Lung function decline and incidence of chronic obstructive pulmonary disease in participants with spirometry-defined small airway dysfunction: a 15-year prospective cohort study in China

Table 5 Risk of Progression to Chronic Obstructive Pulmonary Disease in Preserved Spirometry

Group	The number and proportion of participants who developed COPD during follow-up	Unadjusted		Adjusted†
Group		HR (95%CI) *	P value	HR (95%CI) *	P value
Pre-BD lung function
Pre-BD SAD vs. Pre-BD Healthy Control	83/284 (29.2%) vs. 327/2825 (11.6%)	3.00 (2.33–3.81)	< 0.001	2.92 (2.28–3.76)	< 0.001
Pre-BD PRISm vs. Pre-BD Healthy Control	164/726 (22.6%) vs. 327/2825 (11.6%)	2.09 (1.73–2.52)	< 0.001	1.78 (1.47–2.15)	< 0.001
Post-BD lung function
Post-BD SAD vs. Post-BD Healthy Control	45/156 (28.8%) vs. 169/1982 (8.5%)	3.50 (2.52–4.86)	< 0.001	2.88 (2.07–4.02)	< 0.001
Post-BD PRISm vs. Post-BD Healthy Control	48/285 (16.8%) vs. 169/1982 (8.5%)	2.32 (1.68–3.20)	< 0.001	2.07 (1.49–2.88)	< 0.001

BD = bronchodilator; SAD = small airway dysfunction; PRISm = preserved ratio impaired spirometry; HR = hazard ratio; CI = confidence interval
^* Interval-censored proportion hazards regression model was adopted to evaluate the risk of progression to chronic obstructive pulmonary disease
^† Adjusted by age, sex, body mass index, smoking status, smoking index, family history of respiratory diseases, biomass exposure, and occupational exposure history

ISSN: 1465-993X