Table 2

Association between PFAAs and self-report memory impairment in logistic regression for a doubling PFAA concentration, by quintiles of PFAAs and in ordinal regression (n=21 024)

Range (ng/ml)Adjusted OR and 95% CI*
PFOS0.93 (0.90 to 0.96)
 1st quintile0.25–14.4Ref.
 2nd quintile14.5–20.40.96 (0.87 to 1.07)
 3rd quintile20.5–27.10.86 (0.78 to 0.96)
 4th quintile27.2–37.20.87 (0.78 to 0.96)
 5th quintile37.3–759.20.85 (0.76 to 0.94)
Trend<0.001
Ordinal regression0.95 (0.93 to 0.98)
PFOA0.96 (0.94 to 0.98)
 1st quintile0.25–14.0Ref.
 2nd quintile14.1–27.00.88 (0.79 to 0.97)
 3rd quintile27.1–53.80.83 (0.75 to 0.92)
 4th quintile53.9–118.10.79 (0.71 to 0.88)
 5th quintile118.3–224120.79 (0.71–0.88)
Trend<0.001
Ordinal regression0.97 (0.96 to 0.98)
PFNA0.96 (0.91 to 1.00)
 1st quintile0.25–0.90Ref.
 2nd quintile1.0–1.20.86 (0.78 to 0.96)
 3rd quintile1.3–1.40.87 (0.77 to 0.98)
 4th quintile1.5–1.90.86 (0.77 to 0.95)
 5th quintile2.0–28.60.89 (0.80 to 0.99)
Trend0.053
Ordinal regression0.97 (0.94–1.01)
PFHxS0.96 (0.93–0.99)
 1st quintile0.25–1.7Ref.
 2nd quintile1.8–2.61.01 (0.91–1.12)
 3rd quintile2.7–3.61.02 (0.91–1.13)
 4th quintile3.7–5.60.93 (0.84–1.04)
 5th quintile5.7–232.60.89(0.79–0.99)
Trend0.009
Ordinal regression0.97 (0.94–0.99)

  • *Model adjusted for age (1-year age bands), ethnicity, gender and school level (categorical), household income (categorical), physical activity, alcohol consumption (categorical, none/<1 drink/month, <1 drink/week, few drinks/week, 1–3 drinks/day, >3 drinks/day, undetermined) and cigarette smoking (categorical, never, former, <10 cigarette/day, 12–20 cigarette/day, 20+ cigarette/day).

  • PFAA, perfluoroalkyl acids; PFHxS, perfluorohexane sulfonate; PFNA, perfluorononanoic acid; PFOA, perfluorooctanate; PFOS, perfuorooctane sulfonate.