The crude and adjusted odds ratio with 95% confidence interval of attention deficit hyperactivity disorder and exposure to perfluorinated compounds.

Abbreviations: ADHD, attention deficit hyperactivity disorder; PFOS, perfluorooctane sulfonate; PFOA, perfluorooctanoic acid; PFNA, perfluorononanoic acid; LOD, limit of detection.
aAdjusted for maternal active smoking, parity, and gestational age at birth.
bOdds ratio is calculated for 1 ng/ml increase in umbilical cord serum concentration.
cOdds ratio is calculated for PFOS and PFOA concentrations at or above the 75th percentile (75th percentile for PFOS and PFOA were 9,1 ng/ml and 2,4 ng/ml, respectively).
dOdds ratio is calculated for PFNA concentrations at or above the LOD (0.2 ng/ml).