Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Bioequivalence Data: Statistical Interpretation01:16

Bioequivalence Data: Statistical Interpretation

The statistical interpretation of bioequivalence data is a significant aspect of pharmaceutical research. Bioequivalence refers to the absence of any significant difference in the rate and extent to which the active ingredient in pharmaceutical products becomes available at the site of drug action when administered at the same molar dose under similar conditions. This helps determine if different drug products have similar absorption rates, ensuring their interchangeability.Statistical...
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches01:23

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
Dose-Response Relationship: Selectivity and Specificity01:25

Dose-Response Relationship: Selectivity and Specificity

Drugs exert their therapeutic effects by interacting with receptors, enzymes, or ion channels that are present throughout the human body. The strength and duration of the interaction between a drug and its target receptor are characterized by the selectivity and specificity of the drug. Selectivity refers to a drug's strong preference for its intended target over other targets. For instance, isoprenaline, a non-selective β-adrenergic agonist, interacts with both β1- and β2-adrenergic receptors...
Bias in Epidemiological Studies01:29

Bias in Epidemiological Studies

Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:
Dose Response Curve: Conventional Versus Nonmonotonic01:21

Dose Response Curve: Conventional Versus Nonmonotonic

The correlation between a drug's dosage and its impact on a biological system is a cornerstone of pharmacology and toxicology. Conventional dose–response curves, which include graded and quantal relationships, are key to this understanding. Graded dose–response curves depict the spectrum of a biological reaction to different doses within an individual, indicating that as the drug dosage increases, so does the intensity of the response. On the other hand, quantal dose–response relationships...
Strategies for Assessing and Addressing Confounding01:25

Strategies for Assessing and Addressing Confounding

Confounding is a critical issue in epidemiological studies, often leading to misleading conclusions about associations between exposures and outcomes. It occurs when the relationship between the exposure and the outcome is mixed with the effects of other factors that influence the outcome. Given that, addressing confounding is of high importance for drawing accurate inferences in research.
Confounding can be addressed at both the design phase of a study and through analytical methods after data...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Psychometric properties of the BSL-23 (English translation) and its equivalency with the BSL-23 (German): an analysis based on Item Response Theory.

BMC psychiatry·2026
Same author

Percutaneous coronary intervention plus guideline-directed medical therapy (GDMT) versus GDMT alone in adults with stable coronary artery disease.

The Cochrane database of systematic reviews·2026
Same author

Cognitive behavioural therapy for sexual concerns during menopause: evaluation of a four session protocol.

The journal of sexual medicine·2025
Same author

Number needed to isolate - a new population health metric to quantify transmission reductions from isolation interventions for infectious diseases.

Population health metrics·2024
Same author

Cross-cultural adaptation and validation to Spanish of the PANELVIEW instrument to evaluate the health guidelines development process.

Journal of clinical epidemiology·2024
Same author

Diagnostic Accuracy of SPECT for Mild Traumatic Brain Injury: A Systematic Review and Meta-analysis.

Clinical nuclear medicine·2024

Related Experiment Video

Updated: Jun 27, 2026

Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity
07:28

Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity

Published on: January 21, 2017

Reinterpreting I2 Thresholds: Toward Context-Specific Heterogeneity Assessment in Evidence Synthesis.

Arturo J Martí-Carvajal1,2, David L Streiner3

  • 1Cátedra Rectoral de Medicina Basada en la Evidencia Social Sciences Doctoral Program (Health and Society), Universidad de Carabobo Valencia Carabobo Venezuela.

Cochrane Evidence Synthesis and Methods
|June 26, 2026
PubMed
Summary

The Cochrane Handbook's I2 categorization for meta-analysis has overlapping definitions, causing ambiguity. A new framework is proposed to improve heterogeneity assessment in systematic reviews.

Keywords:
I‐squaredevidence synthesisheterogeneitymeta‐analysismeta‐regressionpatient‐important outcomessystematic review methodology

More Related Videos

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
08:12

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence
07:54

Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence

Published on: October 25, 2011

Related Experiment Videos

Last Updated: Jun 27, 2026

Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity
07:28

Psychophysically-anchored, Robust Thresholding in Studying Pain-related Lateralization of Oscillatory Prestimulus Activity

Published on: January 21, 2017

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments
08:12

A Psychophysics Paradigm for the Collection and Analysis of Similarity Judgments

Published on: March 1, 2022

Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence
07:54

Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence

Published on: October 25, 2011

Area of Science:

  • Meta-analysis and evidence synthesis methodology.
  • Statistical interpretation of heterogeneity.
  • Philosophy of science and formal logic in data analysis.

Background:

  • The Cochrane Handbook's I2 categorization is standard for interpreting heterogeneity in meta-analysis.
  • This system influences thousands of systematic reviews annually.
  • Its logical coherence and utility as a decision tool lack formal examination.

Purpose of the Study:

  • To assess if the Cochrane Handbook's I2 categorization contains overlapping definitions causing ambiguous classification.
  • To propose context-specific frameworks that maintain I2's role as a decision tool for heterogeneity exploration.

Main Methods:

  • Structured genealogical analysis of key methodological sources for I2 categorization.
  • Evaluation of I2 values against category definitions using principles of formal logic and statistical theory.
  • Development of context-specific frameworks based on patient-important outcomes.

Main Results:

  • The I2 categorization system features overlapping definitions (e.g., 50% is both moderate and high heterogeneity).
  • This violates principles of consistent and mutually exclusive classification, lacking clear justification.
  • The current system functions as an interpretive endpoint, obscuring clinical context and reducing clarity.

Conclusions:

  • The existing I2 categorization introduces ambiguity and inconsistent analytical decisions.
  • Context-specific frameworks are essential for evidence synthesis, reflecting outcome type and variability.
  • The proposed PIOHA framework aligns heterogeneity assessment with clinical relevance, preserving I2 as a decision tool.