Cited by 390Meta-analysis and systematic reviewsStatistical Methods in EpidemiologyStatistical Methods in Clinical Trials

Understanding and interpreting confidence and credible intervals around effect estimates

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Hespanhol, Luiz, Vallio, Caio Sain, Costa, Lucíola Menezes, Saragiotto, Bruno T·2019·Brazilian Journal of Physical Therapy

Abstract

Introduction Reporting confidence intervals in scientific articles is important and relevant for evidence-based practice. Clinicians should understand confidence intervals in order to determine if they can realistically expect results similar to those presented in research studies when they implement the scientific evidence in clinical practice. The aims of this masterclass are: (1) to discuss confidence intervals around effect estimates; (2) to understand confidence intervals estimation (frequentist and Bayesian approaches); and (3) to interpret such uncertainty measures.Content Confidence intervals are measures of uncertainty around effect estimates. Interpretation of the frequentist 95% confidence interval: we can be 95% confident that the true (unknown) estimate would lie within the lower and upper limits of the interval, based on hypothesized repeats of the experiment. Many researchers and health professionals oversimplify the interpretation of the frequentist 95% confidence interval by dichotomizing it in statistically significant or non-statistically significant, hampering a proper discussion on the values, the width (precision) and the practical implications of such interval. Interpretation of the Bayesian 95% confidence interval (which is known as credible interval): there is a 95% probability that the true (unknown) estimate would lie within the interval, given the evidence provided by the observed data.Conclusions The use and reporting of confidence intervals should be encouraged in all scientific articles. Clinicians should consider using the interpretation, relevance and applicability of confidence intervals in real-world decision-making. Training and education may enhance knowledge and skills related to estimating, understanding and interpreting uncertainty measures, reducing the barriers for their use under either frequentist or Bayesian approaches.

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  1. Newcombe RG. Two-sided confidence intervals for the sin- gle proportion: comparison of seven methods. Stat Med. 1998;17(8):857---872.
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Authors
Hespanhol, L., Vallio, C. S., Costa, L. M., & Saragiotto, B. T.
Affiliations
  • Amsterdam UMC Location University of Amsterdam (NL)
  • Universidade Cidade de São Paulo (BR)
Corresponding author
Hespanhol, Luiz
Venue
Brazilian Journal of Physical Therapy
Publisher
Elsevier BV
Published
2019-07
Volume
23
Issue
4
Pages
290-301
ISSN
1413-3555 (ISSN-L)
OpenAlex
W2908045944
Cited by
390
References
25
Citations by year
2026: 63 · 2025: 93 · 2024: 76 · 2023: 54 · 2022: 59 · 2021: 32 · 2020: 12 · 2019: 1
FWCI
8.53
Type
journal article
Language
en
Open access
Locations
  • Brazilian Journal of Physical Therapy (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Amsterdam UMC (VU Amsterdam) - Institutional Repository (publishedVersion)
  • Data Archiving and Networked Services (DANS) (submittedVersion)
Funders
Fundação de Amparo à Pesquisa do Estado de São Paulo (2016/09220-1, 2016/24217-7, 2017/11665-4)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
Keywords
confidence intervals, credible intervals, effect estimates, uncertainty quantification, frequentist interpretation, Bayesian interpretation, statistical significance, clinical decision-making, evidence-based practice
MeSH terms
Bayes Theorem, Humans, Uncertainty

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