Turkiye Klinikleri Journal of Biostatistics

.: ORIGINAL RESEARCH
The Effect of Different Effect Size Measures on Mediation Analysis Performance: A Methodological Study
Farklı Etki Büyüklüğü Ölçülerinin Aracılık Analizi Performansına Etkisi: Metodolojik Bir Çalışma
Nihan ÖZEL ERÇELa , Gülhan TEMELa , Cemil ÇOLAKb
aMersin University Faculty of Medicine, Department of Biostatistics and Medical Information, Mersin, Türkiye
bİnönü University Faculty of Medicine, Department of Biostatistics and Medical Information, Malatya, Türkiye
Turkiye Klinikleri J Biostat. 2024;16(3):140-9
doi: 10.5336/biostatic.2024-107203
Article Language: EN
Full Text
ABSTRACT
 Objective: In mediation analysis, the use of effect size measures is extremely important to understand the strength and direction of the relationship between variables in depth and to determine the importance of the mediating variable effect. In the literature, it is seen that there are few studies comparing the performance of effect size measures for mediation analysis. The aim of this study is to investigate the relationships between continuous variables and to compare the performances of effect size measures for mediation model. Material and Methods: In line with the objective of the study, the performance of effect size measures for the mediation model was examined through a simulation study, considering different sample sizes and small, medium, and large effect sizes. The comparison of effect size measures for the mediation model was conducted by examining bias values. Results: For the mediation model, it was observed that R2 , as a measure of explained variance, had the least bias across all scenarios considered in the simulation. While mediation ratio measures required a minimum sample size of 500, R2 as a measure of explained variance exhibited good performance even with smaller sample sizes, such as 100. Conclusion: In models involving mediator variables, it is recommended to use alternative effect size measures in research, in addition to a single measure, to comprehensively capture the strength of the relationship between variables.

Keywords: Mediation analysis; mediator variable; effect size; mediation proportion; explained variance
ÖZET
 Amaç: Aracı değişken içeren modellerde, değişkenler arasındaki ilişkinin gücünü ve yönünü derinlemesine anlamanın yanı sıra aracı değişken etkisinin önemini ortaya koymak için etki büyüklüğü ölçülerine yer verilmesi son derecede önemlidir. Literatürde aracılık analizi için etki büyüklüğü ölçülerinin performanslarının karşılaştırmalı olarak ele alındığı çalışma sayısının az olduğu görülmektedir. Bu çalışmanın amacı, sürekli türdeki değişkenler arasındaki ilişkilerin araştırılması ve aracılık modeli için etki büyüklüğü ölçülerinin performanslarının karşılaştırılmasıdır. Gereç ve Yöntemler: Çalışmanın amacı doğrultusunda, farklı örnek genişliklerinde ve küçük, orta, geniş etki büyüklüğü durumlarında aracılık modeli için etki büyüklüğü ölçülerinin performansları bir simülasyon çalışması ile incelenmiştir. Aracılık modeli için etki büyüklüğü ölçülerinin performans karşılaştırması yanlılık değerleri göz önünde bulundurularak yapılmıştır. Bulgular: Aracılık modeli için simülasyonda ele alınan tüm senaryolarda R2 açıklanan varyans ölçülerinin en az yanlılığa sahip olduğu görülmüştür. Aracılık oran ölçüleri için en az 300 örnek genişliği gerekirken, R2 açıklanan varyans ölçüsünün 100 gibi daha küçük örnek genişliklerinde de iyi bir performansa sahip olduğu görülmüştür. Sonuç: Aracı değişkenli modellerde değişkenler arasındaki ilişkinin gücünün daha kapsamlı şekilde ele alınabilmesi için tek bir etki büyüklüğü ölçüsü yerine alternatif ölçülerin de araştırmalarda kullanılması önerilmektedir.

Anahtar Kelimeler: Aracılık analizi; aracı değişken; etki büyüklüğü; aracılık oranı; açıklanan varyans
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