Table 2.

Associations between emphysema on computed tomography, percent emphysema, and mortality due to lung disease in the Multi-Ethnic Study of Atherosclerosis, 2000–2013.

Underlying cause of death		Emphysema on computed tomography (dichotomous)			Percent emphysema (continuous)
		Absent (N=6,233)	Present (N=538)	P-value	All (N=6,784)	P-value
Respiratory diseases
	Deaths	57	18		77
	Person-years	71,845	6,078		77,750
	Mortality rate per 10,000 person-years	7.9	29.6		9.9
	Hazard Ratiocrude (95% CI)	1.00 (referent)	3.67 (2.16–6.25)	<0.001	1.48 (1.35–1.63)	<0.001
	Hazard Ratioadjusted (95% CI)	1.00 (referent)	2.94 (1.68–5.15)	<0.001	1.51 (1.35–1.69)	<0.001
Chronic lower respiratory diseases
	Deaths	20	17		39
	Person-years	71,845	6,078		77,750
	Mortality rate per 10,000 person-years	2.8	28.0		5.0
	Hazard Ratiocrude (95% CI)	1.00 (referent)	10.11 (5.25–19.46)	<0.001	1.71 (1.55–1.88)	<0.001
	Hazard Ratioadjusted (95% CI)	1.00 (referent)	9.54 (4.70–19.35)	<0.001	1.78 (1.57–2.03)	<0.001
Lung cancer
	Deaths	76	19		95
	Person-years	71,845	6,078		77,750
	Mortality rate per 10,000 person-years	10.6	31.3		12.2
	Hazard Ratiocrude (95% CI)	1.00 (referent)	2.81 (1.70–4.65)	<0.001	1.35 (1.20–1.52)	<0.001
	Hazard Ratioadjusted (95% CI)	1.00 (referent)	1.84 (1.09–3.12)	0.023	1.21 (1.06–1.38)	0.006
All lung diseases
	Deaths	133	37		172
	Person-years	71,845	6,078		77,750
	Mortality rate per 10,000 person-years	18.5	60.9		22.1
	Hazard Ratiocrude (95% CI)	1.00 (referent)	3.16 (2.20–4.56)	<0.001	1.42 (1.32–1.53)	<0.001
	Hazard Ratioadjusted (95% CI)	1.00 (referent)	2.25 (1.54–3.30)	<0.001	1.34 (1.23–1.46)	<0.001

The endpoints were defined by an underlying cause of death of respiratory disease (J00–J99), lung cancer (C33–C34) and, combining these, all lung disease. We also specifically examined mortality due to chronic lower respiratory disease (CLRD; J40–47), which was defined as deaths with COPD, emphysema, chronic bronchitis or asthma as the underlying cause, or, in the context of pneumonia as the underlying cause (J12–18), with these diseases (J40–47) recorded as a contributing cause.

For percent emphysema, hazard ratios reported per interquartile range (4.5%), which is equivalent to the difference between the third quartile (5.7%) and the first quartile (1.2%) of percent emphysema. Models adjusted for baseline age, sex, race/ethnicity, body mass index, site, smoking status, pack-years of smoking, coronary artery calcium score, and educational attainment. Upper limit of normal for percent emphysema defined by reference equations.