Table 4.

Summary definitions of criteria for rating risk of bias domains as “good.”

Risk of bias domain	Summary criteria for “good” rating designation
Exposure measurement	Detailed and validated methods for measuring PFAS chemical(s) in indoor media(s) of interest and serum (or blood, plasma) are described, including QA/QC procedures and limit of detection.
Participant selection	Recruitment procedure is described and there is minimal concern for selection bias.
Analysis	Analysis methods and robustness of quantitative results are presented in detail, including appropriate confidence intervals, evaluation of variability, and handling of missing data.

Adapted from U.S. EPA’s Systematic Review Protocol for the PFBA, PFHxA, PFHxS, PFNA, and PFDA IRIS Assessments (draft, 2019), Mandrioli et al. (2018), VanNoy et al. (2018), and Bero et al. (2018).