Table 3.

Adjusted OR (95% CIs) from the weighted quantile sum (WQS) regressions for ACPA positivity

Threshold of ACPA positivity	OR (95% CI)	Weight
		SO2	NO2	PM2.5
20 units/ml (N positive = 786)	1.36 (1.10–1.69)	0.12	0.00	0.88
40 units/ml (N positive = 292)	1.43 (1.05–1.96)	0.28	0.18	0.54
60 units/ml (N positive = 134)	1.33 (0.85–2.10)	0.22	0.14	0.64

Adjusted ORs are per increase of an interquartile range of the logarithmically transformed industrial air pollutants. Variables adjusted for include age, sex, ancestry, smoking, and annual income level