. 2023 Jul 28;131(7):077010. doi: 10.1289/EHP12215

Table 5.

Associations of air pollutants with risk of all-cause mortality in individuals with IBD, CD, and UC in the UK Biobank study, mean follow-up of 12 y.

Air pollutants in quartiles ( ${μ g / m}^{3}$ )	IBD ( $lowercase italic n equals 4708$ )					CD ( $lowercase italic n equals 1485$ )			UC ( $lowercase italic n equals 3233$ )
Air pollutants in quartiles ( ${μ g / m}^{3}$ )	Cases/person-years	HR (95% CI)^a	p-Value	HR (95% CI)^b	p-Value^c	Cases/person-years	HR (95% CI)^b	p-Value	Cases/person-years	HR (95% CI)^b	p-Value
${NO}_{x}$
Per IQR (15.6)	—	1.12 (1.03, 1.21)	0.008	1.10 (1.01, 1.20)	0.036	—	1.04 (0.89, 1.21)	0.637	—	1.14 (1.01, 1.29)	0.030
Q1 ( $19.7 to less than 34.8$ )	82/13,835	Ref	—	Ref	—	28/4,425	Ref	—	54/9,360	Ref	—
Q2 ( $34.8 to less than 42.0$ )	118/13,701	1.51 (1.14, 2.01)	0.004	1.44 (1.08, 1.91)	0.012	41/4,165	1.57 (0.96, 2.54)	0.070	77/9,510	1.37 (0.97, 1.95)	0.076
Q3 ( $42.0 to less than 50.4$ )	114/13,580	1.49 (1.12, 1.98)	0.006	1.39 (1.04, 1.85)	0.026	39/4,422	1.33 (0.82, 2.18)	0.250	75/9,013	1.41 (0.99, 2.01)	0.058
Q4 (50.4–247.5)	106/13,788	1.53 (1.15, 2.04)	0.004	1.39 (1.04, 1.86)	0.025	36/4,178	1.30 (0.79, 2.14)	0.301	70/9,489	1.37 (0.95, 1.96)	0.088
p-Trend	—	—	0.007	—	0.049	—	—	0.481	—	—	0.106
${NO}_{2}$
Per IQR (10.4)	—	1.18 (1.06, 1.31)	0.003	1.16 (1.03, 1.29)	0.010	—	1.17 (0.98, 1.41)	0.079	—	1.13 (0.98, 1.30)	0.091
Q1 ( $10.0 to less than 23.0$ )	92/13,825	Ref	—	Ref	—	32/4,521	Ref	—	60/9,269	Ref	—
Q2 ( $23.0 to less than 27.9$ )	110/13,765	1.26 (0.95, 1.66)	0.107	1.21 (0.92, 1.60)	0.178	38/4,149	1.29 (0.80, 2.07)	0.290	72/9,494	1.19 (0.84, 1.68)	0.319
Q3 ( $27.9 to less than 33.4$ )	98/13,822	1.13 (0.85, 1.50)	0.405	1.05 (0.79, 1.39)	0.755	29/4,360	0.91 (0.55, 1.51)	0.709	69/9,356	1.10 (0.77, 1.56)	0.592
Q4 (33.4–86.6)	120/13,491	1.58 (1.20, 2.07)	0.001	1.48 (1.13, 1.95)	0.005	45/4,161	1.55 (0.98, 2.46)	0.059	75/9,254	1.42 (1.01, 2.00)	0.045
p-Trend	—	—	0.004	—	0.018	—	—	0.162	—	—	0.079
$particulate matter begin subscript 10 end subscript$
Per IQR (2.3)	—	1.04 (1.01, 1.06)	0.003	1.15 (1.03, 1.30)	0.015	—	1.26 (1.04, 1.53)	0.017	—	1.08 (0.93, 1.26)	0.299
Q1 ( $13.7 to less than 18.0$ )	93/13,810	Ref	—	Ref	—	26/4,245	Ref	—	67/9,493	Ref	—
Q2 ( $18.0 to less than 19.1$ )	95/13,906	1.03 (0.77, 1.37)	0.854	1.01 (0.76, 1.34)	0.946	35/4,546	1.34 (0.80, 2.23)	0.263	60/9,278	0.87 (0.62, 1.24)	0.451
Q3 ( $19.1 to less than 20.3$ )	121/13,715	1.39 (1.06, 1.82)	0.017	1.35 (1.03, 1.76)	0.032	39/4,270	1.60 (0.97, 2.65)	0.067	82/9,331	1.18 (0.85, 1.64)	0.317
Q4 (20.3–28.6)	111/13,472	1.38 (1.05, 1.82)	0.022	1.34 (1.02, 1.77)	0.037	44/4,130	1.84 (1.13, 3.01)	0.015	67/9,272	1.12 (0.80, 1.57)	0.511
P-Trend	—	—	0.004	—	0.008	—	—	0.011	—	—	0.237
$particulate matter begin subscript 2.5 end subscript$
Per IQR (1.3)	—	1.02 (1.01, 1.03)	0.003	1.14 (1.02, 1.28)	0.019	—	1.10 (0.91, 1.33)	0.325	—	1.17 (1.01, 1.36)	0.030
Q1 ( $8.2 to less than 9.3$ )	86/13,865	Ref		Ref		33/4,508	Ref		53/9,284	Ref
Q2 ( $9.3 to or less than 9.9$ )	120/13,605	1.43 (1.09, 1.89)	0.011	1.38 (1.04, 1.82)	0.023	41/4,280	1.33 (0.84, 2.12)	0.223	79/9,289	1.40 (0.99, 1.98)	0.059
Q3 ( $9.9 to or less than 10.6$ )	102/13,650	1.25 (0.94, 1.67)	0.125	1.16 (0.87, 1.55)	0.307	32/4,161	1.05 (0.64, 1.71)	0.858	70/9,389	1.22 (0.85, 1.76)	0.272
Q4 (10.6–20.7)	112/13,783	1.46 (1.10, 1.94)	0.008	1.36 (1.02, 1.80)	0.035	38/4,242	1.24 (0.77, 1.98)	0.377	74/9,411	1.40 (0.98, 2.00)	0.062
p-Trend	—	—	0.031	—	0.118	—	—	0.613	—	—	0.140

Note: —, no data; BMI, body mass index; CD, Crohn’s disease; CI, confidence interval; HR, hazard ratio; IBD, inflammatory bowel disease; IQR, interquartile range; ${NO}_{2}$ , nitrogen dioxide; ${NO}_{x}$ , nitrogen oxides; PM, particulate matter; $particulate matter begin subscript 2.5 end subscript$ PM with aerodynamic diameter $less than or equal to 2.5 micrometers$ ; $particulate matter begin subscript 10 end subscript$ , PM with aerodynamic diameter $less than or equal to 10 micrometers$ ; Ref, reference; UC, ulcerative colitis.

^{^a}

Based on Cox proportional model adjusted for age, sex, ethnicity.

^{^b}

Based on Cox proportional model adjusted for age, sex, ethnicity, assessment centers, household income, smoking status, education, BMI, physical activity, healthy diet, alcohol consumption, baseline related surgery history, medication (use of nonsteroidal anti-inflammatory drugs, amino salicylates, corticosteroids, and immunomodulators).

^{^c}

$p$ -Value $less than 0.05$ was considered statistically significant.