a factor that most workers...在整句话中是什么成分

By and large, however, most reports on age patterning in hypoplasia occurrence indicate a peak in defects at 2 to 4 years of age, regardless of geographic or ecological setting, a factor that most workers have attributed to nutritional stresses of postweaning diets.

句中a factor that most workers have attributed to nutritional stresses of postweaning diets.是什么成分？

a factor that most workers have attributed to nutritional stresses of postweaning diets.

名词+定语从句或同位语从句，对前面句子的内容做总结。传统语法称这个名词词组为前面句子的同位语。现代语法称为句子的补充语（supplement），或补充性状语。