Association of electronic cigarette use with chronic kidney disease in NHANES 2017–2020: A replication study

Combustible cigarette (CC) smoking is a modifiable risk factor for chronic kidney disease (CKD), but the CKD risk associated with electronic cigarette (EC) use, relative to CC use or nonuse, is unclear. We read with interest a recent analysis (Li et al., 2025) of the NHANES 2017–2020 database that evaluated this research question. In the course of verifying the results, we identified multiple concerns in the reported methodology including a) not a priori segmenting into CC current, former, and never use to minimize confounding between CC and EC use in subsequent analysis; b) unclear rationale for excluding ~80% of the available sample; and c) performing a sensitivity analysis on an EC cohort with n=1 harm events. The present replication study indicates that, after segmenting for CC use history and adjusting for covariates, particularly former smoking, there was no association between EC current use (past 5 days) and CKD risk in this NHANES population. This replication study highlights how precise segmentation and characterization of exposure to all tobacco products is required for accurate analysis of cross-sectional studies and suggests metrics for incorporation into future waves of NHANES.