Table 3.

Associations between HAA z-scores and ILA, dyspnoea and cough

	ILA				Exertional dyspnoea				Cough
	n	Events	OR (95% CI)	P-value	n	Events	OR (95% CI)	P-value	n	Events	OR (95% CI)	P-value
HAA z-score
Unadjusted	2406	299	1.39 (1.29, 1.51)	<0.001	3085	793	1.09 (1.03, 1.15)	0.002	3104	307	1.01 (0.92, 1.09)	0.81
Model 1	2352	285	1.39 (1.29, 1.51)	<0.001	3009	779	1.08 (1.02, 1.14)	0.01	3028	303	1.01 (0.93, 1.09)	0.77
Model 2	2352	285	1.40 (1.30, 1.53)	<0.001	3009	779	1.08 (1.02, 1.15)	0.01	3028	303	1.02 (0.93, 1.10)	0.68
Elevated HAA
Unadjusted	2406	299	5.10 (3.47, 7.44)	<0.001	3085	793	1.75 (1.28, 2.37)	<0.001	3104	307	1.07 (0.64, 1.69)	0.78
Model 1	2352	285	5.42 (3.65, 8.00)	<0.001	3009	779	1.52 (1.10, 2.09)	0.01	3028	303	1.06 (0.64, 1.69)	0.80
Model 2	2352	285	5.68 (3.74, 8.60)	<0.001	3009	779	1.37 (0.98, 1.91)	0.06	3028	303	1.11 (0.66, 1.77)	0.68

OR are estimated by logistic regression, P-values are calculated from two-sided Wald tests and error rate is calculated by 10-fold cross-validation. Elevated HAA is defined as the upper fifth percentile of the population (z-score ≥ 1.645). Model 1 is adjusted for study site, smoking status, pack-years, waist circumference, estimated glomerular filtration rate and educational attainment. Model 2 is adjusted for all terms included in model 1 and race, height, BMI, age and sex.

BMI, body mass index; HAA, high attenuation area; ILA, interstitial lung abnormality; OR, odds ratio per z-unit increase or for elevated HAA compared to non-elevated HAA.