Evidence map›Paper›PMID 21053091›Full record

Trial reportJournal of general internal medicine2011

Does prevalence matter to physicians in estimating post-test probability of disease? A randomized trial.

Thomas Agoritsas, Delphine S Courvoisier, Christophe Combescure, Marie Deom, Thomas V Perneger

Abstract readComparative StudyRandomized Controlled Trial
In one paragraph

Trial report in Journal of general internal medicine, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
22citing papers in PubMed, 1 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

22 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Trial
  3. Trial
  4. Trial
  5. Trial
  6. Article
  7. Article
  8. Article
  9. Article
  10. Article
  11. Review
  12. Article
  13. Article
  14. Article
  15. Review
  16. Article
  17. Article
  18. Bayesian reasoning in residents' preliminary diagnoses.Cognitive research: principles and implications · 2016
    Article
  19. Article
  20. Article
4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

5 authors.

Thomas AgoritsasDivision of Clinical Epidemiology, University Hospitals of Geneva, Gabrielle Perret-Gentil 6, 1211, Geneva 14, Switzerland. thomas.agoritsas@hcuge.ch
Delphine S Courvoisier
Christophe Combescure
Marie Deom
Thomas V Perneger

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe probability of a disease following a diagnostic test depends on the sensitivity and specificity of the test, but also on the prevalence of the disease in the population of interest (or pre-test probability). How physicians use this information is not well known.

objectiveTo assess whether physicians correctly estimate post-test probability according to various levels of prevalence and explore this skill across respondent groups.

designRandomized trial.

participantsPopulation-based sample of 1,361 physicians of all clinical specialties.

interventionWe described a scenario of a highly accurate screening test (sensitivity 99% and specificity 99%) in which we randomly manipulated the prevalence of the disease (1%, 2%, 10%, 25%, 95%, or no information). MAIN MEASURES: We asked physicians to estimate the probability of disease following a positive test (categorized as <60%, 60-79%, 80-94%, 95-99.9%, and >99.9%). Each answer was correct for a different version of the scenario, and no answer was possible in the "no information" scenario. We estimated the proportion of physicians proficient in assessing post-test probability as the proportion of correct answers beyond the distribution of answers attributable to guessing. KEY

resultsMost respondents in each of the six groups (67%-82%) selected a post-test probability of 95-99.9%, regardless of the prevalence of disease and even when no information on prevalence was provided. This answer was correct only for a prevalence of 25%. We estimated that 9.1% (95% CI 6.0-14.0) of respondents knew how to assess correctly the post-test probability. This proportion did not vary with clinical experience or practice setting.

conclusionsMost physicians do not take into account the prevalence of disease when interpreting a positive test result. This may cause unnecessary testing and diagnostic errors.

Indexed as

Diagnostic ErrorsPhysiciansPrevalenceProbabilityAdultDiagnostic Tests, RoutineFemaleHumansMaleMiddle AgedModels, StatisticalSurveys and Questionnaires

Identifiers

PMID21053091
PMCPMC3055966

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.