Fig. 2: Summary of mixture methods used in overall effect estimation from included studies by study design.

Panel A is the frequency of mixture methods in studies that applied one mixture method grouped by modeling strategy and study design. Mixture methods appeared only once in studies were excluded. Panel B is the frequency of mixture methods combination in studies that applied two or more mixture methods categorized by study design. Mixture methods combination appeared only once in studies were excluded. PCA Principal component analysis, WQS Weighted quantile sum, BKMR Bayesian kernel machine regression, TEQ toxicity equivalent quantity.