The association between air pollution and the severity at diagnosis and progression of systemic sclerosis-associated interstitial lung disease: results from the retrospective ScleroPol study

Table 4 Association of air pollution (pre-diagnosis exposure) with the severity of systemic sclerosis-associated ILD at diagnosis: sensitivity analysis

	FVC < 70%^a		TLC < 70%^a		DLCO < 40%^a		CPI > 40^a		Extension > 10%^a
	OR	p value	OR	p value	OR	p value	OR	p value	OR	p value
NO₂	0.99 (0.95–1.03)	0.72	0.98 (0.93–1.03)	0.33	0.97 (0.92–1.02)	0.18	1.00 (0.95–1.05)	0.91	0.96 (0.92–1.00)	0.06
O₃	1.07 (0.98–1.10)	0.21	1.07 (1.01–1.15)	0.03	1.05 (0.98–1.11)	0.16	1.03 (0.97–1.11)	0.36	1.07 (1.01–1.14)	0.03
PM₁₀	0.98 (0.83–1.16)	0.83	1.02 (0.83–1.27)	0.87	0.89 (0.73–1.08)	0.22	1.01 (0.83–1.25)	0.90	0.92 (0.78–1.07)	0.28
PM_2.5	0.94 (0.72–1.23)	0.63	0.83 (0.59–1.18)	0.28	0.91 (0.67–1.25)	0.53	0.74 (0.51–1.03)	0.08	0.89 (0.67–1.16)	0.39

	FVC (% th)^b			TLC (% th)^b			DLCO (%th)^b			CPI^b			Extension^b
	Slope estimate (SE)	t value	p value	Slope estimate (SE)	t value	p value	Slope estimate (SE)	t value	p value	Slope estimate (SE)	t value	p value	Slope estimate (SE)	t value	p value
NO₂	− 0.06 (0.20)	− 0.29	0.78	− 0.09 (0.19)	− 0.49	0.63	0.32 (0.17)	1.88	0.06	− 0.13 (0.15)	− 0.88	0.38	− 0.13 (0.11)	− 1.10	0.27
O₃	− 0.02 (0.27)	− 0.06	0.96	− 0.10 (0.25)	− 0.39	0.70	− 0.51 (0.22)	− 2.29	0.02	0.31 (0.20)	1.56	0.12	0.22 (0.16)	1.39	0.17
PM₁₀	0.30 (0.79)	0.38	0.71	− 0.07 (0.75)	− 0.09	0.93	1.29 (0.67)	1.93	0.06	− 0.54 (0.59)	− 0.92	0.36	− 0.15 (0.45)	− 0.34	0.73
PM_2.5	0.43 (1.22)	0.36	0.72	0.21 (1.20)	0.17	0.86	2.07 (1.05)	1.97	0.05	− 1.87 (0.92)	− 2.03	0.04	0.33 (0.74)	0.45	0.65

CPI: composite physiological index; DLCO: diffusion capacity for carbon monoxide across the lung; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ILD: interstitial lung disease; NO₂: nitrogen dioxide; O₃: ozone; PM₁₀ and PM_2.5: particles with a 50% cutoff aerodynamic diameter of 10 µm and 2.5 µm, respectively; TLC: total lung capacity
^aLogistic regression models
^bMultiple linear models. Models adjusted for: Anti-topoisomerase I Abs positivity, time between first non-Raynaud symptom and ILD diagnosis, and year of ILD diagnosis for FVC and ILD extent on HRCT; socio-economic status of worker, anti-topoisomerase I Abs positivity, time between first non-Raynaud symptom and ILD diagnosis, and year of ILD diagnosis for TLC; time between first non-Raynaud symptom and ILD diagnosis, and year of ILD diagnosis for CPI and DLCO

ISSN: 1465-993X