooled it
  16. Pooled it
  17. Industry sponsorship and research outcome.The Cochrane database of systematic reviews · 2017
    Pooled it
  18. Pooled it
  19. Pooled it
  20. Pooled it

87 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors.

Gloria CordobaNordic Cochrane Centre, Rigshospitalet and University of Copenhagen, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
Lisa Schwartz
Steven Woloshin
Harold Bae
Peter C Gøtzsche

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo study how composite outcomes, which have combined several components into a single measure, are defined, reported, and interpreted.

designSystematic review of parallel group randomised clinical trials published in 2008 reporting a binary composite outcome. Two independent observers extracted the data using a standardised data sheet, and two other observers, blinded to the results, selected the most important component.

resultsOf 40 included trials, 29 (73%) were about cardiovascular topics and 24 (60%) were entirely or partly industry funded. Composite outcomes had a median of three components (range 2-9). Death or cardiovascular death was the most important component in 33 trials (83%). Only one trial provided a good rationale for the choice of components. We judged that the components were not of similar importance in 28 trials (70%); in 20 of these, death was combined with hospital admission. Other major problems were change in the definition of the composite outcome between the abstract, methods, and results sections (13 trials); missing, ambiguous, or uninterpretable data (9 trials); and post hoc construction of composite outcomes (4 trials). Only 24 trials (60%) provided reliable estimates for both the composite and its components, and only six trials (15%) had components of similar, or possibly similar, clinical importance and provided reliable estimates. In 11 of 16 trials with a statistically significant composite, the abstract conclusion falsely implied that the effect applied also to the most important component.

conclusionsThe use of composite outcomes in trials is problematic. Components are often unreasonably combined, inconsistently defined, and inadequately reported. These problems will leave many readers confused, often with an exaggerated perception of how well interventions work.

Indexed as

Treatment OutcomeData Interpretation, StatisticalRandomized Controlled Trials as TopicResearch Design

Identifiers

PMID20719825
PMCPMC2923692

What OpenQuestion holds

Textmetadata
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.