Associations of per- and polyfluoroalkyl substances (PFAS) and their mixture with risk of rheumatoid arthritis in the U.S. adult population

Table 4 Mean adjusted associations from WQS logistic regression model with 100 repeated holdouts between per- and polyfluoroalkyl substance (PFAS) mixture and odds of rheumatoid arthritis (RA)

Abbreviations WQS, weighted quantile sum; SD, standard deviation; CI, confidence interval; OR, odds ratio
Notes All chemicals were log₂ transformed to reduce skewness in the distribution of the concentrations
^a The associations are derived from a stratified WQS logistic regression model allowing for sex-specific weights and including an interaction term WQS*sex. The model was run with 100 repeated holdouts using 40% of the data as training and 60% as validation set. The models were adjusted for age, sex, ethnicity, educational attainment, BMI, poverty income ratio, alcohol consumption, and physical activity
^b The mean OR over the 100 repeated holdouts is presented with its 95% confidence interval
^c The number of adjusted ORs from the 100 repeated holdouts that were below 1
^d Adjusted OR for male (b₁) is the OR for the WQS index for the reference group (male = 0), and the adjusted OR for female (b₂), which is the comparison group (female = 1) is calculated based on the sum of the OR for the WQS*sex interaction term and the OR for the WQS index for the reference group (b₂ = b₁ + b₁₂). The ORs are calculated based on exponentiation of betas

ISSN: 1476-069X