Ulcerative Colitis and Perfluorooctanoic Acid (PFOA) in a Highly Exposed Population of Community Residents and Workers in the Mid-Ohio Valley

http://dx.doi.org/10.1289/ehp.1206449



Table 3. Overall retrospective survival analysis results based on follow-up from 1952 through 2008–2011 [RR (95%)].a
  Q2 vs. Q1b Q3 vs. Q1 Q4 vs. Q1 ptrend of log cumulative exposure
Q, quartile.
aFollow up continued until the date of the last survey, the date of diagnosis for each individual outcome being evaluated, or on the date of death, whichever occurred first. bCut points for these quartiles varied by disease analyzed, as they were based on dividing the cases equally by quartiles. For example for ulcerative colitis, the cut points were 158, 586, and 3,500 ng/mL/year, which for a 50-year-old participant would correspond to average exposure of approximately < 3, 3–11, 11–70, and > 70 ng/mL/ year. cIncludes self-reported cases listed as verified as either type 1 diabetes or insulin-dependent diabetes. dRestricted to those self-reported cases specifically validated for type 1 diabetes.
Unlagged exposure        
Ulcerative colitis 1.76 (1.04, 2.99) 2.63 (1.56, 4.43) 2.86 (1.65, 4.96) < 0.0001
Crohn’s disease 1.25 (0.61, 2.58) 1.15 (0.55, 2.41) 1.00 (0.48, 2.09) 0.73
Rheumatoid arthritis 1.24 (0.85, 1.79) 1.40 (0.96, 2.03) 0.99 (0.68, 1.43) 0.84
Type 1 diabetes–broadc 0.68 (0.29, 1.58) 0.53 (0.22, 1.30) 0.54 (0.22, 1.33) 0.84
Type 1 diabetes–narrowd 0.83 (0.25, 2.78) 1.41 (0.40, 4.95) 0.88 (0.25, 3.06) 0.68
Lupus 1.49 (0.68, 3.34) 1.01 (0.44, 2.30) 0.71 (0.31, 1.65) 0.94
Multiple sclerosis 0.85 (0.44, 1.63) 1.56 (0.81, 3.00) 1.26 (0.65, 2.42) 0.22
10-year lagged exposure        
Ulcerative colitis 1.71 (0.89, 3.27) 2.05 (1.07, 3.91) 3.05 (1.56, 5.96) < 0.0001
Crohn’s disease 0.80 (0.32,1.99) 0.97 (0.36, 2.60) 0.69 (0.26, 1.82) 0.79
Rheumatoid arthritis 1.53 (0.61, 2.58) 1.73 (1.10, 2.71) 1.35 (0.87, 2.11) 0.73
Type 1 diabetes–broadc 0.42 (0.09, 2.00) 0.70 (0.14, 0.35) 0.38 (0.08, 1.93) 0.84
Type 1 diabetes–narrowd 0.50 (0.05, 4.90) 1.32 (0.14, 12.40) 0.71 (0.07, 7.14) 0.65
Lupus 0.79 (0.27, 2.34) 1.26 (0.40, 4.03) 0.61 (0.19, 1.91) 0.93
Multiple sclerosis 1.16 (0.54, 2.47) 1.62 (0.75, 3.52) 1.32 (0.61, 2.84) 0.59