Table 2.

Maternal exposure to NO₂ (μg/m³) and concordance between NO₂ levels [mean ± SD (5th, 50th, 95th percentiles)] estimated by the nearest-AQMS model and the TAG model, for various exposure windows and buffer sizes considered around AQMSs.

Area exposure window	Nearest-AQMS model (5-km buffer)		TAG model (5-km buffer)			Between-model agreement
						Distancea < 5 km				Distancea < 2 km				Distancea < 1 km
	n	NO2 levels	n	NO2 levels	p-Valueb	n	r	c	κ	n	r	c	κ	n	r	c	κ
Both areas
First trimester	770	28.8 ± 10.8 (11.3, 30.1, 43.6)	773	23.7 ± 6.2 (13.6, 23.0, 34.6)	10−4	767	0.67	61	0.41	429	0.70	62	0.43	158	0.83	75	0.63
Second trimester	771	29.0 ± 10.9 (11.5, 30.0, 43.9)	770	24.1 ± 6.5 (13.6, 23.6, 34.4)	10−4	766	0.69	60	0.40	426	0.72	58	0.37	156	0.82	73	0.60
Third trimester	770	28.1 ± 11.1 (10.4, 29.4, 44.2)	772	23.3 ± 6.8 (12.5, 22.8, 34.7)	10−4	767	0.74	63	0.44	428	0.79	68	0.52	155	0.87	79	0.68
Whole pregnancy	776	28.6 ± 10.0 (13.3, 32.4, 41.8)	770	23.7 ± 5.0 (16.1, 23.8, 32.3)	10−4	770	0.65	63	0.44	428	0.70	64	0.46	157	0.85	73	0.59
Poitiers area
First trimester	310	25.6 ± 11.9 ( 9.3, 21.6, 43.0)	316	20.9 ± 6.3 (12.0, 20.4, 35.8)	< 10−3	310	0.61	59	0.38	181	0.65	57	0.36	75	0.89	83	0.74
Second trimester	311	25.2 ± 11.6 (10.1, 22.2, 42.7)	315	20.4 ± 6.1 (11.8, 19.9, 32.0)	10−4	311	0.61	56	0.34	179	0.65	57	0.36	74	0.83	63	0.45
Third trimester	310	23.9 ± 11.3 ( 8.5, 21.7, 42.0)	315	19.5 ± 6.3 (11.5, 19.0, 30.8)	10−4	310	0.66	62	0.43	179	0.72	67	0.51	73	0.86	78	0.67
Whole pregnancy	316	24.9 ± 10.6 (12.4, 18.8, 40.5)	316	20.3 ± 4.7 (14.7, 19.2, 30.0)	0.12	316	0.55	56	0.34	181	0.62	58	0.37	75	0.87	68	0.52
Nancy area
First trimester	460	31.0 ± 9.5 (13.6, 31.3, 44.1)	457	25.7 ± 5.2 (17.9, 25.5, 34.6)	10−4	457	0.67	55	0.32	248	0.69	58	0.36	83	0.72	59	0.39
Second trimester	460	31.6 ± 9.6 (14.1, 32.0, 44.4)	455	26.7 ± 5.5 (18.5, 26.6, 35.6)	10−4	455	0.70	58	0.37	247	0.73	65	0.48	82	0.74	66	0.49
Third trimester	460	30.9 ± 10.0 (13.5, 31.4, 45.0)	457	26.0 ± 5.8 (17.5, 25.7, 36.2)	10−4	457	0.74	61	0.41	249	0.78	67	0.51	82	0.82	76	0.63
Whole pregnancy	460	31.2 ± 8.7 (16.9, 34.4, 42.4)	454	26.1 ± 3.7 (20.8, 25.7, 32.8)	10−4	454	0.66	64	0.46	247	0.69	64	0.47	82	0.66	71	0.56

Abbreviations: r, Pearson correlation coefficient; c, concordance percentage (based on NO₂ levels categorized in tertiles); κ, kappa coefficient (based on NO₂ levels categorized in tertiles).

^aMaximal distance between home address and the nearest AQMS (buffer size).

^bp-Value of Kruskal–Wallis rank test comparing the exposure levels from the two models.