Classification of mediation analysis methodology in clinical research – Pubrica

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CLASSIFICATION OF MEDIATION ANALYSIS METHODOLOGY IN CLINICAL RESEARCH An Academic presentation by Dr. Nancy Agens, Head, Technical Operations, Pubrica Group:www.pubrica.com Email: [email protected]

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• Mediation Analysis as a method to connect the causal-effect relation in being used popularly in Medical writing for clinical research, especially since the last decade. • The type of Mediation Analysis model is dependent on the needs of the study and each has its own set of advantages and disadvantages. Full Information: https://bit.ly/3hdJCYa Reference: https://pubrica.com/services/research-services/ Why pubrica? When you order our services, we promise you the following – Plagiarism free, always on Time, outstanding customer support, written to Standard, Unlimited Revisions support and High-quality Subject Matter Experts. Contact us : Web: https://pubrica.com/ Blog: https://pubrica.com/academy/ Email: [email protected] WhatsApp : +91 9884350006 United Kingdom: +44-74248 10299

Transcript of Classification of mediation analysis methodology in clinical research – Pubrica

Page 1: Classification of mediation analysis methodology in clinical research – Pubrica

CLASSIFICATION OF MEDIATION ANALYSIS METHODOLOGY IN CLINICAL RESEARCH

An Academic presentation byDr. Nancy Agens, Head, Technical Operations, Pubrica Group: www.pubrica.comEmail: [email protected]

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In BriefWhat is Mediation AnalysisClassification of Mediation Analysis Methodology ConclusionFuture Scopes

Outline

Today's Discussion

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Mediation Analysis as a method to connect the causal-effect relation in being used popularly in Medical writing for clinical research, specially since

the last decade. The type of Mediation Analysis model is dependent on the needs of the study and each has its own set of advantages and

disadvantages. Since there is significant heterogeneity in the manner it is used, there is need for methodological uniformity.

In Brief

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Mediation analysis (MA) is a form of statistical analysis and is very commonly used in epidemiology, psychology, sociology, and medicine by Scientific Medical Writing Companies.

It attempts to predict the relation between the antecedent variable and the outcome variable by Clinical Research Services.

In other words, Medical Writing in Clinical Research use MAto try and find methodology by which outcome is related to exposure.

Thus, it is useful in both interventional and observational studies while scientific research paper writing or Medical Writing for Clinical Trials.

What is Mediation Analysis?

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Research paper writing help use mediation model as a causal model where mediator is presumed to cause the effect, while the vice versa is not true.

Statistics is used to evaluate whether the presumption of the MA is correct or not.

Scientific writing help use this information while research paper writing and it is useful to find the association with causation.

This helps understand the disease aetiology better and this information is used to improve or alter existing treatment and management modality.

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In this method, separate regression models are used for the antecedent and the outcome variable in clinical medical research. E.g.

Baron and Kenny’s framework is commonly used byMedical Research Companies.

X is the causal variable and Y is the outcome in the absence of any mediation as per the below representation. Path C is the total effect.

1. TRADITIONAL APPROACHES SINGLE MEASURE: -Classification of Mediation Analysis Methodology

Contd..

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Mediating variable M in the below figure is the process or intervention variable.

Path C´ in this figure is the direct effect. When the path from X to Y is reduced but above zero, there is partial mediation, while when C´ becomes zero, there is complete mediation.

There are four steps in the Baron and Kenny’s model in establishing mediation.

Contd..

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Step 1: - To show that the antecedent variable correlates with the outcome variable.

Step 2: - To show that the antecedent variable correlates with the mediator.

Step 3: - To show that the mediator affects the outcome variable.

Step 4: - To establish that the mediator completely mediates the causal- effect relationship.

Total effect = direct effect + indirect effect ORC = C´ + ab

Complete mediation is proved when all the four steps are met, while partial mediation is indicated if Step 4 is not met.

Contd..

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Contd..

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2. COUNTERFACTUAL APPROACHES SINGLE MEDIATOR: -

Lewis’s 1973 counterfactual analysis is based on the understanding that, if an antecedent event is the complete causal factor for the effect, then, there would not be the effect if there is no antecedent event.

Medical Writing CRO use different regression models for the antecedent and the outcome. Causal contrast is highlighted between the exposed and the non-exposed.

In the causal-effect model, when there are multiple mediators that need to be evaluated, one can consider one mediator at a time.

This is possible only when mediators do not affect each other.

Contd..

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However, if we need to evaluate several mediators simultaneously or in cases where mediators affect each other, we need to use either parallel or serial MA.

Contd..

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Mediation with single mediator M, A is exposure, Y is the outcome and C is the confounder.

Contd..

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Mediation with two mediators M(1), M(2), A is exposure, Y is outcome and C is the confounder.

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Mediators with unknown common cause, where mediators do not affect each other.

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3. P ARALLEL MEDIATORS:

Medical Writing for Clinical research uses parallel multiple mediators that need to be evaluated at the same time.

Regression model is used for all mediators and separate models are used for different mediators.

4. S ERIAL OR SEQUENTIAL MEDIATION: -

Serial mediation is used when mediators act one after the other for the outcome or the chain reaction.

Contd..

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MA is based on strong assumptions that need to be discussed to avoid misinterpretations.

Planning MA in advance is preferred as it helps in adjustingin the methodologies to account for appropriate sample size, key confounders, and measurement errors in mediators.

There is considerable heterogeneity in the planning, conduct and reporting of MA, necessitating the need to have uniform and consensus-based guidelines on the methodology.

Future Scopes

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