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

Randomized Experiments01:13

Randomized Experiments

6.3K
The randomization process involves assigning study participants randomly to experimental or control groups based on their probability of being equally assigned. Randomization is meant to eliminate selection bias and balance known and unknown confounding factors so that the control group is similar to the treatment group as much as possible. A computer program and a random number generator can be used to assign participants to groups in a way that minimizes bias.
Simple randomization
Simple...
6.3K
Strategies for Assessing and Addressing Confounding01:25

Strategies for Assessing and Addressing Confounding

596
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...
596
Confounding in Epidemiological Studies01:27

Confounding in Epidemiological Studies

1.1K
Confounding in statistical epidemiology represents a pivotal challenge, referring to the distortion in the perceived relationship between an exposure and an outcome due to the presence of a third variable, known as a confounder. This variable is associated with both the exposure and the outcome but is not a direct link in their causal chain. Its presence can lead to erroneous interpretations of the exposure's effect, either exaggerating or underestimating the true association. This...
1.1K
Regression Toward the Mean01:52

Regression Toward the Mean

6.3K
Regression toward the mean (“RTM”) is a phenomenon in which extremely high or low values—for example, and individual’s blood pressure at a particular moment—appear closer to a group’s average upon remeasuring. Although this statistical peculiarity is the result of random error and chance, it has been problematic across various medical, scientific, financial and psychological applications. In particular, RTM, if not taken into account, can interfere when...
6.3K
Mechanistic Models: Compartment Models in Individual and Population Analysis01:23

Mechanistic Models: Compartment Models in Individual and Population Analysis

359
Mechanistic models are utilized in individual analysis using single-source data, but imperfections arise due to data collection errors, preventing perfect prediction of observed data. The mathematical equation involves known values (Xi), observed concentrations (Ci), measurement errors (εi), model parameters (ϕj), and the related function (ƒi) for i number of values. Different least-squares metrics quantify differences between predicted and observed values. The ordinary least...
359
Factorial Design02:01

Factorial Design

13.1K
Factorial Analysis is an experimental design that applies Analysis of Variance (ANOVA) statistical procedures to examine a change in a dependent variable due to more than one independent variable, also known as factors. Changes in worker productivity can be reasoned, for example, to be influenced by salary and other conditions, such as skill level. One way to test this hypothesis is by categorizing salary into three levels (low, moderate, and high) and skills sets into two levels (entry level...
13.1K

You might also read

Related Articles

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

Sort by
Same author

Tool for Converting ADHD Rating Scales Scores Based on Individual Participant Data from 53 Randomized Controlled Trials of ADHD Medications.

Journal of child and adolescent psychopharmacology·2026
Same author

Dental caries and periodontal status in children and adolescents with type 1 diabetes mellitus: an umbrella review.

European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry·2026
Same author

Comparison of overall survival across treatment modalities for oesophageal, gastroesophageal, and gastric cancer: protocol for a systematic review and network meta-analysis.

Systematic reviews·2026
Same author

Response to: Matters Arising in relation to "Evaluating agreement between individual nutrition randomised controlled trials and cohort studies - a meta-epidemiological study".

BMC medicine·2026
Same author

Is it efficacy or just improvement? A re-evaluation of the meta-analysis presented by Zhang et al.

Journal of affective disorders·2026
Same author

Comparative efficacy and tolerability of antidopaminergic and muscarinic antipsychotics for acute schizophrenia: a network meta-analysis of randomised controlled trials indexed in international English and Chinese databases.

Lancet (London, England)·2026
Same journal

Digital cognitive-behavioural therapy to reduce suicidal ideation and behaviours: a systematic review and meta-analysis of individual participant data.

Evidence-based mental health·2022
Same journal

Risk prediction model for cardiovascular diseases in adults initiating pharmacological treatment for attention-deficit/hyperactivity disorder.

Evidence-based mental health·2022
Same journal

Carpe diem.

Evidence-based mental health·2022
Same journal

Associations between antipsychotics and risk of violent crimes and suicidal behaviour in personality disorder.

Evidence-based mental health·2022
Same journal

COP27 climate change conference: urgent action needed for Africa and the world.

Evidence-based mental health·2022
Same journal

Can we mitigate the psychological impacts of social isolation using behavioural activation? Long-term results of the UK BASIL urgent public health COVID-19 pilot randomised controlled trial and living systematic review.

Evidence-based mental health·2022
See all related articles

Related Experiment Video

Updated: May 1, 2026

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment
08:36

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment

Published on: April 19, 2024

1.4K

Demystifying fixed and random effects meta-analysis.

Adriani Nikolakopoulou1, Dimitris Mavridis, Georgia Salanti

  • 1Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, , Ioannina, Greece.

Evidence-Based Mental Health
|April 3, 2014
PubMed
Summary
This summary is machine-generated.

Choosing between fixed-effect and random-effects models in meta-analysis is crucial. Understanding their assumptions and implications ensures accurate interpretation of summary results for evidence synthesis.

More Related Videos

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

2.9K
Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI
06:26

Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI

Published on: November 27, 2019

82.5K

Related Experiment Videos

Last Updated: May 1, 2026

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment
08:36

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment

Published on: April 19, 2024

1.4K
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
04:35

Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach

Published on: July 3, 2020

2.9K
Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI
06:26

Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI

Published on: November 27, 2019

82.5K

Area of Science:

  • Biostatistics
  • Evidence Synthesis
  • Medical Research Methodology

Background:

  • Systematic reviews frequently require selecting between fixed-effect and random-effects models for meta-analysis.
  • These models differ in their underlying assumptions regarding treatment effects across studies.

Purpose of the Study:

  • To elucidate the assumptions inherent in both fixed-effect and random-effects models.
  • To explain the implications of these assumptions on the interpretation of meta-analysis summary results.

Main Methods:

  • Discussion of the core assumptions of fixed-effect and random-effects meta-analysis models.
  • Illustration of model implications using two examples from a published meta-analysis.

Main Results:

  • Meta-analytic approaches can produce similar or divergent results.
  • Even with similar results, summary estimates necessitate distinct interpretations based on the model used.

Conclusions:

  • Model selection should prioritize the clinical relevance of underlying assumptions.
  • Researchers must consider the impact of the chosen model on findings interpretation and utilize prediction intervals for random-effects models.