Table 2:

Multivariable zero-inflated negative binomial regression analysis of the association between quantitative CT biomarkers and severe exacerbations during 3-year follow-up in the SPIROMICS cohort

	Count component		Inflation component
	Incidence rate ratio (95% CI)	p value	Odds ratio (95% CI)	p value
Age	0·991 (0·974–1·008)	0·281	0·942 (0·885–1·002)	0·058
Sex	1·259 (0·972–1·632)	0·081	1·277 (0·586–2·781)	0·539
Race (White vs other)	0·901 (0·684–1·187)	0·459	2·240 (0·768–6·530)	0·14
Baseline FEV1 (% predicted)	0·986 (0·978–0·993)	0·0002	1·007 (0·982–1·033)	0·579
Smoking status	0·907 (0·658–1·251)	0·553	0·577 (0·210–1·591)	0·288
BMI, kg/m2	1·011 (0·986–1·037)	0·376	0·982 (0·911–1·058)	0·628
History of exacerbations*	1·137 (1·028–1·259)	0·013	0·132 (0·027–0·640)	0·012
SGRQ†	1·006 (0·997–1·015)	0·204	0·921 (0·888–0·955)	<0·0001
CT density gradient	0·979 (0·939–1·020)	0·311	0·758 (0·595–0·967)	0·026
Wall area, %	0·019 (0·0002–1·560)	0·078	0·0003 (0–1654·17)	0·312
Pi10	3·174 (0·942–10·700)	0·062	1·827 (0·040–84·027)	0·758

1535 participants were included in the analysis (1204 with no exacerbations and 331 with at least one acute episode in 3 years) across GOLD stages (0–4), including individuals who never smoked. The zero-inflated negative binomial regression model was adjusted for age, sex, postbronchodilator FEV₁, smoking status, BMI, history of exacerbations, and symptom burden score quantified by SGRQ. SPIROMICS=Subpopulations and Intermediate Outcome Measures In COPD Study. GOLD=Global Initiative for Chronic Obstructive Lung Disease. FEV₁=forced expiratory volume in 1 s. SGRQ=St George’s Respiratory Questionnaire. Pi10=square root of airway wall area of a hypothetical airway with an internal perimeter of 10 mm.

^*Exacerbation history included count of all exacerbation episodes within the year preceding enrolment.

^†The score ranges between 0 and 100, higher scores indicating increased symptom burden.